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| Public domain image |
| Information | |
|---|---|
| Manufacturer: | Supermarine |
| First flight: | 1917 |
| Propulsion: | Azani radial engine (2) |
| Withdrawn: | 1917 |
| Number built: | 1 |
This was the Supermarine PB 31E, like the 29E it was a large quadruplane 11.27m long and with a wing span of 18.28m. It was made more sturdy than the 29E with a planned crew of 5 and heavily armed with a 1½-pdr recoiless gun and twin Lewis machine guns. It was intended to be able to stay aloft for up to 18 hours and carried a searchlight that was powered by a separate engine and thus was probably one of the first aircraft to carry an auxiliary power unit. Because of the long planned duration it was fitted with some basic comforts for the crew including a heated cabin. The aircraft also carried armour in some key areas and the cockpit was bound with fabric to avoid wood splinters in the event of a crash to protect the crew.
The problem with all of these innovative and advanced features was that they weighted a lot! The PB 31E weighed over 2787kg when loaded and there simply wasn't the engine technology at the time to adequately power such a plane. Two 100hp Anzani engines powered the PB 31E and were enough to get it airborne but not enough to give it sufficient performance to perform in the anti-zeppelin role. The PB 31E took an hour to climb to over 3,000 metres which meant that zeppelins could easily escape it by ditching ballast and climbing rapidly. The design speed had been 75mph (120kph) which was considered fast enough to catch zeppelins (though some zeppelins could go faster than that in favourable conditions) but it is reported the PB 31E struggled to pass 60mph (97kph).
The PB 31E first flew in February 1917 but by then it was apparent there were serious flaws in the concept, highlighted by the PB 31E's poor performance. Unable to pursue a zeppelin it's only chance of success would have been the sheer luck of being in the right place at the right time and firing on the zeppelin before it got out of range. It's main armament, a 1½ pounder Davis non-recoil gun, was also rather unwieldy.
The sole PB 31E was scrapped in the Summer of 1917, the second planned example never being built. The PB 31E, which was given the name Night Hawk, was technically innovative and it's concept could maybe have worked with more powerful engines and better performance. In the event the zeppelin was near the end of it's time as a military weapon in any case.
The problem with all of these innovative and advanced features was that they weighted a lot! The PB 31E weighed over 2787kg when loaded and there simply wasn't the engine technology at the time to adequately power such a plane. Two 100hp Anzani engines powered the PB 31E and were enough to get it airborne but not enough to give it sufficient performance to perform in the anti-zeppelin role. The PB 31E took an hour to climb to over 3,000 metres which meant that zeppelins could easily escape it by ditching ballast and climbing rapidly. The design speed had been 75mph (120kph) which was considered fast enough to catch zeppelins (though some zeppelins could go faster than that in favourable conditions) but it is reported the PB 31E struggled to pass 60mph (97kph).
The PB 31E first flew in February 1917 but by then it was apparent there were serious flaws in the concept, highlighted by the PB 31E's poor performance. Unable to pursue a zeppelin it's only chance of success would have been the sheer luck of being in the right place at the right time and firing on the zeppelin before it got out of range. It's main armament, a 1½ pounder Davis non-recoil gun, was also rather unwieldy.
The sole PB 31E was scrapped in the Summer of 1917, the second planned example never being built. The PB 31E, which was given the name Night Hawk, was technically innovative and it's concept could maybe have worked with more powerful engines and better performance. In the event the zeppelin was near the end of it's time as a military weapon in any case.
