United States of America (1944)
Prototype Ground Attack Aircraft – 1 Built
The Vultee XA-41 was a single-engine aircraft that began life as a dive bomber. Months later, its role was changed to a low-level attack aircraft. The XA-41 performed admirably in flight tests, but the United States Army Air Corps (USAAC) eventually decided that the fighter aircraft then in service were already performing well enough in the attack role. Despite its job being erased, the XA-41 continued development as a testbed, showing off the powerful XR-4360 engine it mounted and how much it could carry. The aircraft itself would have been deadly had it been produced in large numbers, as it boasted four 37mm cannons. As the war went on, the XA-41 was still being tested. Throughout the trials, the aircraft had extremely good performance, even being able to outturn a P-51, but its speed wasn’t quite enough for its role. At one point, it was given to the Navy for testing and eventually it would wind up at Pratt & Whitney (PR). At PR, it served as a testbed through the war and was eventually scrapped in 1950.
The XA-41 began as part of a United States Army Air Corps (USAAC) requirement in October 1941 for a new single-seat attack aircraft. The Douglas A-20 Havoc (and soon to be produced North American A-36 Apache) was performing well at the time, but the USAAC wanted something new. The aircraft requested had to be able to reach at least 300mph (482.8kph) at sea level, have a service ceiling of at least 30,000ft (9,144m), and a range of 1,200 miles (1,932km). For the attack role, the aircraft was to have either 37mm, 20mm, or 50. cal guns mounted in the wings. Given this imposing armament, it is likely the aircraft would have attacked soft targets or even been used for tank-busting.
The USAAC commissioned Vultee Aircraft Corporation, Kaiser Fleetwings, and Curtiss to design a new aircraft for the role. Kaiser Fleetwings developed the XA-39, which would have mounted the R-2800-27 engine. Their aircraft didn’t progress beyond the mockup stage. Curtiss reused their naval XTBC-1 prototype for their part, renaming it the XA-40. This also didn’t go beyond the mockup stage. Vultee’s answer was the V-90, a ground attack aircraft mounting the fairly new and powerful R-4360 engine. Interestingly, the XA-41 started off as a dive bomber, despite it being commissioned as an attack aircraft. It isn’t often stated, but the Army had been interested in dive bombers since 1940, going as far as purchasing several Navy designs. The Army bought several SB2D-1 Helldivers in December of 1940 and renamed them the A-25 Shrike. They also had a troubled history with one of Vultee’s own aircraft, the A-35 Vengeance, which they tried numerous times, but to no avail. The XA-41 was most likely a chance for the Army to have a successful dive bomber or attack aircraft. The Army was satisfied with Vultee’s V-90 design and awarded a contract for two prototypes on November 10, 1942. Shortly after a mockup inspection, the Army interestingly switched the role from a dive bomber to a dedicated attack aircraft. The switch was rather abrupt and caused a delay in the development.
On April 30th, a new contract was signed which included a static mockup. Vultee continued construction on the project until the prototype was halfway completed, at which point the Army decided that the most current aircraft, the Republic P-47 Thunderbolt and North American P-51 Mustang, were already quite capable in the attack role. But this wouldn’t be the end of the XA-41. Maj.Gen Oliver P. Echols, Chief of the Material Division, opted not to cancel the program and instead complete it in order to show the true potential of a new attack aircraft with the new R-4360 engine. This decision went through on November 20th, with the prototype ¾ the way through completion. The 2nd prototype was cut at this point and only one would be built (Serial No. 43-35124/5).
On February 11th, 1944, the XA-41 flew for the first time from Vultee Field, California, with test pilot Frank Davis at the controls, and landed at March Field, California. Several flights after this were conducted at the nearby army base. The aircraft was flown by both Vultee and Army pilots, and both agreed it handled well. There were some problems here and there, which Vultee quickly fixed with some additions to the airframe. On June 25, the Army accepted the XA-41. On July 16th, on its 60th flight, the aircraft was ferried to Eglin Field, Florida. Testing proved the XA-41 was an exceptional aircraft, with many great features. The craft had an excellent turn rate, being able to outturn the P-51. For its size, it carried an impressive arsenal of weapons. But the Army wanted an attack aircraft that could also defend itself if the need would arise, and the 350mph (563.2 km/h) of the XA-41 wasn’t that impressive compared to other aircraft in service. The United States Navy became interested in the XA-41 at some point and the prototype was given to them for testing at Patuxent River, Maryland. The Navy wanted to see if the aircraft could be flown from aircraft carriers. After the Navy briefly tested it, the XA-41 was given to Pratt & Whitney (PR) on August 22, 1944. It was obvious at this point that the XA-41 would never see combat, but would remain in the US as a testbed aircraft. Serving with PR, it was used as a flying testbed for their R-4360 engine, as well as having a supercharger mounted. As testing continued, the aircraft was purchased by PR on October 9 and re-registered as NX6037N. There are few documents that reference the XA-41 post-war. The only thing mentioned is that the sole XA-41 was finally scrapped in 1950, having served for many years at PR.
The XA-41 was a conventional single-engine aircraft. It had a slight gull wing and a tail sitter configuration. The landing gear in the wings would retract inboard and was placed widely to allow better landing performance. During development, the tail wheel had doors installed to completely cover it in-flight. The cockpit was placed far forward and raised to allow the pilot to see over the engine, giving him better visibility when attacking ground targets. The ventral tail had an extension that spanned most of the length of the aircraft. This was added during development. A spinner was also added at some point. The XA-41 mounted the PR XR-4360 Wasp Major engine, which was the main reason the Army and PR were so interested in the project.
For armament, the XA-41 had four M2 Browning .50 cal machine-guns mounted in the wings. For the attack role, it was meant to mount four more 37mm cannons (sources don’t mention what particular kind of gun) in the wings. All armament in the wings was placed outside of the propeller’s range. For bombing, the XA-41 had a bomb bay that could carry four 500Ibs bombs, a torpedo, additional fuel, or two 1,600Ibs weapons. In total, it had up to 6,500Ibs of ordnance. Documents mention that up to 1,100Ibs of additional bombs could be mounted to the wings. The aforementioned competing XA-39 only sported the four Brownings, two 37mms, as well as a predicted carrying capacity of six 500Ibs bombs.
XA-41 – [The sole prototype built, used as a testbed for the XR-4360 engine.]
United States of America – The United States Army Air Corps would have operated it had it entered production. After serving as a testbed for the Army, the Navy and Pratt & Whitney also did tests with the aircraft.
The Douglas XTB2D-1 “Skypirate” was a large, single-engine torpedo bomber built for use on the Midway class carriers during World War 2. At the time, it was the largest aircraft to be used aboard a carrier, dwarfing even two-engine designs. Unfortunately for the Skypirate, engine troubles, little support from the US Navy (USN), and numerous setbacks with the construction of Midway-class carriers nearly doomed it from the start. By the time it was airworthy, it was trying to fill an obsolete role which other aircraft, such as the TBF/TBM Avenger, already filled adequately. Work continued after the war, with several attempts to revive the program but it proved to be too costly and the Skypirate program was finally cancelled in 1947, with the two prototypes being scrapped in 1948.
With engagements such as the Battle of the Coral Sea and the hunt for the Bismarck, the effectiveness of torpedo bombers, such as the TBF/TBM Avenger and Fairey Swordfish, was clear. With the announcement of the large Midway-class carriers, the possibility of a new torpedo-bomber/scout bomber came about. In February 1942, a competition was put forward by the Navy for this role. The Douglas Aircraft Company, based in Southern California, proposed the Skypirate. The single-engine Skypirate was picked from eight different designs, most of which were two-engined. The Bureau of Aeronautics (BuAer) wasn’t expecting a single engine design to be submitted, assuming the specified massive carrying capacity would require a two-engine design. The program was being headed by Ed Heinemann as lead designer and Bob Donovan as the chief engineer, who would be on the project until the end.
In November of 1942, Douglas was given permission to begin production of two prototypes and a mockup of the XTB2D-1 (then called the Devastator II, before being changed to Skypirate). Delays in the development of the Midway class would continue to hamper the Skypirate throughout its life. The finished product was a formidable aircraft, capable of carrying four torpedoes from land or two torpedoes from a carrier, the former being four times the carrying capacity of the TBM Avenger. In March and May of 1943, the mockup was inspected and an order for 23 production aircraft was put in. This was enough for a single squadron to operate from a Midway carrier. Problems began about this time, with the delivery of engines and propellers being delayed. By 1944, the Skypirate was still not airborne and it was obvious it wouldn’t be operational anytime soon. With earlier torpedo bombers performing adequately, a lack of support from the Navy, most of the Japanese fleet in shambles and continued delays with the Midway class (which would eventually sail after the war), the 23 production planes were cancelled. On February 18th, 1945, the first Skypirate was rolled out of the production facility, being completed on March 13th and finally going airborne on May 8th. Neither of the prototypes had any defensive armaments, but they were tested with torpedoes and drop tanks. Although no production was to ever start, the Skypirates would continue flying until the end of the war. During one such flight in June of 1945, a Skypirate was damaged mid-flight, but the craft was brought down safely. Engine problems were a frequent issue with the Skypirate and propeller problems would ground it in August of 1945, not flying again until after the war.
Postwar, the aircraft industry changed with the introduction of jet aircraft, thus eliminating the need for many prototypes being developed during the war. The Skypirate was no exception. With the torpedo bomber role now fading, the Douglas firm looked at other options to revive their Skypirate. Some ideas included using the Skypirate for an electronic warfare role or even as an anti-submarine aircraft (a role overtaken by another piston engine aircraft, the Grumman AF Guardian), but none of these propositions ever managed to become reality. As the Cold War was just beginning, the Skypirate program ended in 1947 and the 2 prototypes were scrapped in 1948.
The Skypirate is most likely the largest single-engine aircraft to ever be designed for carrier operations. In comparison, the twin-engined B-25 Mitchell medium bomber measured around the same in length and width.
The initial Skypirate design had an internal bomb bay, which the prototypes dropped in favor of four external Mark 51 Mod 7 bomb hardpoints. These hardpoints could carry a range of weapons including 500Ib-2000Ib bombs, torpedoes, depth charges, mines or even incendiary bombs. The use of up to 4 Mk.13 Torpedoes (from land) were planned had it entered production. The Skypirate could alternatively carry up to 8,400Ibs of bombs. For offensive armament, the Skypirate had 4 M2 Browning machine guns in the wings. For defense, it had a Firestone model 250CH-3 remote turret behind the cockpit which carried 2 M2 Brownings and a turret in the back of the lower fuselage which carried a single M2 Browning. The lower turret was remotely fired through electronic control and powered hydraulically. Drawings indicate that Mark 2 Gun Containers could be added for extra forward firepower but none were ever attached during testing. 300 gallon drop tanks were also fitted during testing and could have been used had the craft been operational.
Along with such an impressive weapons payload, the Skypirate was full of advancements which would have improved its performance. To get such a large aircraft off the ground, the Skypirate was powered by a single Pratt & Whitney XR-4360-8, the largest radial engine ever built up to that time. The engine had a unique exhaust style that combined the exhausts in alternating rows to lower the effects of backpressure. Being a carrier-based aircraft, the Skypirate had folding wings as well as a catapult hook. The inclusion of a tricycle landing gear was also interesting, as it helped with bomb loading and carrier space. Most single engine aircraft of the time preferred using a tailwheel. The Skypirate had large flaps that extended the length of wingspan. The outer flaps served as ailerons while the midsection flaps were used as dive flaps. The dive flaps could also be lowered to help the aircraft cruise or assist in turning to help ease the stress off the aircraft when fully loaded. To assist with bombing or flight in general, a Type 3 Sperry vacuum-controlled, hydraulic autopilot was also to be added. A de-icing system was also added that pumped hot air over the wings and tail section.
The planned modifications of the prototypes are interesting to note. The 2nd prototype (Bu.36934) differed from the first, having a shorter tail of 8.6 ft, compared to the regular 10.5 ft tail of the original design. This was done most likely to conserve valuable space when inside a carrier. Along with these differences, plans to fit a jet engine in the fuselage of the 2nd prototype were made, but nothing ever came to fruition. The first prototype (Bu.36933) had a larger tail and was planned to be converted for the scout bomber role. These plans included adding cameras onboard. As with the jet engine designs, these also never came to be.
XTB2D-1 Bu.36933 – Prototype version, lacked any armament
XTB2D-1 Bu.36934 – The 2nd prototype. The tail was shortened to 8.6 ft. Also lacked any armament.
TB2D-1 – Proposed production version, 23 were ordered and planned production was to be 100 built every month. These versions were to be fitted with four .50 caliber machine guns in the wings, two in a Firestone power turret and one remotely controlled in the ventral hull. Eventually, the production versions were cancelled in favor of higher priority projects.
United States of America – Slated to be used aboard the Navy’s Midway-class carriers, with the end of the war and other setbacks, the XTB2D-1 was never used operationally.
70 ft / 21.3 m
46 ft / 14 m
22 ft 6 in / 6.9 m
605 ft² / 184.4 m²
1x 3,000 hp ( 2240 kW ) XR-4360-8
1x 8 bladed Hamilton Standard contra-rotating propeller
501 US gal / 1896 L
28 US gal / 106 L
18,405 lbs / 8350 kg
28,545 lbs / 12950 kg
34,760 lbs / 15765 kg
Rate of Climb at Sea Level
1,390 ft / 425 m per minute
Time to 10,000 ft / 3048 m
8.2 minutes (Normal) 10.2 minutes (Military)
Time to 20,000 ft / 6096 m
22.3 minutes (Normal) 26.5 minutes (Military)
340 mph / 550 km/h at 15,600 ft / 4755 m
168 mph / 270 km/h
312 mph / 500 km/h (with torpedoes)
1,250 mi / 2010 km (Torpedoes)
2,880 mi / 4635 km (Maximum)
Maximum Service Ceiling
24,500 ft / 7470 m
4 Browning M2 machine guns mounted in the wings (1600rds)
United States of America (1974)
Prototype Supersonic Heavy Bomber – 4 Built
The B-1A program arose out of a need for a long-range, supersonic, low-flying heavy bomber. The program’s initial development was pushed forward through an ever-shifting geopolitical landscape, as well as opposition and contention among the the top levels of the U.S. government. Even with advanced features such as variable sweep wings, and variable air intake and exhaust capability, it was derided as a ‘dinosaur’ in the age of ICBMs. The opposition and political infighting nearly ended the Lancer, before it was given a miraculous second chance.
The origin of the Rockwell B-1 can be traced back to 1961, when the Air Force began to consider alternatives to the North American B-70 Valkyrie, which had just been downgraded from production to test aircraft status. At that time, the long range strategic missile was assumed to be the weapon of the future, with manned long-range bombers being relegated to a secondary role. The B-70 had been designed to fly at extremely high altitudes and at Mach 3 speeds, and increasingly effective Soviet anti aircraft defenses had made such an aircraft rather vulnerable.
Nevertheless, the Air Force commissioned several studies to explore possible roles for manned bombers in future planning. If successful, these would replace the B-52. At this time, the ability to fly through enemy airspace at extremely low altitudes was was thought to be the key for survival in the face of sophisticated air defenses.
The first such study was known as the Subsonic Low Altitude Bomber (SLAB), which was completed in 1961. It envisaged a 500,000 pound fixed-wing aircraft with a total range of 11,000 nautical miles, with 4300 nm of these miles being flown at low altitudes. This was followed soon after by the Extended Range Strike Aircraft (ERSA), which had a weight of 600,000 pounds and featured a variable sweep wing. The ERSA was supposed to be able to carry a payload of 10,000 pounds and achieve a range of 8750 nautical miles, with 2500 of these miles being flown at altitudes as low as 500 feet. In August of 1963, a third study known as Low-Altitude Manned Penetrator(LAMP) was completed. It called for a 20,000 payload and a 6200 nautical mile range, 2000 miles being flown at low altitude. None of these projects ever got beyond the basic concept stage.
In October of 1963, the Air Force looked over these proposals and used the results as the foundation of a new bomber proposal, termed Advanced Manned Precision Strike System (AMPSS). In November of that year, 3 contractors were issued Requests for Proposals for the AMPSS. The companies were Boeing, General Dynamics, and North American. However, Secretary of Defense Robert McNamara kept a tight rein on funds, and expressed doubts about the assumptions behind AMPSS, so the RFPs only involved basic concept studies and did not focus on a specific aircraft. In addition, the contractors all agreed that some of the suggested USAF requirements either did not make much sense or else were prohibitively costly.
In mid-1964, the USAF had revised its requirements and retitled the project as Advanced Manned Strategic Aircraft (AMSA). The AMSA still envisaged an aircraft with the takeoff and low-altitude performance characteristics of the AMPSS, but in addition asked for a high-altitude supersonic performance capability. The projected gross weight for the aircraft was 375,000 pounds, and the range was to be 6300 nautical miles, 2000 of which would be flown at low altitude.
Secretary McNamara was never very excited about the AMSA, since he thought that strategic missiles could do a better job of “assured destruction” than manned bombers, and thought that the cost of the AMSA would probably be excessive. Nevertheless, there was a potential gain in avionics and propulsion technology that could be achieved if the project were to proceed, and McNamara released a small amount of funding for preliminary AMSA studies. The airframe for the AMSA would be worked on by Boeing, General Dynamics, and North American, whereas Curtiss-Wright, General Electric, and Pratt & Whitney would work on the engines. Both IBM and Hughes aircraft looked at potential avionics systems. These contractors issued their reports in late 1964. General Electric and Pratt & Whitney were given a contract to produce two demonstrator engines, but no airframe and avionics contracts were issued at that time.
A bit of confusion entered the picture when the Defense Department selected the FB-111A as the replacement for the B-52C, B-52F, and B-58. The Air Force had not requested a bomber version of the controversial F-111, and was not all that enthusiastic about the choice. Nevertheless, a low-cost interim bomber did have some attractive features, and the Air Force went along with the choice of the FB-111A provided it did not interfere with AMSA development.
By 1968, an advanced development contract was issued to IBM and the Autonetics Division of North American Rockwell. On September 22, 1967, North American Aviation had merged with Rockwell Standard Corporation to create North American Rockwell. Earlier in that year, the Joint Chiefs of Staff had recommended the immediate development of the AMSA, but Secretary McNamara was still opposed, preferring instead to upgrade the existing FB-111 and B-52 fleet. McNamara vetoed the proposal.
When Richard Nixon became President in January of 1969, his Secretary of Defense Melvin Laird reviewed Defense Department needs and announced in March of 1969 that the planned acquisition of 253 FB-111s would be reduced to only 76, since the FB-111 lacked the range and payload required for strategic operations, and recommended that the AMSA design studies be accelerated.
The AMSA was officially assigned the designation B-1A in April of 1969. This was the first entry in the new bomber designation series, first created in 1962.
New Requests For Proposals were issued in November of 1969. IBM and Autonetics were selected for the avionics work on December 19. The selection of airframe and engine contractors was delayed by budget cuts in FY 1970 and 1971. On December 8, 1969 North American Rockwell and General Electric were announced as the winners of the respective airframe and engine contracts for the B-1A.
The original program called for 2 test airframes, 5 flyable aircraft, and 40 engines. This was cut in 1971 to one ground test aircraft and 3 flight test articles (74-0158/0160). First flight was set for April of 1974. A fourth prototype (76-1074) was ordered in the FY 1976 budget. This fourth plane was to be built to production standards. At one time, some 240 B-1As were to be built, with initial operational capability set for 1979.
The fuselage of the B-1A was fairly slim, and seated a crew of four in the nose. There was a large swept vertical tail, with a set of all-flying slab tailplanes mounted fairly high on the vertical tail. The aircraft’s fuselage blended smoothly into the wing to enhance lift and reduce drag. In addition, the fuselage was designed to reduce the aircraft’s radar cross section in order to minimize the probability of detection by enemy defenses.
In order to achieve the required high-speed performance and still be able to have a good low-speed takeoff and landing capability, a variable-sweep wing was used. This made it possible for the aircraft to use short runways that would be inaccessible to the B-52. The outer wing panels were attached to a wing carry-through attachment box which faired smoothly into a slim, narrow fuselage. Each outer wing had full-span slats and slotted flaps, but used no ailerons. Lateral control was provided by a set of spoilers on the wing upper surface, acting in conjunction with differential operation of the slab tailplanes.
The engines were four afterburning General Electric F101-100 turbofans. The engines were installed in pairs inside large nacelles underneath the wing roots,, and close to the aircraft’s center of gravity to improve stability while flying at high speed through highly-turbulent low-altitude air. The nacelles were far enough apart so that the main landing gear members could be installed in the wing roots between them with enough clearance to retract inwards. In order to achieve the required Mach 2 performance at high altitudes, the air intake inlets were variable. In addition, the exhaust nozzles were fully variable.
Initially, it had been expected that a Mach 1.2 performance could be achieved at low altitude, which required that titanium rather than aluminum be used in critical areas in the fuselage and wing structure. However, this low altitude performance requirement was lowered to only Mach 0.85, enabling a greater percentage of aluminum to be used, lowering the overall cost. Titanium was used primarily for the wing carry-through box, the inner ends of the outer wings incorporating the pivots, and for some areas around the engines and rear fuselage.
Eight integral fuel tanks were planned, one in each outer wing panel, and the rest in the fuselage. About 150,000 pounds of fuel could be carried. There were three 15-foot weapons bays in the lower fuselage, two ahead and one behind the wing carry-through box. Each bay could carry up to 25,000 pounds of conventional or nuclear weapons. The total weapons load was almost twice what a B-52 could carry. All of the offensive weapons were to be carried internally, with no provision for externally-mounted pylons. A key weapon was to be the AGM-69A SRAM (Short-Range Attack Missile), 8 of which could be carried on a rotary launcher in each of the weapons bays.
No defensive armament was planned, the B-1A relying on its low-altitude performance and its suite of electronic countermeasures gear to avoid interception.
An extensive suite of electronics was planned, including a Litton LN-15 inertial navigation system, a Doppler radar altimeter, a Hughes forward-looking infrared, and a General Electric APQ-114 forward-looking radar and a Texas Instruments APQ-146 terrain-following radar.
The B-1A carried a crew of four–a pilot, copilot, offensive systems officer, and defensive systems officer. The crew escape system resembled that of the F-111 crew escape module. In an emergency, a capsule containing all four crewmembers would separate from the aircraft and be steered and stabilized by various fins and spoilers. A rocket motor would fire and lift the capsule up and away from the aircraft. Three parachutes would then open and would lower the capsule along with the crew safely to the surface. Once down, the capsule would serve as a survival shelter for the crew members.
The B-1A mockup review occurred in late October of 1971. There were 297 requests for alterations.
The first B-1 flight aircraft (74-0158) rolled out from USAF Plant 42 at Palmdale, CA on October 26, 1974. It made its first flight on December 23, 1974, a short hop to Edwards AFB where the flight testing was to be carried out. The crew was Rockwell test pilot Charlie C. Bock,; Jr, Col. Emil Sturmthal, and Richard Abrams. The third aircraft (74-0160) was to be the avionics testbed and flew for the first time on March 26, 1976. The second aircraft (74-0159) was initially used for some static ground testing and did not make its first flight until June 14, 1976.
The B-1A test program went fairly smoothly. However, there were numerous modifications introduced throughout the program and some items of additional equipment were added. The avionics suite of the B-1A was perhaps the most complex yet used on an aircraft. The Initial Operational Test and Evaluation tests were successfully passed in September of 1976. The Phase 1 flight test program was completed on September 30, 1976. In December of 1976, the Air Force concluded that the B-1A was to go into production, with contracts placed for the first three aircraft and plans were made for an initial Block 2 production batch of 8 aircraft.
It seemed that the B-1A was well on its way to a full production run of 240 aircraft. However, the cost of the B-1A program began to escalate, and there were still some unresolved issues concerning the avionics suite. In 1970, the estimated per-unit price was $40 million, and by 1972, the cost had risen to $45.6 million. Although this sounds like small-change by today’s standards, this was considerably greater than the figure for any previous production aircraft. Moreover, by 1975, this number had climbed to $70 million.
Alarmed at these rising costs, the new presidential administration of Jimmy Carter (which had taken office on January 20, 1977) began to take a second look at the whole B-1A program. On June 30, 1977, President Carter announced that plans to produce the B-1A would be cancelled, and that the defense needs of the USA would be met by ICBMs, SLBMs, and a fleet of modernized B-52s armed with ALCMs. President Carter genuinely wanted to reduce the arms race, but he was unaware at the time of the secret projects that would ultimately lead to the F-117A stealth attack aircraft and the B-2 Spirit stealth bomber.
Despite the cancellation of the production program, the Carter administration allowed the flight testing of the B-1A to continue. Most of the effort involved the avionics, in particular the defensive systems. In addition, General Electric continued to work on improvements for the F101 engine, and most of the contractors kept their engineering teams intact. Perhaps most important, work continued in reducing the radar cross section of the aircraft. Less than a month after the cancellation, 74-0160 launched a SRAM on July 28, 1977 at an altitude of 6,000 feet over the White Sands missile range. This aircraft was later modified with an advanced electronic countermeasures system mounted in a dorsal spine, and Doppler beam sharpening was added to the forward-looking radar. 74-0158 had achieved Mach 2.0 in April of 1976, and after completing its stability and control tests was placed in storage in 1978. On October 5, 1978, 74-0159 achieved a speed of Mach 2.22, the highest speed achieved during the B-1A program.
74-0158 was retired from flying in April of 1981 after having flown 138 sorties, the largest number of flights of any of the prototypes. By this time, it had acquired a three-tone desert camouflage scheme. It was eventually dismantled and used as a weapons trainer at Lowry AFB.
74-0159 was later used as a flight test article in the B-1B program. It was modified by having B-1B flight control system features installed. It began flying on March 23, 1983. Unfortunately, it crashed on August 29, 1984 when the aircraft’s center of gravity got unbalanced during fuel transfer management procedures, causing it to lose control. The escape capsule deployed successfully, but the parachute risers did not deploy properly. The capsule hit the ground at a steep angle, so steep that the inflatable cushions could not shield the impact. Chief test pilot Doug Benefield was killed, and two other crew members were seriously injured.
74-0160 was later converted to a ground trainer under the designation GB-1A and is now on display at the Wings Over The Rockies Air and Space Museum (formerly Lowry AFB), near Denver, Colorado.
76-0174 had been ordered to serve as a pre-production B-1A aircraft and was configured with full avionics systems. When the B-1A program was cancelled, work on this aircraft was well under way. Unlike the first three B-1s, 76-0174 was equipped with four conventional ejector seats in place of the escape capsule. This change was made after tests had determined that the crew escape module was unstable if ejected at speeds above 347 knots. It flew on February 14, 1979 and carried out 70 sorties. This plane was later used as a test article in support of the B-1B program. It resumed flying on July 30, 1984. Externally, the main change was the removal of the long dorsal spine but many of the B-1B avionics systems were installed internally. It is now on display at the USAF Museum at Wright Patterson AFB in Ohio.
B-1A – The initial prototype run of four aircraft
U.S. Air Force – The sole operator of the B-1A was the USAF
(at max sweep)
78 ft 2.5 in / 23.84 m
(at min sweep)
136 ft 8.5 in / 41.67 m
143 ft 3.5 in / 43.8 m
34 ft 0 in / 10.36 m
1,950 ft² / 181.2 m²
4x General Electric F101-GE-100 turbofans, 17,390 lbf dry, 30,000 lbf with afterburner
29,755 US Gal / 11,2634 L
389,000 lb / 176,450 kg
Maximum Take Off Weight
395,000 lb / 179,170 kg
Mach 2.2 / 1,688 mph / 2716.5 kmh at 50,000 ft / 15,240 m
Maximum Service Ceiling
62,000 ft / 18,900 m
1 pilot, 1 copilot, 1 offensive systems officer, 1 defensive systems officer
United Kingdom (1963)
Utility Aircraft – 153 Built
The Short SC.7 Skyvan, nicknamed the “Flying Shoebox” and “The Shed”, is a British-built general-purpose transport.
It features an odd, boxcar-like fuselage which FlightGlobal listed as “one of the twelve strangest-looking aircraft ever built”. Air Vice Marshal Ron Dick describes it in Air & Space Magazine as “Uncompromisingly chunky and angular, its freight container body hangs from wings which could have been shaped in a sawmill, and its twin fins were mere upright planks tacked on as if in afterthought.”
Despite this, the Skyvan did have its merits as a robust light transport aircraft. Originating from the Miles Aerovan and the failed Miles HDM-106 Caravan, it first took to the air in 1963, remaining in service to this day with militaries and civilian operators alike.
In 1958, Short (at the time Short Brothers & Harland Ltd) was approached by F.G. Miles Ltd., an offshoot of the bankrupt Miles Aircraft, looking for help to produce the H.D.M. 106 Caravan. The H.D.M. 106 was a development of the H.D.M. 105, a Hurel-Dubois extended-wing Miles Aerovan. Short, trying to diversify their line consisting of seaplanes, evaluated this offer, and refused it, finding it too advanced.
In June of 1959, Short formed a Light Aircraft Division. The first project of this newly formed department was a privately funded venture, a “general purpose transport with van-type loading”. Using data obtained from the failed Miles HDM.106 Caravan, they began the design of what is now known as the Short SC.7 Skyvan.
By August of 1960, Short had released further detail on the aircraft, and named it the “Skyvan”. Construction of the prototype began in 1960 at Queens Island, Belfast. Manufacturing was slow, as production was focused on the SC.5 Belfast heavy freighter. Initially, two aircraft were built, and the first made its maiden flight on January 17, 1963. As of the time of writing in September 2018, the Skyvan is still in service with many nations around the globe.
There are two extended versions of the Skyvan, the Short 330 and 360.
The Skyvan is a high-winged, twin-engine, fixed tricycle landing gear utility aircraft with twin rudders and a box-like fuselage. The box fuselage allows for a large rear door for loading and unloading freight. This also gives it a good efficiency, as it is capable of carrying over 1 ½ tons of payload. Although not a true STOL aircraft, it can take off from a half mile (804.67 m) field or strip. Simplicity and ruggedness are the primary features of the Short SC.7 Skyvan. It can be used for many purposes, including short-haul freight, passenger transport, skydiving, and much more.
With the prototypes being powered by 390 hp Continental piston engines and Turboméca Astazou 2 turboprops, and the initial production run being powered by the Turboméca Astazou XII turboprops, the Skyvan needed an upgrade. The Skyvan 3 was re-engined with Garrett AiResearch TPE331 in order to improve airfield performance in hot and high-altitude conditions. This was done as the previous engines were shown to be inadequate for Ansett-MALs New Guinea routes, as they only delivered 630 shp of the promised 690 shp. Ansett-MAL was a primary factor for this decision, being a key customer, but the upgrade also provided vastly improved engine handling for both the pilot and the aircraft mechanic.
Apart from the re-engining, various other improvements were made to the Skyvan. The increased power required larger trim tabs and a new out-of-trim compensator in the elevator. Larger fuel tanks for the increased fuel consumption (and the fact that installed consumption provided 5% better) resulted in an increased range. The increased weight of the engine resulted in a reappraisal of the airframe, a simplified design, and surprisingly, a lower empty weight. The cockpit layout was also cleaned up and a central warning system was added. All these upgrades were very well received by Short’s pilots, engineers, and customers alike.
The Skyvan has had a long history, serving around the world with various militaries. Of particular interest is the Skyvan’s service with the Prefectura Naval Argentina, the Argentine Coast Guard.
The Argentine Coast Guard operated 5 Skyvans out of Port Stanley and Pebble Island, where two were lost. The Coast Guard utilized their STOL capabilities for communication and light transport between the mainland and the occupied Falkland Islands.
A raid was mounted by SAS’s D Squadron to destroy the ground attack Pucaras planes based in the Falklands. On the night of the 10th, men of the Squadron’s Boat Troop were put ashore to provide reconnaissance. On Friday the 14th, HMS Hermes, her escort HMS Broadsword, and HMS Glamorgan separated from the carrier battle group, approaching Pebble Island by night. As Glamorgan approached to provide fire support, the 48 men of the SAS task force took off in Sea Kings. They landed, moving by foot to the airstrip, and by morning, all the aircraft there were disabled or destroyed with explosive charges. In the meantime, Glamorgan provided fire support, and the SAS withdrew. A brief Argentine counter-attack stopped when the officer in charge was shot and, with two men slightly wounded, the SAS escaped. The raid was successful, resulting in the loss of six Pucaras, four T-34C Mentors, and a single Coast Guard Skyvan (serial number PA-50), and halted the use of the airstrip. The remains of the Skyvan are still visible to this day.
The other destroyed Skyvan, PA-54, crashed in Stanley, Falkland Islands (then Puerto Argentino) on June 5th, from a failure of the nose landing gear during the landing at the racecourse of Puerto Argentino. Afterwards, sometime between the 12th and 13th of June, it was destroyed by 105mm British artillery fire and was written off.
Skyvan 1 – 2 built. Skyvan prototype powered by a pair of Continental GTSIO-520 piston engines.
Skyvan 1A – Single re-engined Skyvan 1 powered by a pair of Turboméca Astazou 2 turboprops.
Skyvan 2 – Initial production run Skyvan powered by a pair of Turboméca Astazou XII turboprops. 8 built for British European Airways until 1968.
Skyvan 3A – Skyvan 3 with increased Maximum Take-Off Weight (MTOW).
Skyvan 3M – Military transport variant.
Skyvan 3M-200 – Skyvan 3M with increased MTOW of 15,000 lbs / 6800 kg.
Skyvan 3M-400 – Modernized militarized Skyvan. There are many subvariants of the 3M-400, but it is unclear how they differ.
Skyvan 3 C1 – 10 built. British Army designation.
Skyliner – Luxury passenger transport variant.
Seavan – Maritime patrol Skyvan.
Civilian – Commercial use of the Skyvan includes: Questor Surveys, Olympic Airways, Pink Aviation Services, NASA, Aeralpi, StoLine Systems, Wein Consolidated Airlines, Summit Air, Northern Consolidated Aviation, GB AirLink, Air Forum, Gulf Air, Nomad Air, British European Airways Scottish Division, Laboratory of Space Technology, Invicta Aviation, Skylift, Bravo Partners Inc., North Star Air Cargo, Forrester Stephen Aviation, Skydive DeLand, British Air Services, Bougair, Skyhawk, Ansett-MAL, and more. As well, some are privately operated.
Argentina – The Argentine Coast Guard purchased 5 Skyvan 3M-400-7s, which saw service in the Falklands War. Two were lost, with one being damaged by naval gunfire at Stanley, Falkland Islands on the night of May 3rd, 1982, and not repaired. The other was destroyed during the Pebble Island raid, by D Squadron SAS on the morning of May 15th.
United States of America – 2 copies of the Skyvan 3, serial numbers 90-00042 and N430NA.
Austria – 2 copies of the Skyvan 3-400-1, serial numbers 5H-TA and 5H-TB delivered to the Austrian Air Force.
Oman – 16 copies for the Royal Air Force of Oman. These include the Skyvan 3M-400-23, 3M-400-22, 3M-400-II, 3M-400-4, and 3M.
Ecuador – Two Skyvan 3M-400-6 produced for the Aviacion del Ejercito Ecuatoriano (Air Force of the Ecuadorian Army).
Indonesia – 4 copies of Skyvan 3M-400-5s sold to the Indonesian Air Force
Nepal – 7 copies purchased for the Nepalese Air Force, consisting of 3 SC.7 3-100s and 4 3M-400-9s.
Thailand – 4 copies for the Thai Army and Police. Variants include the 3M-400-II and the 3M-400-17.
Mexico – The Mexican Air Force purchased 6 copies made up of 4 Skyvan 3M-400-IIs and 2 Skyvan 3Ms.
Singapore – 6 copies made for the Singapore Air Force, half of which are Skyvan 3M-400-16s, and the other half being 3M-400-15s.
Yemen – The Yemen Air Force operated 2 copies of the Skyvan 3M.
Ghana – 6 copies for the Ghana Air Force of Skyvan 3M-400s
Japan – 2 copies of Skyvan 3M-400-IIs are operated by the Japanese government.
Mauritania – 2 Skyavan 3Ms made for the Mauritania Islamic Air Force.
Venezuela – The Venezuelan government operated 6 Skyvan 3Ms.
Saudi Arabia – Purchased 4 Skyvan 3Ms.
Lesotho – Purchased 2 Skyvan 3s for the Lesotho Defence Force – Air Squadron
Panama – Bought a single Skyvan 3M for the National Air and Naval Service of Panama.
Botswana – The Botswana Defense Force – Air Wing purchased 2 Skyvan 3s.
Ciskei – Purchased two Skyvans, serial numbers ZS-LFG and ZS-KMX, relegated to civil use.
Guyana – Purchased 4 Skyvan 3s.
Malawi – Malawi purchased a single Skyvan 3M, serial number 7Q-YAY.
Maldives – The Maldives National Defense Force purchased one Skyvan 3.
United Arab Emirates – 3 Skyvan 3s were purchased by the United Arab Emirates Air Force.
The VL Pyörremyrsky (translates as Hurricane) was a prototype Finnish fighter plane designed to keep up with its contemporaries. It was to be domestically produced, using wood, but using the same engine as the Bf 109 G. Due to limitations brought about due to the war, only one prototype was produced and it wasn’t ready until the end of 1945.
Development and History
As Finland found itself still at war with the Soviet Union in 1942, with no end in sight, it turned to ways to bolster its military force. In order to become as self sufficient as possible, it was engaged in various projects for domestically designed and produced weapons systems. The VL Myrsky project was severely behind schedule and the air force realised that it would be outclassed by the newer Soviet aircraft by the time it reached production. With this in mind, it placed order number 2012/42 on 26th November 1942 for a new aircraft design, under the name Pyörremyrsky.
The State Aircraft Factory (Valtion Lentokonetehdas) was tasked with producing the new fighter and Captain of Engineering Torsti Verkkola was assigned chief designer of the team. The main premise was that the aircraft was to be made out of wood, as much as was possible, and that it was to be comparable with the German Messerschmitt Bf 109G. Verkkola used the Bf 109 as the base for his design, making modifications to allow it to be produced with local skills and materials. However, as the war dragged on, and the Finnish Air Force required more proven aircraft, as well as repairs to the planes already in service, the Pyörremyrsky found itself given a lower priority.
Upon the cessation of hostilities between Finland and the Soviet Union in September 1944, the Pyörremyrsky project had only a partially completed prototype and the Ministry of Defence (puolustusministeriö) cancelled the advance order of 40 aircraft, as well as the second prototype on the 29th September, but they did allow the first prototype to be completed. In Autumn 1945 the prototype, now christened PM-1 (which led to the nickname Puu-Mersu or Wooden Messerschmitt), was ready for pilot tests. On the 21st of November 1945, Luutnantti (Lieutenant) Esko Halme took off in PM-1 from Tampere-Härmälän airfield. The flight only lasted 25 minutes as part of the engines’ exhaust system came loose, forcing an emergency landing as Lt. Halme was unable to see through the exhaust blowing into his cockpit. Despite the incident, Halme reported good flying controls and characteristics. PM-1 would do 2 more test flights at Härmälän airfield before moving to Kuorevesi for Air Force testing. In total 31 test flights were performed, amounting to 27 hours of flight time. All 8 pilots reported the same, smooth and controlled flying characteristics, good speed and turning ability, however it was not quite up to the same performance of the Bf 109 G but close enough. The last flight of PM-1 was on the 22nd of July 1947, when Kapteeni (Captain) Osmo Kauppinen took off for a 20 minute general test flight. After this it was put into storage until it was officially removed from the Air Force’s rolls on the 1st April 1953. This was mainly due to the lack of ability to source new engine parts as part of the armistice Finland signed with the Allies forbade them from receiving military goods from Germany, as well as the decline of the piston aircraft as a fighter.
The Air Force didn’t want such a unique piece of Finnish aviation history to be scrapped however and ordered it to be preserved. It was sent to the State Aircraft Factory’s depot and was refurbished in the early 1970’s and sent to the Finnish Air Force Museum, where it is still on display.
The experiences learnt with the Pyörremyrsky were not totally in vain or wasted as the basic design was used in the development of the VL Vihuri fighter trainer.
Captain Verkkola used the Bf 109’s low-wing cantilever monoplane configuration as his base for the Pyörremyrsky. The Germans were also willing to supply the Daimler-Benz DB 605A-1 liquid cooled V12 engines and VDM 9-12087 three-bladed light-alloy propellers that were used on the Bf 109 series. It was also installed with a German produced Telefunken FuG 7a model of compact airborne receiver/transmitter.
The main body of the aircraft was built using the vast amounts of wood available to the Finns, with metal being used where absolutely necessary, like the cockpit and engine housing. While many believe the design is similar, if not copied from the Bf 109, there are many differences outside of just the materials used. The rear portion of the fuselage is of wooden monocoque design, with the horizontal stabilizers mounted at the near end, as opposed to the Bf 109’s which are mounted on the vertical stabilizer. The wings were of negative transverse V shape and covered in plywood panelling.
Unlike the wing fuel tanks found in the Bf 109, the Pyörremyrsky had a single tank behind the cockpit, protected by a 10mm thick armoured plate. The landing gear was copied from the Bf 109 but the Finns made some changes to eliminate the narrow and problematic system that plagued the Germans. The tailwheel was also retractable, thus helping it with aerodynamics.
Due to wartime shortages, Finland was forced to rely on substandard replacement products. The use of Lukko glue was one of the main reasons for the failings in the VL Myrsky and so it has been suspected that the Pyörremyrsky would have suffered similar issues to its sister aircraft had it been pushed into service or flown for longer periods of time.
Armament was not fitted to the PM-1 but it was designed to be installed with a Motorkanone mounted 20 mm (.78 in) MG 151/20 cannon and two nose mounted synchronized 12.7 mm LKK-42 machine guns. It was also proposed that the wings would have provisions for two 100kg bombs each for fighter bomber duties, but it is not clear if the proposal was ever considered seriously.
Finland – The VL Pyörremyrsky was intended to be used by the Finnish Air Force.
The PZL P.50 Jastrząb (Hawk) entered development in 1937 as a replacement for the outdated PZL P.11 and PZL P.24 fighters. Very little was known about the aircraft until relatively recently, with only a few photographs and documents about this aircraft surviving World War II. Most of what is known at the time of writing is based on accounts and sketches from PZL engineers years after the war and mostly based on memory, which is not the most reliable form of historiographic evidence. Ultimately, the project was cancelled in March of 1939 due to dissatisfaction with its underpowered radial engine, despite an attempt being made to fit an inline vee engine to the aircraft in the form of the PZL P.56 Kania (Kite).
In the latter half of 1936, plans to replace all of Poland’s PZL P.11 single-engine fighters with the twin-engined PZL P.39 heavy fighter were abandoned, and the need for a maneuverable single-engine interceptor was recognized. Briefly, the PZL P.24 was considered in order to fulfill this role, but as it did not offer much of an improvement over the P.11, it was ultimately decided that an entirely new design was needed.
Wsiewlod Jakimiuk, the head of PZL’s fighter team, submitted a proposal in autumn 1936 featuring “an advanced low-wing monoplane which offered improved all-around performance and great scope for future development” (Cynk, p. 259). The aircraft resembled the American Seversky/Republic fighter designs. One of the things that Jakimiuk focused on in the design of this aircraft was to allow upgrading to larger and more powerful engines to be a simple task to accomplish at any later time.
Ultimately, after a heavily-protracted design process plagued by numerous issues, the aircraft never saw combat and only 32 airframes had been built before Poland was invaded by Germany and the USSR in September 1939, but 30 of these were not completed.
In the fall of 1937, the design, now called the PZL P.50 Jastrząb and powered by a British 840-horsepower Bristol Mercury VIII radial engine, was approved and two prototypes were soon built. The first prototype, called the P.50/I, was designed to take engines up to 1,200-horsepower while the second prototype, the P.50/II, was designed for engines of up to 1,600-horsepower. Both versions were to be armed with four 7.7-millimeter machine-guns in the wings although, confusingly, the few images of the P.50/I show two of these guns in the forward fuselage instead. The P.50A production version of the P.50/I was envisioned to have a top speed of 310 miles per hour (500 kilometers per hour) at 14,100 feet (4,300 meters).
The Polish Aviation Command almost immediately ordered 300 aircraft and paid for the first 100 in advance, with the first 50 expected to be delivered by September 1939. In order to speed up development The Dowty Company of Britain was contracted to build the landing gear for the prototype, while PZL and the Czech Avia company would design the production aircraft’s landing gear. Dowty delivered the landing gear over four months late, and the P.50/I Jastrząb prototype, still utilizing the Mercury engine, did not even fly until February 1939.
During the P.50/I’s initial flight trials, it was discovered that the desired performance parameters were far out of reach. The top speed at full load was only 274 mph (442 kph). It also handled low-speed turns very poorly and had a tendency to wobble at top speed. Curiously, it was discovered that the engine was unable to produce full power under any circumstances. It was not until May that it was realized that the carburettor air intake was too small. After enlarging the intake and improving the tail and wing surfaces, the aircraft’s performance was improved. In August, the aircraft finally reached its desired speed but, by the time the war began in September, the aircraft was still a long way from being ready for service. The only known photos of the P.50/I come from a visit in February 1939 by the Italian Foreign Minister, Count Galeazzo Ciano.
Developed alongside the P.50/I was the P.50/II, which had been completed in the spring of 1939 and was still waiting for an engine by the time of the invasion in September. The P.50/II differed greatly from the P.50/I, so much so that it is believed to have received a new designation just before the war began. The canopy was an all-round-vision hood, somewhat similar to the Soviet Yak-1b. The P.50/II also included provision for additional fuel tanks and a 660-pound (300kg) bomb, and two 20mm cannons were added to the wings. The two machine-guns which were in the fuselage of the P.50/I were also moved to the wings. The powerplant was supposed to be the PZL Waran radial engine, capable of up to 1,400hp, with the intended top speed of the P.50/II being 350mph (560kph). However, development of the engine was far behind schedule and it was estimated that it would not be ready before the middle of 1940. In a desperate search for a suitable engine, several different options were considered. These included the 1,375hp Bristol Hercules and the 1,400hp Gnome-Rhone 14N, again both radial engines. In the end, the Hercules appears to have been chosen, and it was around this time that the P.50/II received its new designation.
There was one more derivative of the P.50, beginning in late 1938. Political upheaval was ongoing in the Polish Air Force high command, and General Ludomil Rayski, who favored radial engines, was coming under heavy criticism and was nearing replacement by General Jozef Zajac, who favored vee engines. This replacement would eventually take place in March 1939. Jakimiuk, the designer of the P.50, anticipated this shift and proposed a Jastrząb adapted to take an inline engine. The aircraft was given the designation P.56 Kania (Kite) and was to be powered by the 1,200hp Hispano-Suiza 12Y, and later by the improved 1,600hp Hispano-Suiza 12Z. However, another PZL designer, Jerzy Dabrowski, submitted a competing design bearing the designation P.62, and this design was preferred over the P.56. The P.56 was ultimately cancelled in the summer of 1939.
When General Rayski was ousted from the command of the Polish Air Force in March 1939, the P.50/I was still having severe problems. His replacement, General Zajac, canceled all production of the P.50 almost immediately. 30 P.50A airframes had begun construction at the W.P.1 plant in Okecie and, after the P.50/I began to show improvement, construction was permitted to continue on these aircraft only. Because of the unsatisfactory results of the Mercury engine, plans were made to power the very first of these production aircraft with the 870hp Gnome-Rhone 14Kirs, and this aircraft was very close to being ready in September 1939. This was to be a sort of test aircraft for an improved version of the P.50A, the P.50B Jastrząb B. There were also plans to mount the 1,100hp Gnome-Rhone 14K or the 1,000hp Pratt & Whitney R-1830 Twin Wasp, although these never came to fruition.
“The Hawk Which Would Never Prey”
On September 5th, 1939, the PZL factory in Warsaw was evacuated. Test pilot Jerzy Widawski attempted to escape with the P.50/I prototype, but was accidentally shot down by Polish anti-aircraft guns. Five pre-production P.50A airframes and the P.50/II prototype, including the aircraft intended to be equipped with the 870hp engine mentioned earlier, were moved out of the Okecie plant on September 3rd. These were captured by the Germans and scrapped in 1940, bringing a final end to the P.50 Jastrząb project.
PZL P.50/I Jastrząb – Initial prototype of the PZL P.50 series. Powered by an 840hp Mercury VIII engine, the top speed was intended to be 310 mph, but it only ever reached 275 mph. Armament was four 7.7mm machine-guns, with two in the forward fuselage and two in the wings. One produced, first flew in February 1939.
PZL P.50A Jastrząb A – Planned production version of the PZL P.50/I. 300 were ordered, but only 30 built, all incomplete by the time of Polish capitulation. Fuselage was changed to a razorback rear, akin to the American P-47. It is unclear whether the fuselage machine-guns were moved to the wing, as documents imply they were but sketches of the aircraft still show them in the fuselage. Top speed had been improved to 310 mph (500kph).
PZL P.50B Jastrząb B – Planned development of the P.50A with a more powerful radial engine. One P.50A was planned to fit an 870hp Gnome-Rhone 14Kirs engine as a sort of testbed for the P.50B, but that is all that is known about this variant.
PZL P.50/II Jastrząb II – Second prototype developed alongside the P.50/I prototype as an all-around upgraded version. The canopy was changed. A 660 lbs (300 kg) bomb was added, along with two 20mm cannon to the wings. The engine was upgraded to the 1,400hp PZL Waran engine, giving a projected top speed of 350 mph (560 kph) . Only one was produced, without the engine, and never flew.
PZL P.56 Kania – Planned development of the P.50A Jastrząb A using either a 1,200hp Hispano-Suiza 12Y or 1,600hp Hispano-Suiza 12Z inline Vee engine. None produced.
Poland – 300 copies of the P.50A type were ordered, with only 30 incomplete airframes + 1 P.50/I prototype produced. Did not see service. A single P.50/II prototype also existed, but the type was never ordered.
PZL P.50A Jastrząb A Specifications
31 ft 9.875 in / 9.7 m
25 ft 3.125 in / 7.7 m
8 ft 10.25 in / 2.7 m
208.83 ft² / 19.4 m²
One 840hp (648.8kW) Bristol Mercury VIII nine-cylinder radial engine
3,748 lbs / 1,700 kg
Maximum Takeoff Weight
5,511 lbs / 2,500 kg
310.6 mph / 500 kmh
466 mi / 750 km
Maximum Service Ceiling
14,107 ft / 4,300 m
Four 7.7mm KM Wz 36 machine-guns mounted in the wings OR two in the fuselage and two in the wings
Provision for an unknown weight of bombs, possibly 220.5lbs (100kg), to replace two wing machine-guns
Polish aircraft historian Zabytki Nieva discusses the PZL P.50. Audio is in Polish with English subtitles available.
Video made by the author specifically to accompany this article.
People’s Republic of China (1945-1952) Fighter – 8+ Operated
Widely known as one of Japan’s most iconic aircraft of the Pacific War, the Nakajima Ki-43 Hayabusa’s service life was not limited to the Second World War. Shortly after the Japanese capitulation, Nationalist and Communist Chinese forces were able to capture stockpiles of firearms, tanks and planes left over by the fleeing Japanese forces. Among these were various models of the Nakajima Ki-43 Hayabusa. These were pressed into service with the Communist Chinese as an advanced combat trainer and fighter. One of the rather obscure chapters of the Hayabusa’s service life was that it was the first plane used by the Communist Chinese in aerial combat.
Developed in the late 1930s, the Nakajima Ki-43 Hayabusa (Type 1 Fighter) enjoyed a relatively successful service record in the Second Sino-Japanese War once introduced in 1941. The Japanese 59th and 64th Sentai (Squadrons) were the first two squadrons to receive the new Ki-43-I fighter. With barely any resistance by the Republic of China Air Force (ROCAF), the Ki-43-I helped reinforce Japanese aerial superiority over China, French Indochina, Malaya, and parts of India until the arrival of lend-lease Allied warplanes for China. Throughout the service of the Hayabusa, three major variants were issued to units: the Ki-43-I, Ki-43-II, and Ki-43-III. The Japanese also provided some of these variants to the Manchukuo Imperial Air Force in the Northeast region of China. With the end of the Second Sino-Japanese War, stockpiles of Japanese equipment was up for grabs between the Soviets, Nationalist Chinese, and the Communist Chinese. The Nationalist Chinese forces reoccupied Shanghai near the end of 1945 and captured warplanes formerly belonging to the Japanese. Among these were various models of the Hayabusa which were used to equip the 18th and 19th Squadrons of the ROCAF’s 6th Fighter Group. These Hayabusas were stationed at Shandong in preparation for the Chinese Civil War. Due to a lack of spare parts and adequate mechanics, the two squadrons were disbanded the following May.
The Communist Chinese forces were by no means idle during the immediate few postwar months. Countless guns were captured, with a considerable amount of tanks and planes as well. In October of 1945, the Communist Chinese forces captured their first five Hayabusas during the liberation of Shenyang during the Liaoshen Campaign from the Nationalists. These five captured Nationalist Hayabusas were Ki-43-II models that formerly belonged to the Japanese 4th Training Regiment. The exact model of the planes is unknown. (It is unknown if they are kō, otsu, hei, etc. variants). These five planes would be sent to the recently established Northeast Old Aviation School (东北老航校) after some refurbishing and repairs. In December of the same year, two of these planes were repaired and were planned to be ferried to the Northeast Old Aviation School. Two Japanese ferry pilots now loyal to the Communist Chinese took off from Fengjibao (奉集堡) to fly to Tonghua (通化), one of their destinations. The two Hayabusas and their pilots never made it to Tonghua however, and it is widely speculated that these Japanese pilots were unfamiliar with the geography and ended up getting lost. This is indeed a possibility but there are many other theories. It’s conceivable that the planes suffered from mechanical failure and crashed. Another possibility may be that the pilots were intercepted by ROCAF planes, but there is no proof of this.
The rest of the Hayabusas were eventually delivered to the Northeast Old Aviation School, where they were used as advanced trainers for fighter pilots. In April of 1948, men belonging to the Northeast Old Aviation school were able to capture an unspecified amount of Hayabusa fighters in the Chaoyang (朝阳镇) Town airport located in Jilin. This was followed by another unspecified batch of Hayabusas captured in Sunjia (孙家) Airport located near Harbin in the Heilongjiang province sometime in June of the same year. Four Hayabusas were recorded to have been repaired by the school from 1947 to 1948. Under the guidance of former Japanese and Manchukuo pilots, many of the Communist Chinese air cadets were soon able to graduate from flying in the two-seater Tachikawa Ki-55 trainer to flying solo in the Hayabusa.
In March of 1948, a number of experienced pilots and instructors were pulled from the school to form a “Combat Flying Wing” (战斗飞行大队). The 1st Squadron would use bombers and transport aircraft while 2nd Squadron would use fighters. Among these would be six Ki-43-II models. The intent of this formation was to combat Nationalist planes, but this wing never saw any combat action.
Considerations were made to use the Hayabusa in the Establishment of the People’s Republic of China parade on October 1st of 1949, but this did not happen. Despite what one may think, the Japanese planes were not withheld from the parade due to political and racial issues, but rather fear of them experiencing mechanical problems during the parade.
As such, these worn out Hayabusas were grounded. By November of 1949, there were only five examples of the Hayabusa that were still in use. These final five fighters were used by the 7th Aviation School as trainers and teaching aids. By 1952, all of the Hayabusas were finally retired from service. There are no surviving examples of the Communist Chinese Hayabusa, but there is one known photo of the Communist Hayabusa in service.
First Air-to Air Combat of the Communist Chinese Air Force
In the afternoon of October 15th 1947, four Nationalist Chinese P-51D Mustangs belonging to the Shenyang Beiling airfield took off under the leadership of Xu Jizhen (徐吉骧), the co-captain of the squadron. They were tasked with the mission of patrolling the airspace of Harbin (哈尔滨), Jiamusi (佳木斯) and the Sino-Soviet border. Upon crossing the mountains near Mishan (密山), the Mustangs squadron noticed a Tachikawa Ki-55 trainer with Communist Chinese markings belonging to the Northeast Old Aviation School preparing to land at the nearby Tangyuan (汤原) airport. This Ki-55 was piloted by Lu Liping (吕黎平) and an unnamed Japanese instructor. Xu Jizhen immediately dove for the trainer and began firing. The area immediately behind the instructor’s compartment was hit, which resulted in a fire. Watching the attack from the ground, Fang Hua (方华), a veteran Communist soldier, scrambled for a nearby parked Nakajima Ki-43-II Hayabusa and took off. Unfortunately for him, the Hayabusa was not loaded with ammunition so he was unable to engage the Mustangs. However, he was able to lead the Mustangs away from the airfield and evaded their shots until they ran out of ammo. This unfortunate skirmish was the first air-to-air combat experience the Communist Chinese had.
Debunking the Numbers Operated
According to many Western sources, the Communist Chinese Forces only operated five Hayabusas. This is however incorrect. The author believes the reason that these sources mention only five models captured was due to translation errors or simply by overlooking facts. The most likely cause of the misconception is likely due to two facts:
By the end of the Liaoshen Campaign, the Communist Chinese forces had captured five models.
By the time the PLAAF was officially established, there were five models still in service.
What these Western sources may have overlooked however, was the fact that two of the first five models captured crashed during a ferry flight in December of 1945. This leaves only three models operational.
However, a commonly overlooked fact is that the Northeast Old Aviation School was able to capture an unspecified amount of Hayabusas in the Chaoyang (朝阳镇) Town airport located in Jilin sometime in April of 1946. Another unspecified batch of Hayabusas were also captured in Sunjia (孙家) Airport located near Harbin in the Heilongjiang province in June. Due to the unspecified nature of the amount of Hayabusas captured in these two places, it only adds to the difficulty of determining how much Hayabusas were truly captured and operated. But on an inventory check done in April of 1948, a total of six Hayabusas were accounted for serving with the 2nd Squadron. According to this record, that should mean three or more Hayabusas were captured in those two airfields. That should make a total of eight or more Hayabusas when accounting for the two crashed ones. In conclusion, the author believes that a potential total of eight or more Hayabusas were captured, and operated by the Communist Chinese forces to some extent until the retirement of all models in 1952.
Gang, W., Ming, C. Y., & Wei, Z. (2012). 中国飞机全书 (Vol. 1). Beijing: 航空工业出版社., Gang, W., Ming, C. Y., & Wei, Z. (2009). 中国飞机全书 (Vol. 2). Beijing: 航空工业出版社., Allen, K. (n.d.). PEOPLE’S LIBERATION ARMY AIR FORCE ORGANIZATION., 网易军事. (2016, May 24). 老航校70周年：“鬼子飞行员”在中国当教官., Zhang, X. (2003). Red Wings over the Yalu: China, the Soviet Union, and the Air War in Korea. College Station: Texas A & M University Press., Side Profile Views by Brendan Matsuyama
The VL Myrsky (translates as Storm) is a Finnish domestically produced fighter. 51 were manufactured between 1941 and 1945 and it was one of the fastest aircraft in the Finnish inventory at the time. Despite having good performance on paper, it was plagued with issues and uncertainty. It would be withdrawn from service in 1947 having served in numerous roles such as interceptor, fighter-bomber and reconnaissance.
Finland, being a small and newly independent nation, suffered from severe financial limitations and this included funds allocated towards its air force. However, the situation in 1930s Europe was not looking promising and in 1937 major funds were allocated to the defence budget for modernisation and expansion of Finland’s armed forces. By 1938, Finland had bought 7 Fokker D.XXI fighters, as well as the manufacturing license to produce more. However, Head of the Defence Council, Marshal Mannerheim, highlighted the need to produce a local fighter in order to lessen reliance upon foreigners in case of war. Major General Jarl Lundqvist, commander of the Finnish Air Force, replied that alternatives were being sought out but that high prices of specialised machinery, as well as many nations gearing up for war themselves, needed to produce such aircraft put limitations in place.
In early 1939, the Air Force made a survey of various aircraft designs and, upon completion in April, invited the State Aircraft Factory (Valtion lentokonetehdas) to ‘negotiations in Tampere on the construction of a prototype of a fighter machine in Finland’. On 4th May 1939, VL presented 5 different designs using the Bristol Taurus engine to the Ministry of Defence (puolustusministeriö) .
The Ministry of Defence placed contract 1094/39 with the State Aircraft Factory on 8th June 1939, which called for 33 aircraft to equip a fourth squadron. The design chosen was to be powered by the Bristol Taurus III 14-cylinder two-row radial aircraft engine, have semi-elliptical 19 square meter wings and retractable landing gear with allowances for ski pods. Its initial appearance was similar to the VL Pyry trainer which was undergoing prototype trials at the time.
However, when the United Kingdom declared war upon Germany in September 1939 due to its invasion of Poland, the possibility of acquiring the Bristol Taurus disappeared and a solution was needed. The design team thought the best replacement was the Pratt & Whitney R-1830-S3C3-G Twin Wasp and an order was placed. Due to the inevitable delays and mounting pressure in Europe, the Air Force placed an order for 35 Fiat G.50s to equip the fourth squadron. On 30th November 1939, Soviet forces attacked Finland in the opening moves of what would become known as the Winter War. This action put paid to many of Finland’s rearmament plans, including the Myrsky development, with an official order of termination being issued by the Ministry of Defence on 8th December (which seems to have not been fully complied with due to archival material showing dates during the Winter War).
After the conclusion of the Winter War on 13th March 1940, Finland saw itself in a critical situation which was further enhanced by the actions of Germany in Denmark and Norway. In April, the Finnish domestic programme was restarted with an emphasis upon speed, which led to more delays on the design. Finland reached out to both the US and Germany for more powerful engines, like the American Pratt & Whitney R-2800 Double Wasp and German BMW 801. However, the US put an export ban on war material in July and Germany was unwilling to sell any materials except captured ones like the Curtis 75A Hawk and Morane Saulnier MS 406. This then led to the placement of the programme in suspension until the winter of 1940.
On 20th December 1940, contract 1621/40 was issued ordering a prototype. About 60,000 hours went into the design phase, with 77,000 manhours going into the manufacture of the prototype. The original goal was for a working prototype to be completed in early July 1941 but, with the outbreak of the Continuation War, the project saw delays again. The prototype was finally completed in December and made its maiden flight on the 23rd December 1941 by Lieutenant (Luutnantti) Erkki Itävuori. A few redesigns were made during this second stage of development, the most notable being the copying of the tailplane of the Brewster Buffalo F2A. Given the serial MY-1, the prototype suffered from engine difficulties, as well as displaying a tendency to yaw. Also, it had a high wing loading (194 kg/m2) which meant that its rate of climb and maneuverability were compromised.
The MY-1 was redesigned and modified in order to fix the issues highlighted in the small scale test flights. The yaw was resolved by redesigning the whole rudder with an enlarged area and removing the supports from the horizontal stabilizers. Weight was reduced by changing the fuel tank, changing the engine gills and a few other minor changes, freeing up 317 kg and decreasing the wing loading to 175 kg/m2. The Hamilton Standard propeller was replaced by a locally designed VLS 8002 adjustable propeller and the exhaust pipes were modified to attain better thrust. Overall the MY-1 prototype went through four major modification stages and attained a final maximum speed of 519 km/h at 3250 meters altitude and a climb to 5000 metres in 6.5 minutes. While not perfect, the aircraft was seen as satisfactory. MY-1 took its last flight on 26th November 1943 with Captain (Kapteeni) Kokko, ending with a total logged time of 142 hours and 20 minutes in 162 flights.
Before the prototype’s test flights had all finished the Air Force placed an order for a pre-series of three aircraft to be produced on 30th May 1942. The idea was for these three aircraft to help test concepts and make mass production faster when the time came. These craft were serialled MY-2 to MY-4 respectively. MY-2 was completed in April 1943, it had thinner wings, Hamilton Standard metal propeller, pneumatic brakes and was the lightest Myrsky at 2150kg empty. It was destroyed on 6th ofMay 1943 when its engine failed from lack of fuel, Captain P.E. Sovelius was injured during the crash landing. MY-4 was finished 5th June, it boasted a thicker wing, easier removable engine, better cowlings, hydraulic brakes and the VLS 8002 adjustable propeller. It weighed in at 90 kg more than the MY-2, or 2 240 kg. MY-3 was completed on the 11th July, it weighed in at weighed 2 210 kg but was similar to the MY-2 except for slight modifications. This series was known officially as the I Series (I Sarja).
MY-3 made a belly landing on 5th August 1943 as the landing gear malfunctioned. During the repairs, they patched up the fuselage with plywood, adding another 10 kgs. Splines were added to the propeller spinner to help reduce overheating and these were carried over to the production models. After repairs the MY-3 was cleared for more flights, on 19th November 1943, during a test dive, aeroelastic flutter broke off the wings and then the tail, plunging the aircraft into the ground at 855 km / h. Warrant Officer (Vääpeli) Aarre Siltavuori was killed. Investigation after the event concluded that the wings needed to be reinforced and that dive speeds should not exceed 600 km/h.
MY-4 was continually used for testing and its armament layout was the one used in the production series. In February 1944 it was issued to No. 26 Fighter Squadron (Hävittäjälentolaivue 26) to assess its viability as a combat aircraft, it immediately caused problems as the 20 pilots who took turns to fly it noticed issues with its flying characteristics in comparison to their Fiat G.50s. On the 17th March, during a diving test the plane was attempting to spin to the right and lieutenant Jaakko Marttila struggled with the aircraft, under such stress the right wing finally broke at two metres from the tip, causing the plane to enter into an uncontrollable spinning dive that killed the pilot.
Production Series and the Continuation War
On the 18th August 1942, contract 1952/42 was issued that specified a production of 50 Myrskys, split into two batches. A three aircraft pre-series, as covered above, and a production series, to be called the II series, of 47 aircraft to be serialized as MY-5 to MY-51. MY-5 was completed in December 1943 and MY-51 was finished in December 1944.
The Myrsky continued to show problems during dives, MY-6 crashing due to the left elevator breaking loose when it reached 640 km/h in June 1944. This caused an order to reinforce all elevators, both on completed models and those going through production. Due to the numerous delays, the now adequate performance, as well as the many Bf 109’s supplied by Germany, the Fighter squadrons were not interested in the Myrsky. Indeed, only No. 26 Squadron were equipped with Myrskys to replace their aging Fiat G.50s but these were soon replaced by Brewster F2A Buffalo s. Orders from Air Force command saw the Myrsky banned from crossing the front lines due to their poor performance against contemporary Soviet fighters. Instead the reconnaissance squadrons (Tiedustelulentolaivue) gratefully received these speedy and modern aircraft, by comparison to their previous machines. No. 12 Reconnaissance Squadron became the first Myrsky reconnaissance unit in July 1944, there first mission was on the 9th August with a patrol flight in the Suistamo area where they attempted to intercept a flight of Yak-7 fighters with no results. The 22nd August saw the Myrskys baptism of fire when a 6 plane reconnaissance mission came across 3 Yak-9s at Mantsi. Lieutenant Linden scored confirmed hits upon one Yak but failed to bring it down, during the return flight Captain Virkkunen scored hits upon a La-5 but still not confirmed kills (after the war it was confirmed the Yak made an emergency landing at its home base and the La-5 suffered from damaged pressure systems).
During the later design phase, it was decided that the planes should be able to mount two 100 kg bombs. Pilots at the Tampere testing facility practiced the concept using weight concrete bricks but due to the planes relegation to reconnaissance, it was believed that the racks would not be used. However on the 3rd September, Captain Oiva Tylli led a six plane formation to bomb the Soviet 7th Army Corps headquarters at Orusjärvi (this saw the lifting of the crossing frontlines orders, as the HQ was some 35-40km behind the Soviet lines). 11 of the 12 bombs detached from their racks and damaged the lightly defended headquarters and the planes flew out of there before they could be intercepted. Later that same day the last combat mission of the Mysrky during the Continuation War took place, a four Myrsky flight was sent on a patrol at Sortavalan-Lahdenpohja but returned empty handed.
On the 4th September 1944 a ceasefire came into effect as a result of negotiations between the Finnish and Soviet Governments. No. 12 Reconnaissance Squadron was ordered to fly to Joroinen and await further orders. At the closing of hostilities, 44 of the 47 II series aircraft were completed. One squadron, No.12, was fully equipped, and another squadron, No.16, was partially equipped with six.
Lapland War and Peace
One of the stipulations of the ceasefire was the cessation of diplomatic relations with Nazi Germany and the expelling of Wehrmacht forces from Finnish territory by the 15th September 1944. With over 200,000 troops residing in Finland, as well as the essential nickel mines in Lapland, the Germans were both incapable and unwilling to withdraw in such a quick manner. This led to the outbreak of what became termed ‘The Lapland War’ (Lapin Sota).
A Finnish force of some 75,000 (4 Divisions as well as some attached elements) was assigned to the task of pushing the Germans from their land. A special air detachment was formed, Lentoryhmä Sarko, with the mission to support ground operations. 2nd flight of No. 12 Reconnaissance Squadron was subordinated to No. 26 Fighter Squadron at Kemi. Soon Myrskys were performing reconnaissance missions over Lapland but the severe weather soon put paid to any more flights by the Myrskys and on the 23rd November the last flight in combat conditions by a Myrsky was completed.
After the formalisation of the Moscow Armistice in September 1944, the Air Force was put in to peacetime strength in December. This saw a major reduction and restructuring of the Air Force as a whole. No.12 Reconnaissance Squadron became No.11 Fighter Squadron, and No.16 Reconnaissance Squadron became No.13 Fighter Squadron, these squadrons were amalgamations of other units and so were also equipped with BF-109G-2s and Curtiss Hawk 75As. The Myrskys continued to serve in these fighter units but were still subject to accidents, especially from stalling, which saw a suggestion to modified the wings with slots. MY-50, which was never issued to the air force but remained at the factory’s hanger, was modified with slotted wings but nothing went further. On 9th May 1947, Captain Kauko Ikonen, took MY-28 out for a training flight when it suddenly entered into a dive and broke up in the air. The plane plunged into the soft clay and was not recovered, No.11’s commander ordered a grounding of the entire Mysky fleet, which was confirmed by the Wing’s headquarters later that day.
The last flight of the Myrsky took place on 10th February 1948, when MY-50, was allowed to fly from its test hanger to Tampere for storage but as it came into land, it overshot the runway and landed on its belly.
Today there is a restoration project to bring back MY-14 to a fully reconditions state for display at the Finnish Aviation Museum. The project has reach a stage where it could be unveiled to the public for Finnish Air Force 100th anniversary air show in June 2018.
When the original order went out for the design, Arvo Ylinen (head of the design-bureau), Martti Vainio (aerodynamics), and Torsti Verkkola (structural design), were assigned the task of designing the new plane.
They decided to combined the learning they had from the Pyry trainer with the experience of licensed building of modern aircraft like the Fokker D.XXI. This allowed for not only cheaper design and production but also allowed for the design to be tweaked to Finnish desires. Due to the limitations upon Finnish industry (both due to its economic and geographical locations), it was decided that the design would be a combination of wood and metal.
The fuselage used a metal wire frame which was then covered with fabric and plywood, while the wings made from plywood and covered in a birch veneer (called Kolupuu).This did allow for cheaper production and lighter construction but contributed to the breaking of the wings upon reaching certain speeds. Because of the rarity of duraluminium, it was decided that the Myrsky should have none of it in its construction (but because of problems finding a suitable replacement, it was used in certain aspects of the machine like the flaps), instead aluminum (which had been bought from Norway and Sweden before the war) would be used sparingly and combined with specialised wooden parts.
The generalised design was the conventional piston aircraft, with a low wing attached just forward of center. The cockpit suffered from the same issues that many of its contemporaries did, in that the long nose limited its forward vision, but it is have excellent side visibility. The armament was four VKT 12,70 mm LKk/42 machine guns, mounted two per side of the engine, these were synchronised to fire through the propeller. It was also decided to add a hard point under each wing which would allow for an additional fuel tank or a 100kg bomb to be used.
Due to wartime shortages, Finland was forced to rely on substandard, replacement products. The use of Lukko glue was one of the main reasons for the failings in the Myrsky. It was not of the same quality as pre-war glue and did not stand up to rain, frost and humidity (a common occurrence in Finland), and would require more man hours to keep the aircraft in a flyable condition.
During its lifespan, the Myrsky was involved in 48 separate incidents, 10 of these resulted in the complete loss of the aircraft and 4 pilots died as a result.
MY-2 was destroyed on 6th May 1943 when its engine failed from lack of fuel, Captain P.E. Sovelius was injured during the crash landing.
MY-3 was destroyed on 19th November 1943 when aeroelastic flutter broke the wings of the aircraft. The Pilot, Warrant Officer Aarre Siltavuori was killed
MY-4 was lost on 17th March 1944 during a training flight. The plane entered into a dive which then broke one of the wings. Lieutenant Jaakko Marttila died in the crash.
MY-29 was destroyed on 4th September 1944 during a transfer flight. Lieutenant Aulis Kurje lost control of his aircraft when the engine overheated and cut out. The plane crashed into the wood, causing the seat to break free, killing the pilot.
MY-25 was destroyed on 13th November, 1944. During a reconnaissance flight near Kemi, MY-25s engine cut out forcing Lieutenant Berndt Schultze to perform a crash landing, he sustained minor injuries.
MY-27 was destroyed on 26th January 1945. After a crash landing on the 23rd January 1945, it was decided to fly the aircraft down to Pori, during the flight the fuel ran out. Warrant Officer N. Satomaa crashed the plane into a forest near Veteli. He was badly wounded but survived.
The MY-26 was destroyed 25th December, 1945. Due to malfunction, Staff Sergeant (Ylikersantti) E. Tähtö was forced to crash land in Pori. He walked away with minor injuries.
MY-24 was destroyed on 11th December 1945. Sergeant (Kersantti) Onni Kuuluvainen lost control of his craft when performing a speed correction. After several attempts to recover the plane he parachuted to safety. The plane crashed into a farmer’s field in the Pori area.
MY-5 was destroyed on November 20th, 1946. Lance corporal (Korpraali) Erkki Jaakkola was forced to make a crash landing in a field after his plane suffered from a fuel feeding problem after climbing to 7,000 metres.
MY-28 was destroyed on 9th May, 1947. During a training session, Captain Kauko Ikonen lost control of his plane, which then broke into pieces and smashed into the ground at Nakkila. This caused the entire Myrsky fleet to be grounded.
VL Myrsky – Myrsky prototype. Serialled MY-1. It differed from the later versions in being armed with two fuselage mounted 12,7mm mgs and four wing mounted 7,7mm mgs in the wings. It also had the Pratt & Whitney R-1830-S3C3-G Twin Wasp engine. The altitude stabilizers were originally supported but removed during the stage III modifications. Its undercarriage is also 15cm longer, giving it a more angled appearance when on a flat surface. Only 1 produced
VL Myrsky I – The pre-series production. Used to test ideas from the prototype, and to help gain experience in production. Each one was slightly different with various modifications. These were powered with the Pratt & Whitney R-1830-SC3-G Twin Wasp engine. They had more fabric pieces than their production counterparts. 3 produced.
VL Myrsky II – The production series. Taking the experience gained in the prototype and pre-series phases and putting it into practice. Using the R-1830-SC3-G Twin Wasp engine, it was modified with different gears to produce 1,155 horsepower on take-off. 47 were built.
VL Myrsky III – In March 1944 an order for 10 improved Myrsky versions was given to the State Aircraft Factory. This order was cancelled on 30th September 1944 and the whole series was cancelled on 30th May 1945.
The VL Myrsky was the embodiment of Finnish thinking, small and quick, hard hitting but light. The domestic fighter programme would not only bring more jobs to the locals but would be a point of pride that Finland could stand its own if it needs be. Also, as it was the only domestic fighter to see service during the war, it became a symbol of pride of Finnish independence.
Because of the many delays in its production, by the time it arrived on the front lines, the war had stabilized into what is termed ‘asemasota kausi,’ or The Trench War period. This meant that the war was much quieter in comparison to the other fronts that the Soviets were fighting on. The fighter pilots reports upon its mediocre performance in terms of speed and maneuverability in comparison to the Yaks and Las they were facing but the reconnaissance pilots reported positively upon these characteristics. It occupied the second fastest serving aircraft in the Finnish Air Force (only the BF-109 being faster) and its cockpit ergonomics were favorable and the pilots enjoyed its ground handling properties, thanks to the wide undercarriage.
It was far from the perfect aircraft, at low speeds it had a tendency to stall to the left. Its batteries tended to drain quickly if not pulled from the aircraft when not in use and the metal parts were prone to rusting. The inferior quality of the glue used during the war meant that more maintenance was required to keep the airframe flight worthy, reports of seams on the wing surfaces, rudder and elevators opening were a common occurrence. Pilots, both fighter and reconnaissance, reported upon the armament being too weak to take on the modern Soviet fighters and that due to the engine being governed, the plane was ‘too slow’ for what it should have been.
Finland – The VL Myrsky was only used by the Finnish Air Force
VL Myrsky II
36.08 ft / 11.00 m
27.39 ft / 8.35 m
9.84 ft / 3.00 m
193.75 ft² / 18.00 m²
1x Pratt & Whitney R-1830-SC3-G Twin Wasp modified (1,155 hp)
7,083 lbs / 3,213 kg
5,152 lbs / 2,337 kg
49.21 ft/s / 15.00 m/s
292.04 mph / 470 km/h at Sea Level
332.43 mph / 535 km/h at 10830 ft / 3,300 m
Maximum Service Ceiling
31,170 ft / 9,500 m
4x 12.7mm VKT 12,70 Lkk/42 (960 Rounds Total)
2x 220.5 lb /100 kg Bombs or
2x 39.62 Gal / 150 L Drop Tank
The Hakaristi (Finnish Swastika)
It is important to note the use of the ‘Swastika’ on Finnish military equipment due to the confusion of its application.
Finland first adopted the Swastika (known as Hakaristi, broken cross, in Finnish) on the 18th March 1918, thanks to a donated aircraft that arrived earlier that month from Swedish Count Eric von Rosen (who used a blue swastika as his personal symbol). The Hakaristi became a national symbol from that moment, being used on everything from the Medal of the War of Liberation, the Mannerheim Cross, tanks, aircraft, to even a Women’s auxiliary organisation.
It became part of the official Air Force insignia, being used as an identification symbol as well as on certain badges and awards, from its inception in 1918 and today is still maintained upon certain symbols like the Standards of Commands.
Due to this early adoption, it has no association with the Nazi regime and the usage of such a symbol by both parties is only a coincidence.
People’s Republic of China (1948-1953) Fighter – 39 Operated
The North American P-51 Mustang is considered one of the world’s most iconic warplanes from the Second World War, seeing action in nearly all theaters, as well as the Korean War and many other conflicts thereafter. However, one of the lesser known stories of the Mustang is its service with the Communist Chinese forces who would go on to form the People’s Republic of China shortly after. A total of 39 Mustangs were obtained from the Chinese Nationalist forces either by capture or defection. These Mustangs were used in various roles with the Communists, and nine of them even had the honor of flying over Beijing on October 1st 1949 for a parade to commemorate the establishment of the People’s Republic of China. Although never seeing combat, the Mustangs still had served with the Communist Chinese forces as one of their most advanced fighters until the arrival of Soviet aid.
The Republic of China (i.e, Chinese Nationalists under Generalissimo Chiang Kai-shek) was a notable operator of the North American P-51 Mustang during the Second Sino-Japanese War (1937-1945). Since the United States entered the Second World War, plans were made to provide the Republic of China China with modern American warplanes to replace the worn and outdated planes that the Republic of China Air Force (ROCAF) were using. The Mustangs were initially flown by pilots of the Chinese-American Composite Wing (CACW) starting from November 1944. The models they operated were P-51B and P-51C, but later in February 1945, P-51D and P-51K variants were delivered and put to use against the Japanese along with the P-51B and P-51C. At the end of the Second World War, the ROCAF received 278 Mustangs from the USAAF, most of which were P-51D and P-51K models, but also with some F-6D and F-6K photo reconnaissance models. Soon after, the uneasy relationship between the Communist Party of China under the leadership of Mao Zedong and the Nationalist government under the leadership of Jiang Jieshi (Chiang Kai-shek) disintegrated. As such, the civil war between the two parties resumed after nearly nine years of truce. This time however, the Communist forces were more prepared to fight the Nationalist forces. As time went on, the Nationalist forces began losing their hold on mainland China and were forced to retreat to Formosa (Taiwan), but not before many of their soldiers, officers and generals defected, leaving a substantial amount of equipment behind.
The People’s Liberation Army obtained their first Mustang on September 23rd 1948 when Captain Yang Peiguang (杨培光) from the Nationalist 4th Fighter Wing based in Beiping (Beijing) defected with his P-51D to the Communist forces at Siping, Jilin Province. The bulk of the Mustangs which would be captured by the Communist forces were, however, from the Liaoshen Campaign which lasted from September 12th – November 2nd, 1948. With the Communist victory at the Battle of Jinzhou on October 15th, a considerable amount of Nationalist equipment was captured; among these were thirty one Mustangs in various states of repair at the Jinzhou Airfield. Though now with thirty four Mustangs in total, the People’s Liberation Army was not able to press any into service due to many factors; the most important two being the lack of able pilots and the varying states of disrepair that the Mustangs were in.
The city of Shenyang was finally captured by the People’s Liberation Army on October 30th 1948, and on the second day of the city’s capture on October 31st, the Northeast People’s Liberation Army Aviation School sent men to secure the Shenyang Beiling airport, factories, warehouses, personnel, and various other assets formerly belonging to the Nationalists. In November, the Shenyang Beiling airport was officially established as the People’s Liberation Army Air Force Repair Factory Number 5 (中国人民解放军空军第五修理厂). With the establishment of this repair factory, the first machines to be repaired were the Mustangs. The repairs took top priority and the first Mustang was ready for service on December 30th. Since then, thirty six Mustangs were repaired within a span of eighteen to twenty months lasting until 1950.
On December 10th 1948, the People’s Liberation Army was able to capture the Nationalist-held Beiping (Beijing) Nanyuan Airport as part of the Pingjin Campaign. Three Mustangs were found in relatively good condition, and a total of 128 Packard-built V-1650 Merlin engines were captured as well. This boosted the total amount of Mustangs in the People’s Liberation Army to thirty seven, and provided plenty of replacement engines for maintenance. After this, two more Mustangs would fall in the hands of the Communist forces.
On December 29th, Lieutenant Tan Hanzhou (谭汉洲) of the Nationalist 4th Fighter Group defected with his Mustang from Qingdao to Communist held Shenyang. The last Mustang to fall into the People’s Liberation Army’s hands occured on January 14th of 1949 when Lieutenant Yan Chengyin* (阎承荫) from the Nationalist 3rd Fighter Group’s 28th Squadron defected from his home base of Nanjing to Communist held Jinan.
Now with thirty nine Mustangs in total, the People’s Liberation Army began to put them to use. Starting from late January 1949, a large number of Mustangs were presented to the Northeast Old Aviation School’s (东北老航校) 2nd Squadron of the 1st Air Group with the purpose of training pilots. On August 15th 1949, the People’s Liberation Army formed their first flying squadron named at the Beiping Nanyuan airfield. The squadron consisted of two Fairchild PT-19 trainers, two de Havilland Mosquito fighter-bombers and six Mustangs. Shortly after the formation on September 5th, this squadron was assigned the task of defending Beiping’s airspace from Nationalist forces. At some point before October, eleven more Mustangs were assigned to this squadron. The squadron saw no combat.
* Mr. Yan later changed his name to Yan Lei (阎磊) after his defection.
Perhaps the most notable use of the Mustangs in Communist Chinese service was on October 1st 1949. By then, the bulk of the Nationalist forces were in discord and in the process of retreating to Formosa (Taiwan). With the Communist victory inevitable, Mao Zedong proclaimed the establishment of the People’s Republic of China. A Soviet-style military parade was held in newly-renamed Beijing’s (Beiping) Tiananmen Square which included sixteen thousand and four hundred soldiers, one hundred and fifty two tanks, two hundred and twenty two cars and seventeen planes were displayed to the public. Of these seventeen planes, nine were Mustangs. The Mustangs flew in groups of threes in a V formation and led the aerial convoy. Once over Tiananmen square, these Mustangs increased their speed and flew past the square and out of sight, they made a turn and reentered Tiananmen square for the back just in time to link up with the two Fairchild PT-19A trainers flying last. Because they re-entered the square so quickly, the spectators were led to believe these were nine different Mustangs, with a total of twenty six planes appearing over Tiananmen square instead of the actual seventeen. This was mentioned in a government made propaganda newsreel. Of these nine Mustangs, at least one was a P-51K model.
After the parade, the Mustangs were once again deployed in a defensive state awaiting possible Nationalist intrusions in Beijing. By November 1949, the People’s Liberation Army Air Force was officially established and a total of twenty two airworthy Mustangs were in service, with nine more awaiting repair. This meant that thirty one Mustangs still survived, with eight written off. It is unknown what precisely happened to these Mustangs but the author speculates that they could have been cannibalized for parts, destroyed in training flights, disassembled to study the structure, or simply scrapped.
On July 26th 1950, the Beijing defense squadron was renamed the “Air Force 1st Independent Fighter Brigade” (空军独立第一歼击机大队). By then, the Soviet Union was supplying the Chinese with more modern equipment and by mid-August, the brigade’s Mustangs were replaced by Soviet Lavochkin La-9 fighters. Once replaced, all Mustangs scattered across the country were collected and given to Aviation School No.7 to train new pilots. With this, Aviation School No.7 modified thirteen Mustangs to be two-seat trainers. This was done perhaps to speed up the training process, and to prevent accidents by rookie pilots without guidance. There is currently one known photo of the two seat trainer.
By September 1953, most Mustangs were retired from training service due to cracks in the landing gear. However, eight of them remained in service with Aviation School No.7 to train Ilyushin IL-10 pilots how to taxi their planes. A few more examples were used as teaching tools to train pilots on identifying plane parts. It is unknown when precisely the Mustang was retired once and for all.
Surviving PLAAF Mustangs
To this day, only two Mustangs formerly in PLAAF service survive in museums. The first one is a P-51K-10-NT “Red 3032” with the serial number 44-12458. This P-51K is on public display at the Chinese Aviation Museum (中国航空博物馆), sometimes also known as the Datangshan Aviation Museum located in Datangshan, Beijing. It remains in relatively pristine condition as it was in an indoors display and sheltered from the elements. Bomb hardpoints are visible under each of the wings which signifies that this Mustang perhaps once served as a fighter/bomber for the ROCAF.
The other surviving PLAAF Mustang is a P-51D-25-NA “Red 3” with the serial number 44-73920. This Mustang can be seen at the China People’s Revolution Military Museum (中国人民革命军事博物馆) in the Haidian District of Beijing. What is notable about this specific plane is that it was one of the nine Mustangs that flew over Beijing on October 1st of 1949 for the Founding of the People’s Republic of China parade. This Mustang was displayed outdoors exposed to nature for the majority of its life until the museum went under renovation when it was finally moved indoors. The Mustang has gone through minimal restoration, as it looks considerably cleaner than when it was displayed outdoors. This Mustang also had bomb hardpoints under its wings.
A total of 39 North American P-51D Mustangs were operated by the Communist Chinese forces, and later the People’s Republic of China. Within these Mustangs, an unknown amount were P-51D and P-51K models.
P-51D – An unspecified amount of P-51D Mustangs of various block numbers were operated by the People’s Republic of China. A P-51D-25-NA is confirmed to have been in service as it flew over Beijing as part of the establishment of the People’s Republic of China parade and is now in the China People’s Revolution Military Museum (中国人民革命军事博物馆) in the Beijing.
P-51K – An unspecified amount of P-51K Mustangs of various block numbers were operated by the People’s Republic of China. A P-51K-10-NT is confirmed to have been in service as it is in the Chinese Aviation Museum (中国航空博物馆) in Beijing.
P-51 Trainer – A total of thirteen Mustangs were modified by Aviation School No.7 in 1951 to be two-seat trainers. The instructor sat in the rear while the student pilot was at the front. No surviving examples are preserved to this day.
The author would like to extend his thanks to Mr. Hemmatyar for restoring some of the photos used in this article.
United States of America (1944)
Prototype Escort Fighter – 2 Built
The Consolidated Vultee XP-81 was a prototype mixed power fighter developed in late 1943 by the Consolidated Vultee Aircraft Corporation in order to meet an Army Air Force requirement calling for a high altitude escort fighter. Plagued by slow development and engine problems, the XP-81 would never see active service and development would be terminated in 1947. Despite this, the XP-81 still holds a distinct place in history as America’s first turboprop engine plane to fly and the world’s first plane to fly with a turboprop engine and a jet engine together.
With the formal introduction of the Boeing B-29 Superfortress on May 8th of 1943, it would be clear that a high altitude escort fighter would soon be needed to accompany the Superfortress on its bombing missions over the Pacific. In the summer of 1943, this need was realized and the United States Army Air Force (USAAF) issued a list of design requirements that consists of the following:
1,250 mile (2,012 km) operating radius
Fuel for 20 minutes of combat plus reserve fuel supply for landing
Cruising speed of 250 mph (402 km/h) at 25,000 ft (7,620 m)
Maximum speed over 500 mph (804 km/h)
Combat ceiling of 37,500 ft (11,430 m)
Climb rate of 2500 fpm (feet per minute) / 762 mpm (meters per minute) while at 27000 ft (8230 m)
12 ° angle of vision over the nose
* – The USAAF recommended that the designers use a two engine setup consisting of a propeller engine for long range flights while complemented by a jet engine for high speed combat situations.
Interested in this proposal, the Consolidated Vultee Aircraft Corporation, later known as Convair, began work on an aircraft which would meet the specifications, appointing Charles R. Irving, who was a chief engineer of the Vultee Field Division and Frank W. Davis, the assistant engineer, who was also the chief test pilot, as the leaders of the design team. The project was known as the “Model 102” within Consolidated Vultee. In the early stages of development, the designers faced a dilemma of engine selection. The Pratt & Whitney R-2800 Double Wasp radial engine was considered, as was the General Electric TG-100 turboprop engine. After some evaluating and testing however, the TG-100 was selected as it was deemed to have superior performance for combat and cruising situations. As for the jet engine in the rear, a relatively straightforward choice to mount a General Electric J33-GE-5 (also known as I-40) jet engine was made. After a couple of months of development, Consolidated Vultee submitted a preliminary design proposal to the United States Army Air Force in September of 1943. Relatively interested in this design, the plane was given the greenlight for further development and received the designation “XP-81” by the Air Material Command.
Detailed work on the XP-81 began in January 5th of 1944 and on January 18th, Consolidated Vultee was given the contract (no. W33-038-ac-1887) by the USAAF worth about $4.6 million to construct two flying XP-81 prototypes and one airframe for ground testing under the USAAF project name “MX-480”. Another contract followed on June 20th of 1944 worth $3,744,000 for the two flying examples, the airframe and the testing data. The contract was later modified to include 13 YP-81 under the project name “MX-796”. The construction of the first XP-81 prototype would begin on January 20th at the formerly independent Vultee aircraft factory in Downey, California but problems soon surfaced. Some time in April, the Air Material Command was notified that there would be a delay in the delivery of the TG-100 due to a couple of technical difficulties. As such, construction of the first prototype was delayed as the designers sought out an alternative engine to replace the TG-100 in June.
The Packard V-1650-3 (some sources state V-1650-7), which was the American copy of the British Rolls-Royce Merlin engine, was selected to fill in the gap and the USAAF promptly provided Consolidated Vultee with such an engine taken from a North American P-51D Mustang. Within a week of receiving the engine, Consolidated Vultee engineers were able to install it after making considerable structural modifications to the first prototype’s airframe. A radiator similar to that of the Lockheed P-38J’s “beard” radiator would also be mounted on the XP-81, under the propeller spinner. Unfortunately for the designers however, the change of powerplant would add 950 lb (431 kg) to the plane while taking away 960 hp at takeoff and 1720 hp at top speed. With the relatively slow development, the first XP-81 prototype would finally be completed in January of 1945 bearing the serial number of “44-91000”.
Although the aforementioned issues with weight gain and horsepower loss were present, the Packard engine powered XP-81 was still deemed safe for flight tests, and as such, the first XP-81 prototype was prepared for test flights at Muroc Dry Lake in California and finally took to the skies on February 7th of 1945 with Frank W. Davis in the cockpit. Amazingly enough, 46 test flights were made with the Packard engine and it accumulated a total of 47.75 flight hours. In the testing phase it was noted that with the Packard engine installed, the XP-81 had poor directional stability at low speeds and the occasional splatter of oil on the windscreen by the propellers. Plans to replace the Packard engine were brought up on May 18th of 1945 when the TG-100 turboprop was finally available. The conversion was completed and the first prototype was returned back to Muroc for more tests on June 11th. Due to the new engine installation, extensive ground work had to be accomplished before flight tests were to continue. Throughout June 23rd to December 20th of 1945, numerous ground tests were conducted and a few problems surfaced. For one, the TG-100 was difficult to start and once it did, the pilot would have difficulty controlling the propeller. As this was an early turboprop engine,
reliability was low and the turbine wheels had to be replaced constantly, sometimes only after half an hour of use. The 10 inch (25 cm) oil cooler for the TG-100 was also deemed a problem, and it was thus increased to a 12 inch (30 cm) system instead. Perhaps the biggest problem however, was the throttle lag the XP-81 suffered. Frank W. Davis describes the problem by stating “The pilot had about a 10 second lag when he wanted to go and about 2 seconds lag when he wanted to stop, with both thrust and drag being powerful and non-adjustable when they did occur.” (Consolidated Vultee XP-81, by Steve Ginter). The ground personnel concluded in these ground tests that the current Aeroproduct A542 propeller and drive shafts were incompatible with the TG-100, and that new propellers should be developed. An emergency engine feathering system was also recommended.
The first flight of the XP-81 with the TG-100 engine occured on December 21st of 1945. This was the 47th test flight the first XP-81 underwent. Performance was rather satisfactory, and the flight concluded after a mere 5 minutes. Excessive oil consumption was noted however. Test flights with the TG-100 proved disappointing as the turboprop did not perform as it was advertised, delivering less horsepower than was expected. Out of the estimated 2,300 hp the TG-100 was suppose to achieve, only 1,400 hp was achieved. The I-40 engine was no help either, as it developed nearly 250 lb (113 kg) less thrust than advertised as well. The estimated performance of 478 mph (769 kmh) at sea level was not achieved with only a mere 400 mph (643 kmh) achieved. Due to these factors, the performance achieved was similar to that of the Packard engine installation. Despite these problems, the XP-81 still did well in some aspects. The relatively decent handling and decent climb rate was complemented, as was the light controls. The second prototype (serial no. 44-91001) was produced some time before November of 1946, and was ready for flights by February of 1947. It featured a longer ventral fin than that of the XP-81 and had a four blade Hamilton Hydromatic propeller replacing the Aeroproducts propeller used on the first prototype. Unfortunately, it is unknown what date the second prototype made its maiden flight, but it is speculated that it first flew some time in February of 1947.
In total, 116 flights were made by both of the XP-81 prototypes, 22 of which were done by the second XP-81 prototype. More tests were planned, as on January 14th of 1947, Consolidated Vultee called for the following areas to be studied and tested:
Firearms testing of the Browning AN/M2 and the Hispano T31. Bombs and rockets tests will also be included.
Anti-icing equipment efficiency.
Control characteristics and lateral stability.
Cabin pressurization experiments.
Power plant operations.
However due to the previously mentioned issues of the XP-81 underperforming, the USAAF gradually lost interest in the XP-81 program. Consolidated Vultee was well aware of this, and they had been trying since December of 1946 to improve their design. A proposal was made in December 31st to the Air Material Command to fix the underperforming prototypes. This proposal suggested that an improved TG-110 (the ones that would have been used on the YP-81) should replace the TG-100 and a J33-19 jet engine should replace the J33-GE-5. The Air Material Command however was not impressed by the proposal due to the amount of redesigning and time needed and in early 1947, their engineering department ceased work on the TG-100 turboprop engine. Things would look even more grim for the XP-81 when on January 27th of 1947, the contract for the 13 YP-81 pre-
production fighters were cancelled. Finally on May 9th, the XP-81 program reached its end when the government decided to cancel the contract on its development. The two prototypes were then taken in by the USAAF on June 24th and 25th. Finalization of the cancellation was conducted on June 23rd of 1948 after the USAAF was reorganized into the United States Air Force (USAF) when Consolidated Vultee was reimbursed with $4,578,231 for their work on the program.
Though development stopped for the XP-81 program, the two prototype’s story did not end there. At the time when the USAAF took in the prototypes, the engine and propeller development branches of the Air Material Command was in the middle of developing more advanced propeller control techniques and a suitable machine was needed to perform tests on as wind tunnels and models were not available. The USAAF promptly provided the two XP-81s which were redesignated as “ZXF-81” for this new role. The two planes were then stored in Edwards AFB (previously known as Muroc AAF) for future use. Unfortunately, they were never used and on April 29th of 1949, all useful parts and gadgets were stripped from the two planes by order of the USAF. The two empty airframes were then dragged onto the photography & bombing range of the Edwards AFB.
Despite the XP-81s now sitting in the desert, Consolidated Vultee was still not willing to yield completely. The company tried proposing reviving the XP-81 program using different power plants and repurposing the role. The proposal called for the use of the British Armstrong-Siddeley Double Mamba turboprop producing 4,000 hp and a Rolls-Royce R.B 41 jet engine producing 6,250 lbf (2,835 kgf) of thrust replacing the original engines. The idea behind this was to create a ground attack aircraft which could be exported to other countries. However, this idea was understandably met with skepticism by the Air Force, but an investigation to see the feasibility of this proposal was made. On September 14th of 1950, a report was finalized stating that at least ⅔ of the airframe would need to be modified in order to mount the new engines. New drop tanks, rocket rails, hardpoints and various other parts would also need to be redesigned. Another investigation was done on this proposal by comparing the hypothetical performance to the all-turboprop Douglas A2D Skyshark, a ground attacker aircraft in service with the USAF. It was determined that the Skyshark would outperform the XP-81 with British engines in all aspects, so there was no point in developing an inferior aircraft. Another factor that was noted was the excessive amount of maintenance, training and logistics needed to service the ground attacker. With all these factors in mind, the proposal was discarded by the USAF and Consolidated Vultee finally gave up on the XP-81.
The two XP-81 airframes would remain in the desert exposed to the elements for decades until August of 1994 when Air Force Flight Test Center Museum curator Doug Nelson retrieved them. They were in derelict condition, with the second XP-81 prototype being more damaged than the first. As of 2018, the two airframes remain in the National Museum of the United States Air Force in Dayton, Ohio awaiting future restoration. Although never seeing service, the XP-81 still holds a distinct spot in history as America’s first turboprop engine powered plane to fly and the world’s first plane to fly with a turboprop engine and a jet engine together.
Airframe: The XP-81’s semi-monocoque fuselage was constructed using age hardened 24-SRT aluminum alloy, followed by the exterior surfaces being flush riveted. The entire fuselage is made from metal. The wing design was a NACA laminar flow type, made from aluminum-alloy. The design allowed for a stressed-skin wing which was flush riveted as well, with the rivet heads being milled. Due to the relatively heavy materials used in the wings, the surface was relatively smooth thus allowing for good aerodynamics. The majority of the heavy plating was mounted in the frontal 34.5% of the wings, and thus allowed a decent mount for aerial weapons and permitted ordinance to be mounted. There were spoilers present on each wing which automatically operated in accordance to the ailerons. Another interesting feature was a thermal anti-ice system derived from the hot hair emitted from the TG-100 turboprop and the exhaust. Within the fuselage two fuel tanks were installed directly behind the cockpit, making for a total 811 gallons (3670 L) of fuel. The fuselage also housed the XP-81’s tricycle landing gear which was electrically operated. The main gear was fitted with disc brakes, also doubling as a parking brake.
The canopy on the cockpit was based off of the British bubble design, which allowed for a relatively clean 360° view. This type of canopy was used on many planes in service with the United States and Britain. The canopy would be controlled by the pilot via a hand crank on the left hand side of the cockpit. For fatal combat situations, an emergency canopy jettison system was provided allowing for the pilot to bail out quickly. The pilot’s seat was an ordinary World War II styled seat, but this was eventually replaced with an ejection seat modelled after the one used on the Convair XP-54. As the XP-81 was a long range fighter, an automatic piloting system was also installed. The cockpit would also be pressurized using the air from the TG-100 engine. For pilot comfort, a temperature system was installed allowing for optimal temperatures in all climate and altitudes.
For communication, the XP-81 was fitted with a VHF (Very High Frequency) SCR 522-A radio set. The cockpit also had room for a BC-1206 beacon receiver and an SCR 695 identification friendly-or-foe system, but these were never installed. The pilot would operate the SCR 522-A radio from the right side of the cockpit, where the radio controls were based.
It is also interesting to note that the second YP-81 prototype had a longer ventral fin than the first prototype.
The XP-81’s design called for a General Electric TG-100 (also known as XTG-31-GE-1) turboprop and General Electric/Allison J33-GE-5 (I-40) jet engine as its power plants. The first prototype had a four blade Aeroproducts A542 brand propeller driving the TG-100 while the second prototype had a Hamilton Standard Hydromatic 4260 propeller instead. The TG-100 had a capacity for 8 gallons (30 L) of oil while the I-40 had 3.5 gallons (13 L). In terms of fuel, 811 gallons (3,670 L) was available in the XP-81’s two standard fuel tanks in the fuselage, but could go up to 1,511 gallons (5,720 L) with the installation of drop tanks.
Armament: The standard armament envisioned for the production P-81 would consist of either six 12.7x99mm Browning AN/M2 machine guns with 400 rounds each or six 20x110mm Hispano T31 cannons with 200 rounds each. The loadout of these guns would be in groups of three in each wing. For ordinance, a single hard point was mounted under each wing, allowing the plane to carry two bombs size ranging from 100 lb (45 kg) to 1,600 lb (725 kg), allowing for a maximum of 3,200 lb (1,451 kg). Chemical tanks, drop tanks, depth charges could also be equipped. Alternatively, 14 High velocity Aircraft Rockets (HVAR) could be carried.
XP-81 – Prototype fighter variant powered by a TG-100 turboprop and I-40 jet engine. Two examples were produced and extensively tested up until the cancellation of the project. Both prototypes were redesignated as “ZXF-81” in 1948 and stored in Edwards AFB. They would be stripped of useful parts and towed to the photography/bombing range near Edwards AFB and left there in derelict condition until August of 1994 when they were retrieved by Doug Nelson. The two airframes still survive to this day and are currently awaiting restoration at the National Museum of the United States Air Force in Dayton, Ohio.
YP-81 – Planned batch of 13 pre-production fighter variant powered by a lighter but more powerful TG-110 turboprop engine and an uprated General Electric J33-GE-5 turbojet engine. These planes would have been armed with either the Browning AN/M2 machine guns or the Hispano T-31 cannons. It would have differed from the XP-81 by having the wings moved back 10 inches (2.54 cm). No YP-81s were produced.
ZXF-81 – Post development termination designation for the two XP-81 prototypes. This designation signified that the prototypes were now flying test beds. However, no use of the prototypes after its termination was noted.
XP-81 (British Engines) – Unofficial variant proposed by Consolidated Vultee some time in 1949/1950 calling for the revival of the XP-81 project using British Armstrong-Siddeley Double Mamba turboprop producing 4,000 hp and a Rolls-Royce R.B 41 jet engine producing 6,250 lb (2,835 kg) of thrust replacing original engines. This new variant would be used as a ground attacker that would be solely used for export. This proposal never saw any development and was thus discarded.
United States of America – The XP-81 was intended to be used by the USAAF, but development carried over to the USAF. The project was eventually cancelled.
Consolidated Vultee Aircraft Corporation XP-81 (Taken from “Consolidated Vultee XP-81 by Steve Ginter”)
50 ft 6 in / 15.39 m
44 ft 8 in / 13.61 m
13 ft 10 in / 4.21 m
425 ft² / 39.48 m²
45.9 ft² / 4.26 m²
80 in² / 516.12 cm²
Wings Sweep Back
1x General Electric XTG-31-GE-1 (TG-100) turboprop 1x General Electric / Allison J33-GE-5 (I-40) jet
TG-100: 8 gallons / 30 L I-40: 3.5 gallons / 13 L
12,755 lb / 3,887 kg
19,500 lb / 8,845 kg (Maximum internal fuel with reduced armaments)
Maximum Combat Weight
24,650 lb / 11,181 kg
811 gallons / 3,070 L – Internal Fuel Tanks 1511 gallons / 5,720 L – Internal Fuel Tanks + Drop Tanks 350 gallons / 1,325 L – Individual Drop Tank
Center of Gravity
Max Forward – 17% Max Aft – 27%
Rate of Climb
0 to 5,000 ft / 0 to 1,524 m – 5,200 fpm / 39.31 mps
Time of Climb
30,000 ft / 9,144 m in 9.6 minutes
299 mph / 481 kmh at Sea Level 253 mph / 407 kmh at 15,000 ft / 4,572 m 224 mph / 360 kmh at 30,000 ft / 9,144 m
546 mph / 877 kmh Diving tests were never finalized due to propeller and engine problems. Flight #90 on September 4th of 1946 achieved the highest speed as mentioned above.
Conditions under maximum combat weight
Ferry Range – 2,393 mi / 3,851 km Speed at 247 mph / 397 kmh – 2,002 mi / 3,222 km Speed at 274 mph / 441 kmh – 1,622 mi / 2,610 km
47,000 ft / 14,000 m
SCR 522-A VHF Radio
6x 12.7x99mm Browning AN/M2 (400 rpg, 2,400 total) or 6x 20x119mm Hispano T31 (200 rpg, 1,200 total) Never Fitted on Prototypes, Intended Armament
1x K-14 Gyro Gunsight
2x hardpoints capable of carrying 3,200 lb / 1,452 kg of either bombs, depth charges, chemical tanks or drop tanks or 14x 5 inch / 12.7 cm High Velocity Aircraft Rockets (HVAR)