Aircraft, awful and awesome:
P.B.31E ‘Night Hawk’

Dr. Marshall Michel
86th Airlift Wing historian

***image1***While World War I produced a huge variety of unsightly aircraft, certainly one of the most unattractive was the British Pemberton-Billing P.B. 31E “Night Hawk,” a huge “fighter” that was intended to shoot down German Zeppelins over England.

The twin engine “Night Hawk” had swept quadruplane wings and a biplane tailplane with twin fins and rudders, a crew of five and carried 2,000 pounds of fuel in armored fuel tanks so it could orbit all night – up to 18 hours – at slow speed waiting for a Zeppelin to appear.

To destroy the Zeppelin, a veritable gun emplacement that carried a two-pounder (about 37mm) “Davis Gun” was perched on top of the Night Hawk’s fuselage with a 360-degree arc of fire and 20 shells for the gun.

The Davis Gun was a recoilless rifle that fired unique rounds that were a combination of a two-pound high-explosive shell at one end, a propellant charge, and two pounds of lead bird shot in the other end. When the gun fired, it expelled the two pounds of lead shot out of the back to balance the recoil of the two pound shell.

The Night Hawk had other advanced features for its intended role. To locate the Zeppelin, the aircraft had a trainable searchlight in the nose, powered by aviation’s first auxiliary power unit, a two-cylinder engine mounted behind one of the main engines. The cockpit was enclosed and heated, and even carried a bunk for one of the crewmembers to rest during the long missions.
The Night Hawk actually began test flights in February 1917, but seemed to be woefully underpowered by its two 100 horsepower engines. It was hoped to reach speeds of 75 mph, but there is some question about whether it could reach that speed, and whether it could climb high enough to attack a Zeppelin. 

In any event, the Zeppelins proved vulnerable to smaller, faster-climbing fighters carrying normal machine guns with incendiary shells, and the Night Hawk program was dropped.

Ironically, the almost repulsive Night Hawk was the first aircraft built by the Supermarine Aviation Works, which later produced what is generally considered one of the most beautiful aircraft ever built – the Supermarine Spitfire of World War II.