Tag Archives: Attacker

Hütter Hü 136 Stubo

Nazi flag Nazi Germany (1938)
Armored Ground Attack Aircraft – 1 Replica Built

Stubo I Replica [aviationmuseum.eu]
The Hütter 136 was an interesting concept for a ground attack aircraft that employed numerous experimentations in its design. The cockpit was fully armored, the landing gear was replaced by a skid, and the entire propeller would be jettisoned off during landings. The aircraft came in two forms: the Stubo I, a short design with the ability to carry an external 500 kg bomb, and the Stubo II, a lengthened version that could carry two internal 500 kg bombs. The program never progressed as far as production and work stopped on the project shortly after the Henschel Hs 129 was ordered for production.


Artist’s Impression of the Stubo I [Heinz Rodes]
During the years leading up to the Second World War, Nazi Germany found itself needing a competent air force to rival those it would soon face. Restrictions set by the Treaty of Versailles severely hindered the German military both in size and equipment in order to ensure that German power would not threaten the continent again, as it did during the First World War. History notes that the Germans broke this treaty, at first covertly and then overtly, with the Allies showing no response or protestation to the blatant violations. Germany began amassing a massive military force in preparation for war. New programs and requirements were laid down in preparation for the inevitable war. These projects included many newly tested concepts, such as dive-bombing. The Junkers Ju-87 Stuka proved the effectiveness of dive bombing in the Spanish-Civil War, with a famous example being the Bombing of Guernica, but a newer attacker was eventually needed to complement it. An order in 1938 was put out by the Reichsluftfahrtministerium (Aviation Ministry, “RLM”) to develop a new armored ground-attacker. One of the companies that would participate in this requirement would be Hütter.

2-way and cutaway of the Stubo II

The designs of Ulrich and Wolfgang Hütter are relatively unheard of when it comes to aircraft. They began their aviation career designing glider aircraft in the 1930s, such as the popular Hü 17, some of which were used post-war. The Hütter brothers built a career in designing aircraft for the Luftwaffe (German Air Force) between 1938 and 1944 under the codename of Ostmark. The two began working on the project mentioned before for an RLM request for a new ground-attacker in 1938. The requirement laid down very specific guidelines to be followed. The new aircraft needed to have good flight performance and an armored airframe for extra protection, as well as enough speed to evade fighters. In preparation for the new designs, the RLM notified designated factories that would begin to produce these airframes upon adoption into service. The Hütter brother’s response would be the Hü 136. Other competitors included the Henschel Hs 129 and the Focke-Wulf Fw 189V-1b, an armored ground attack version of their reconnaissance plane. Not all projects for a new attacker were armored at this time. Other new designs included the Junkers Ju 187 and Henschel Hs P 87.

The Hütter Hü 136 was nicknamed the Stubo, a shortened version of the name Sturzbomber (Dive Bomber). The aircraft itself would be a single-engine design. Two versions of this aircraft existed. The first, Stubo I, was meant to fill the need for a heavily armored attacker and would be used in ground-attack and dive-bombing tactics. The second was the Stubo II, a two-seater which was essentially a longer version of the Stubo I and carried twice the bomb load internally. The flight performance of the Stubo II was estimated to be the same as that of the Stubo I although, given the design characteristics, that estimation is highly doubtful. The two designs did not meet the requirements for bomb load and range. To make the aircraft more efficient, the brothers took an interesting design change. Taking a note from their glider designs, they removed the conventional landing gear and replaced it with an extendable landing skid, which made the aircraft lighter and freed more space for fuel. This, however, posed serious designs problems. The Hü 136 now had to take off using a detachable landing gear dolly, similar to how the Messerschmitt Me 163B rocket plane would take off a couple years later. Due to this, the propeller would not have enough clearing and would hit the ground during landings. To fix this, the two brothers made the propeller detachable. During landings, the aircraft would eject the propeller, which would gently parachute to the ground above an airfield for recovery and reuse. To assist in landings, a new surface brake was also added to the aircraft.

2-way and cutaway of the Stubo I

The far more conventional Henschel Hs 129 would be designated the winner of the competition. Subsequently, no construction was ever started on either the Stubo I or II. The Stubo proved to be an interesting but flawed concept. The limited visibility from the armored cockpit would negatively affect the aircraft in all operations. Dogfighting, bombing and even flying in general would be affected by the cockpit’s design. The change in landing gear design may have extended the range and lowered weight, but pilots now had to learn how to land using a skid. The fact the entire propellor evacuated the aircraft was a huge issue in itself. Once ejected, the landing could not be aborted, and if the landing attempt failed, there was no chance to loop around and try again.

This, however, would not be the last project designed by the Hütter brothers for the Luftwaffe. Wolfgang would begin working on a long-range reconnaissance version of the Heinkel He 219 called the Hütter Hü 211. Another project is the rather unknown Hütter Fernzerstörer (Far Destroyer), a long-range turboprop attacker meant to be used on the Eastern Front. With the war ending, no further Hütter aircraft were designed. One would think the story of the Stubo ends with its cancellation, but the story continued rather surprisingly recently. The Military Aviation Museum in Virginia Beach, VA, acquired a full-scale replica of the Stubo I in 2017 and it is currently on display in their German Experimentals section, along with full-scale replicas of other “Luft 46” designs.


The Stubo I was a single-engine armored ground attacker. In the front, it mounted a detachable propeller and a Daimler-Benz DB 601 inline engine. In the fuselage, a large gap was present between the engine and cockpit. This was most likely the fuel tank where the fuel tank was placed. Beneath the aircraft, a single 1010 Ibs bomb (500 kg) was mounted on an external hardpoint. This hardpoint most likely would be in the way of the landing skid, implying the payload had to be dropped before making an attempt at landing. For takeoff, a dolly would have to be mounted beneath the aircraft. This would be jettisoned shortly after the Stubo would be airborne. For landing, the aircraft would use an extendable skid. The wings of the aircraft had slight dihedral, which meant the wings were angled upward from the body. The Stubo I had an armored steel cockpit that was completely enclosed. For visibility, a small sight in the front and two side portholes were given. Had the aircraft been produced, peripheral vision would have been nonexistent and dogfighting would have been near impossible if it needed to defend itself. Normal operations, such as navigation and landing would have also been hindered, while combat operations such as target acquisition and attack run planning would have been exceedingly difficult. A tailfin was mounted directly behind the cockpit and not in a conventional tail design. Sources also mention the Stubo I would have mounted machine-guns, but the plans do not show exactly where or of what type these would have been.

Artist’s Impression of the Stubo II [Heinz Rodes]
The Stubo II was virtually identical to the Stubo I, aside from its extended fuselage. This lengthened design would allow the Stubo II to carry two 1010 Ibs (500 kg) bombs in a bomb bay, compared to the single bomb carried on a hardpoint by the Stubo I. Among smaller differences, the Stubo II’s wings had no dihedral compared to the angled dihedral of the Stubo I. With the lengthened fuselage, the landing skid was also extended to accommodate the longer airframe. It most likely also carried over the machine guns used on the Stubo I. The Stubo II uses nearly identical sized wings to the Stubo I, which gives the Stubo II a rather odd design, having the body lengthened but the wing size remaining the same. This would have definitely affected performance and possibly would have made the aircraft more unstable in maneuvering with the extra weight.



  • Stubo I – Armored ground-attacker that would carry a single external 500 kg bomb. Sources also mention machine guns, but documents don’t show where exactly they would have been located.
  • Stubo II – A lengthened version of the Stubo I, the Stubo II had an internal bomb load of two 500 kg bombs.




  • Nazi Germany – If the Hütter 136 would have entered production, Nazi Germany would have been the main operator of the craft.

Hütter 136 “Stubo I” Specifications

Wingspan 21 ft 4 in / 6.5 m
Length 23 ft 7 in / 7.2 m
Height (estimate) 5 ft 3 in / 1.6 m
Engine 1x 1,200 hp (894 kW) DB 601 Inline Engine
Loaded Weight 8,160 lbs / 3,700 kg
Maximum Speed 348 mph / 560 km/h
Range 1,240 mi / 2,000 km
Maximum Service Ceiling 31,170 ft / 9,500 m
Crew 1 pilot
  • 1x 1010 lbs (500 kg) bomb
  • At least 2 machine guns of unknown type (Most likely MG 15 or MG 17)


Illustrations by Haryo Panji https://www.deviantart.com/haryopanji

Stubo I Side View [Haryo Panji]
Stubo II Side View [Haryo Panji]


Ba.88 Lince 100-4

Breda Ba.88 Lince

italian flag Italy (1939)
Fighter Bomber and Reconnaissance – 155 Built

The Breda Ba.88 Lince, Italian for Lynx, saw service with the Reggia Aeronautica during the early days of WWII. The Lince prototype was initially touted as a propaganda tool for fascist Italy with its bona fide world records for airspeed. However it’s eventual service life was cut short by drastic performance problems by the time the weight of military armaments, eventually earning it a popular reputation as one of the worst aircraft failures of all time.


On January 20th of 1936, the Italian Air Force (Reggia Aeronautica) put in a request to all Italian aviation companies for a new multi-purpose twin-engine aircraft. The new aircraft’s specification is that it should be capable of achieving a top speed of least 300 mph (470 km/h), have a service ceiling of 20,000 ft (6000 m), a flight range of 1,250 mi (2000 km), and good takeoff and landing characteristics. The armament was to consist of several 12.7 mm machine guns or a few 20mm cannons. Several companies responded to this request, with their suggestions. In the end the Breda Ba.88 aircraft was chosen.

Italian designers Antonio Parano and Giuseppe Panzeri had plans to make the Ba.88 a multi-purpose two-seat aircraft, which in essence meant that it would be suitable for long-range reconnaissance, bombing operations, and to serve as a heavy fighter aircraft similar to the German Messerschmitt Bf 110.


The Ba.88 was a twin engine all-metal high-wing monoplane. The engines on the prototype were two 900 hp (671 kW) Gnome-Rhone K-14 radials. It had a retractable tailwheel landing gear. The prototype at first had a single vertical tail assembly but it was later changed to a new modified tail unit with twin fins and rudders.

The Lince Prototype

The Ba.88 prototype, designated MM 302, had its first test flight in October 1936. The first test pilot was Furio Niclot Doglio, Breda’s main test pilot. In February 1937 the Ba.88 prototype was sent to the Guidonia for more army flight tests. In April 1937 two new speed over distance world records were achieved, with average speed of 321 mph (517km/h) over 62 miles (100km) and the second of 295 mph (475km/h) over a distance of 621 mi (1000km). These records were set by Furio Niclot Doglio. Later that year he reached a top speed of 325.6 mph (524 km/h) and 344.2 mph (554km/h). The results of these test flights were more than satisfactory, and often used by the Italian fascist regime for propaganda purposes. But this string of successes did not last for long.

With the installation of military equipment and weapon armament the performance and flight characteristics fell off dramatically, which affected the operational efficiency and history of this Lince. Top speed achieved with the full military equipment and armament was much lower than that on the test flights. This gave rise to a question of its use in the role of a fighter aircraft. Italian army test pilots expressed concern over its flight characteristics, since even the simple maneuvers were hard to achieve. In order to try to fix some of these issues, a number of weight saving modification were done, such as reducing the main armament and installing two new 1000 hp Piaggio engines. Later during the war, even the rear gun position was removed in order to save weight. But these problems would be never solved completely. Despite this an order was placed for 88 new Ba.88 aircraft.

The Ba.88 production model was powered by two 1000hp (746 kW) Piaggio P.XI RC.40 14-cylinder radial piston engines. Maximum top speed with the new engines was 304 mph (490 km/h), effective range was 1000 mi (1640 km) and the service ceiling was up to 26,000 ft (8000m).

The main armament consisted of three 12.7mm Breda-SAFAT heavy machine guns plus one 7.7mm machine gun also Breda-SAFAT type, used by the rear gunner. Total bomb load was around 2,200 lbs (1000kg), in the fuselage bomb-bay or three 200kg bombs carried semi-exposed in individual recesses in the lower fuselage.

In combat

After the German attack on the Allies in France in May 1940, Italy also declared war on the Allies on 16 June 1940 and started to attack the French positions to the south. The Lince saw its first combat actions during those operations. Some 12 planes from the Regia Aeronautica 19° Gruppo Autonomo (independent group) made several bombing attacks raids on airfields in Corsica. A few days later a group of nine Ba.88 planes made a new bombing raid. But after the end of the Battle of France, Italian combat analysis of this air attacks had led to the conclusion that the Ba.88 aircraft had only limited value as a effective operational aircraft.

The next combat use of the Ba.88 was in North Africa. The Linces of the 7° Gruppo Autonomo were used in Libya against the British forces. Although they were equipped with special sand filters, the engines overheated and failed to deliver their designed power. Many planned attacks, such as the one on targets at Sidi Barrani in September 1940, had to be aborted. The Ba.88 aircraft had failed to gain sufficient altitude or even maintain formation, but the biggest problem was  the inability to reach the speed that the manufacturers claimed it had.

Because of these problems, most if not all surviving Linces were been stripped of all useful equipment and armament and were scattered around major airfields mostly to act as decoys for British attacks. Ironically at that time, a further two batches of new Ba.88s were being delivered. Some 19 from Breda and 48 examples from IMAM were mostly sent straight to the scrapyard.

But the story of the Ba.88 does not end there. Three or more Ba.88 examples were modified by the Agusta aircraft plant in 1942 to be used as a improved ground-attack aircraft. Sources are not precise of how many were modified, the number of modified aircraft ranges from 3 to 14. The modification included increasing the wingspan by 6.5 feet (2m) in the hopes of alleviating wing loading problems. Two new Fiat A.74s engines were installed and the armament was increased up to four 12.7mm machine guns and dive brakes were installed. This modified Ba.88, now called the Ba.88M, were delivered and used by the 103° Gruppo Autonomo Tuffatori (independent dive-bombing  group) stationed at Lonate Pozzolo on 7 September 1943. They were also used and tested by Luftwaffe pilots. Their fate is not known.


The Breda Ba.88 has a popular reputation as the “worst operational aircraft.” This is in part due to the vast difference in performance from the sleek and advanced-for-the-time prototype that was able to set world speed records, until production aircraft fitted with the weight of wartime armament drastically hampering the plane’s flight characteristics as previously mentioned. However it should be noted that by most accounts there are no prominent records of catastrophic structural failure, crashes, accidents, or combat losses. Perhaps the primary reason for this reputation is how quickly the aircraft’s operational service life was dispensed with, the marked difference in the performance of the prototype versus the fully outfitted wartime production model, and the premature relegation to the scrapyard or the duty of airfield decoy.


Production of initial production run of the Lince started in May of 1939 and ended in October of that same year. The first batch of some 80 aircraft, plus eight dual-control trainers were built by Breda. Later, by the second half of the 1940 some 67 more examples were built in small batches, 19 by Breda and 48 by IMAM. In the end total production was 155 aircraft plus the initial prototype.


  • Ba.88 Prototype – Initial prototype, set several world speed records, 1 built
  • Ba.88 Lince – Main production model, 155 built
  • Ba.88 Trainer – Dual-control trainers, 8 built
  • Ba.88M – Three modified aircraft in order to improve flight performance

Breda Ba.88 Lince Specifications

Wingspan 51 ft 3 in / 15.6 m
Length 35 ft 4 in / 10.79 m
Height 10 ft 2 in / 3.1 m
Wing Area 358.8 ft² / 33.3 m²
Engine Two 1000 hp (746 kW) Piaggio P.XI RC.40 14-cylinder radial piston engines.
Empty Weight 10,250 lb / 4,650 kg
Maximum Takeoff Weight 14,900 lb / 6,750 kg
Fuel Capacity 419 U.S. Gal / 1,586 L
Climb Rate 9,843 ft / 3,000 m in 7 minutes & 30 seconds
Maximum Speed 304 mph / 490 km/h
Range 1,000 mi / 1,640 km
Maximum Service Ceiling 26,250 ft / 8,000 m
Crew 1 pilot & 1 rear gunner
  • Three nose mounted 12.7mm Breda-SAFAT heavy machine guns
  • One rear 7.7mm Breda-SAFAT machine gun
  • Total bomb load around 2,200 lbs / 1000kg


Ba.88 Lince 100-7
Ba.88 Lince 100-7 – circa 1940
Ba.88 Lince 100-4
Ba.88 Lince 100-4 – July 1940


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Mondey, D. (2002). The Hamlyn concise guide to Axis aircraft of World War II. Edison, N.J: Chartwell Books.
Chant, C. (2002). Aircraft of World War II : 300 of the world’s greatest aircraft. Rochester: Grange Books.
Aviastar.com. (n.d.). Breda Ba.88 Lince.
Airwar.ru. (2016). Ba.88 Lince.
Side Profile Views by Ed Jackson – Artbyedo.com