PB.29E & PB.31E Supermarine Nighthawk

UK Union Jack United Kingdom (1915 & 1917)
Anti-Airship Fighter – 1 Each Built

Supermarine PB.31E Nighthawk

In 1915, Germany began bombing Great Britain by Zeppelin. For the first time, Britain itself was under threat by enemy aircraft. Early attempts to counter the Zeppelins were ineffective. The Royal Air Corps needed an aircraft to be able to endure long, nighttime missions to chase the Zeppelins. The Pemberton-Billing aircraft company designed the PB.29E quadruplane for this task. The aircraft didn’t perform as hoped, but before a final conclusion could be made it was lost in a crash. Years later in 1917, with the company under new management and renamed Supermarine, the program would rise again as the PB.31E.  The PB.31E was dubbed the Nighthawk, and like its predecessor, proved to be ineffective in the role. The fighter is significant for its unusually large quadruplane layout and the first aircraft to be built by Supermarine.


The arrival of the Zeppelin in 1915 as a new type of weapon was an unwelcome one. It offered a new way of strategic bombing, as Zeppelins were faster and able to ascend higher than aircraft at the time. Zeppelins also served as a weapon of terror, as the civilians of England had never been faced with anything like it before, especially since the Zeppelins attacked mainly at night. Early attempts to counter Zeppelin raids proved ineffective, as anti-aircraft guns had a hard time spotting and aiming at the Zeppelins. Early forms of countermeasures involved aircraft dropping flares to illuminate the Zeppelins for gunners to see. None of these aircraft were used to actually intercept the airships. The Royal Air Corps needed an aircraft that would be able to reach and pursue Zeppelins on the homefront and on the battlefield. A potential solution came from a man named Noel Pemberton Billing.

Noel Pemberton Billing (1881-1948)

Noel Pemberton Billing was a man of many talents. He was an inventor, aviator, and at one point a member of Parliament. At the time, he was invested in many forms of new technology and aircraft was one of them. Having formed his own aircraft company in 1913, he built several aircraft types for the Royal Naval Air Arm (RNAA), such as the PB.25. He had taken a short break from designing planes for the RNAA and wanted to pursue aircraft to help in the war effort. The task of taking on Zeppelins got him interested in designing a plane to fill the role.

His answer was the PB.29E, a quadruplane aircraft. Information regarding the PB.29E is sparse and no specifications can be found for it. To get the aircraft to the altitudes at which Zeppelins usually lurked, Pemberton Billing applied triplane principles in making the aircraft, except taking it a step further and adding an extra wing. Having more wings, in theory, would assist with lift, a necessary factor when trying to chase the high-flying Zeppelins. Work began in late 1915, with the aircraft being finished before winter. The PB.29E was intended to fly for very long missions and needed to operate at night. To assist in spotting the behemoths, a small searchlight was to be mounted in the nose of the aircraft. The sole PB.29E crashed in early 1916. From test flights, the aircraft proved to be cumbersome and would not have been able to pursue Zeppelins. The two Austro-Daimler engines did not prove to be sufficient for the intended role, and performance suffered from it.

German Navy – R Class Zeppelin L 31

On September 20th, 1916, Noel Pemberton Billing sold his company to Hubert Scott Paine so he could become a member of Parliament. His career in Parliament was full of slander and conspiracy, and ultimately negatively affected the war effort. Soon after being acquired, Paine renamed the company as the soon to be famous Supermarine Aviation Works, in honor of the firm’s telegraph address. Work continued on a Zeppelin interceptor, which would eventually become the PB.31E. The PB.31E was technically the first aircraft built by Supermarine and it resembled a larger and more advanced version of the PB.29E. It retained many aspects from its predecessor: the quadruplane layout, the mounted searchlight, and endurance for long nighttime missions. The armament was expanded with a second Lewis gun mounted in the rear cockpit as well as a Davis gun mounted on top of the cockpit above the wings. To make the crew more comfortable, the cockpit was fully enclosed, heated, and had a bunk for crewmembers. The Austro-Daimler engines were replaced by 100hp Anzani radial engines. Expected speed was 75 mph (121 km/h) and it was to operate up to 18 hours.

The design team poses in front of the newly completed Nighthawk, fourth from the left is R.J Mitchell.

The aircraft was constructed in February of 1917, with a second in the works. On board the project was R.J Mitchell, the future designer of the Supermarine Spitfire. He began as a drafstman for the company and several designs concerning the fuselage and gun mounts of the PB.31E are labeled with his name. To the engineers, the aircraft was dubbed the Supermarine Nighthawk, however, this name was never official. Early flights were conducted at the Eastchurch airfield by test pilot Clifford B. Prodger. Tests showed that, like its predecessor, the engines weren’t capable of propelling the aircraft to its desired level of performance. To reach altitudes most Zeppelins were found at took an hour. Not to mention, newer Zeppelins could go even higher. Its expected 75 mph (121 km/h) top speed was never reached, with the aircraft only going 60 mph (96 km/h). However, it had a safe 35 mph (56 km/h) landing speed, which would have given the aircraft easy landing capability. With the performance lacking, the RAC deemed the project to be a dead end.

With the introduction of new incendiary rounds which easily ignited Zeppelins, Britain could defend itself with the improved AA guns. Along with the new rounds, the RAC started using the Royal Aircraft Factory B.E.2 to intercept Zeppelins at night. Originally intended for dogfighting, the B.E.2 proved to be ineffective and slow against fighters, but Zeppelins were easier, and much larger targets. With the Nighthawk now not needed, Supermarine ended up scrapping the first and incomplete second prototypes in 1917. Although the Nighthawk would never have been successful had it entered production, it still represents major innovations in aircraft design. It was one of the first true night-fighting aircraft to be designed, a concept later heavily utilized in the Second World War. The honor of being the first aircraft built by Supermarine under their name also goes to the Nighthawk.


Overhead and side schematic views of the PB.29E

The PB.29E was a quadruplane designed to chase and intercept Zeppelins. Its fuselage was mounted between the lower two wings, with a gunner port being mounted in the upper two wings, leaving an opening in the middle between the two. Two crewmembers occupied the central fuselage with a single gunner gunner position in a seperate section above. The cockpit was open to the elements, as well as the gunner port. For armament, a single Lewis gun was mounted for attacking Zeppelins. For engines, the PB.29E had two Austro-Daimler six-cylinder engines in a pusher configuration. The tail itself was doubled.

Schematics for the Nighthawk with R.J Mitchell’s initials.

The PB.31E was a quadruplane like the PB.29E, but it was larger utilized a different fuselage design. Instead of having the fuselage between the lower two wings, the PB.31E positioned its body between the middle two wings. The body itself was of all wooden construction. To reduce splinters if the aircraft was fired upon or in the event of a crash, the fuselage was taped and covered in heavy fabric. To make the long missions more comfortable the cockpit was heated and completely enclosed by glass. A bunk was added for one crew member to rest during the flights as well, as the expected flights could last up to 18 hours. A searchlight mounted protruding from the center of the nose for use in patrols at night. The searchlight was movable to allow pointing it at different targets. It was powered by an onboard dynamo hooked up to a 5hp A.B.C petrol engine. For fuel storage, the PB.31E had 9 individual petrol tanks located around the cockpit area. The tanks were built to be interchanged if they were damaged or empty. In the front of the aircraft were several slits behind the searchlight that would assist in cooling. The wings of the PB.31E had significant cord to them. The tailplane was doubled like on the PB.29E, and the tail itself was lower to allow the rear mounted Lewis gun more range

The newly completed PB.29E, the gunner position between the two topmost wings is easily visible

of fire. For engines, the PB.31E had two Anzani radial engines in tractor configuration. These engines gave the PB.31E its slow speed of 60 mph (96 km/h), and its hour-long ascent to 10,000 ft (3000 m). The fluid lines, controls and other parts connected to the engines were placed outside the fuselage in armored casings. For armament, the PB.31E carried a frontal Lewis gun, a top mounted Davis recoilless gun and a rear Lewis gun. The Davis gun was built on a mount that allowed an easy range of motion in most directions. Lewis gun ammo was stored in six double cartridges and 10 Davis gun rounds were stored onboard as well.  Also on board were an unknown amount of incendiary flares to be dropped should a Zeppelin be directly below the craft.


  • 29E– First aircraft built for the Anti-Zeppelin role. Armed with a single Lewis gun. Crashed during testing.
  • 31E– Second aircraft. One prototype and one unfinished plane. Resembled a larger version of the PB.29E. Carried a Davis gun and two Lewis guns. Scrapped once the design was deemed unworthy.


  • Great Britain – The two prototypes were built and tested in England.

Supermarine PB.31E Nighthawk Specifications

Wingspan 70 ft / 18.29 m
Length 36 ft 11 in / 11.24 m
Height 37 ft 9 in / 5.4 m
Wing Area 962 ft² / 89 m²
Engine 2x 100 hp ( 76kW ) Anzani Radial Engines

Empty 3677 lbs / 1667 kg
Loaded 6146 lbs / 2788 kg
Climb Rate  

Time to 10,000 ft / 3047 m 60 minutes
Maximum Speed 75 mph / 121 km/h
Cruising Speed 60 mph / 96 km/h
Landing Speed 35 mph/ 56 km/h
Flight Time Up to 18 hours of continuous flight
Crew 3-5 Crew

1 Pilot

2-4 Gunners

Armament ●      2x 7.7mm Lewis Guns

●      1x 1 ½ Pounder Davis Gun (10 rounds)

●      1x Frontally-mounted Searchlight

●      Unknown amount of incendiary flares



Side profiles by Ed Jackson – www.artbyedo.com

Pemberton-Billing PB.29E
Supermarine PB.31 Nighthawk
The PB.29E under construction in Woolston
A frontal view of the PB.29E, note the searchlight
The newly constructed Nighthawk sits in a hangar at Woolston
The Nighthawk on the runway, notice the weapons and spotlight are absent




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