When Pemberton-Billing Ltd changed its name to
Supermarine Aviation in December 1916, work on a
further airship fighter, the P.B.31E, had reached an
advanced stage and the first prototype of this quadruplane
was to fly shortly afterwards, in February 1917.
Fundamentally an extrapolation of the P.B.29E, and unofficially
known as Night Hawk, the P.B.31E was designed
to have a maximum endurance in excess of 18
hours to enable it to lie in wait for intruding airships.
The entire concept was fallacious as, in the unlikely
event that the P.B.31E found itself fortuitously in the
same area of sky as its prey, it would have been totally
incapable of pursuing the airship which could have
risen out of range before any guns could have been
brought to bear. A three-bay quadruplane powered by
two 100hp Anzani nine-cylinder radials, the P.B.31E
carried a searchlight in the extreme nose. The intended
armament comprised a one-and-a-half pounder Davis gun on a traversing mounting in a forward position
level with the top wing, a 7.7mm machine
gun being located in a second position immediately aft
and a similar weapon occupying a forward fuselage
position. Shortly after the start of flight trials, the shortcomings
of the concept were finally appreciated, and,
on 23 July 1917, the first prototype was scrapped and
the second incomplete prototype abandoned.
|A three-view drawing (1278 x 930)|
| Take-off weight||2788 kg||6147 lb|
| Empty weight||1668 kg||3677 lb|
| Wingspan||18.29 m||60 ft 0 in|
| Length||11.24 m||37 ft 11 in|
| Height||5.40 m||18 ft 9 in|
| Wing area||89.37 m2||961.97 sq ft|
| Max. speed||121 km/h||75 mph|
|J Kn, iohannkn=hotmail.com, 11.10.2011|
It's very steampunk.
|frank frinak, ffrinak=yahoo.com, 24.05.2011|
first and only quadraplane? Did it make take off? Any history of flight performance?
Do you have any comments about this aircraft ?
FACTS AND FIGURES
© The inadequately sized
rudders were mounted
between dual tailplanes,
probably to give a
greater field of fire for
the rear-racing guns.
© The extreme nose of the
PB.31E contained a
searchlight for finding
Zeppelins at night. In reality
it would have just given the
airship captains a head start.
© Not obvious in most
photos of the Nighthawk is
the narrow chord of the
four wings and the
considerable sweepback of
their outer sections.