The aircraft was originally the design of Lt. G.H. Millar, of the RNAS Experimental Flight at Eastchurch, in response to a War Office requirement for a lightweight single-seat airship interceptor.
The design requirement called for a small, light aircraft that could take-off from a lighter towed behind a destroyer. This was not a new concept, it had been tried with existing fighters and it had been established it was feasible, however it was thought a purpose designed fighter would be a better option. The deployment was to be for the warship and its towed lighter to patrol in the North Sea, and when enemy airships were detected, the aircraft would take-off and shoot down the airship.
What was not covered in the concept was what happened to the aircraft afterwards. If it was within 100 miles of ‘home’ it would probably get there if the winds were favourable, other wise ditching close to the warship was the other alternative.
The P.V.8 was partially built at the Eastchurch establishment, but was completed at the Port Victoria workshops, on the Island of Grain.
The other competitive design created in response to the requirement was built solely at Port Victoria and designated P.V.7.
To differentiate between the two ‘Kittens’, the P.V.7 (N 538) was named the ‘Grain Kitten’ and the P.V.8 (N 540) the ‘Eastchurch Kitten’
The P.V.8 is best described as an angular, single bay staggered biplane, and it was intended to be powered by the 45 HP geared ABC Gnat engine. Armament was a single Lewis gun mounted on a mobile mounting over the upper wing, set to starboard of the propeller arc. The fuselage is ply covered from the engine bay back, with alloy engine cowls. The wings are of thin, cambered profile, possibly RAF 15 or similar, fabric covered, with ailerons on both sets of wings. The top wing has dihedral (the lower wing is straight) and is staggered forward, with only 1/3 cord overlap. There is a single “I” interplane strut. The fixed portion of the tailplane is covered with thin ply. The fin, rudder and elevators are fabric covered.
The under-carriage was unsprung, and provided the lower rigging point for the top wing flying wires. The lower wing drag wires attached to the engine bay bulkhead. The landing wires attached to the upper ends of the rear cabane strut. From the top of the interplane strut there were rigging wires back to a point about half way between the cockpit and the fin to hold the top planes in position by countering the forward thrust of the highly angled strut.
The 45 HP version of the Gnat engine failed to materialise, and the aircraft first flew with the 35 HP un-geared version of the power plant. The Gnat is a 2 cylinder horizontally opposed, air-cooled unit, and on the un-geared version the propeller spun anticlockwise when viewed from the pilots’ seat.
The P.V.8 first flew on September 1, 1917, and initially had no fixed tail plane, but after the first flight, the empennage was redesigned to incorporate a small area of fixed tailplane.
Although it proved to be far superior to the P.V.7 in all aspects, however it suffered from the installation of the 35 HP engine and never achieved the intended performance.
By the time the design had been finalised, the threat from airship raids over England had passed, and with it the requirement for the aircraft to intercept and destroy them.
The design must have had some merit, for on March 13, 1918 the aircraft was crated for shipment to the USA for evaluation, but there is no record of it ever having arrived ‘State side’.
The specifications for the P.V.8 (as designed) are as follows:
Max speed at 2000 ft 94 mph
Time to 6500 ft 11.0 mins
Empty weight 340 lb
Loaded weight 585 lb
Span (upper and lower) 18 ft 11.5 in
Wing area 106 sq ft
Length 15 ft 7.5 in
Height 5 ft 2 in.
Armament Single .303 Lewis machine gun
It is probably fitting to mention the brief career Lt. Millar. From what I can deduce from a search of War Memorial records, He joined the RNVR in September 1914, previously working at the National Physical Laboratory since 1910 as an assistant on the ship tank. He seems to have got straight into the action, being taken prisoner at Antwerp in October 1914, escaping a year later back to England. He received a commission as a Lieutenant in the RNAS in April 1916, and was attached to HMS Furious and seems to have been seconded to the Eastchurch experimental flight of the RNAS from about that time. As we know his design of the P.V.8 flew in September 1917. At some point he was promoted to Captain prior to his death in a flying accident on April 29, 1918.