H.King Sopwith Aircraft 1912-1920 (Putnam)
The 'Sopwith Kitten'
Although Commander Harry Busteed was at one time in charge of the RNAS Experimental Flight at Eastchurch, and - in the course of his work - also had a close relationship with the Sopwith company (being, in any case, one of the three original 'Aussie Harrys' together with Hawker and Kauper) there is scant reason to suppose that the name 'Sopwith Kitten' was justly applicable to the ship's ultra-light armed scout which was otherwise called the Port Victoria P.V.8 Eastchurch Kitten. The ascription might, nevertheless, have been fostered by structural features, the most obvious being the plank-type interplane struts. (The true designer was, it seems, Capt Gilbert Henry Millar, who, after a period as a prisoner of war, escaped. Millar had yachting experience, had joined the RNVR and was transferred successively to the RNAS and the RAF. Although he became a pilot himself, he served also as an observer with the Fleet).
The photograph herewith of the charming little aeroplane just mentioned is reproduced for two reasons - apart from the discredited name 'Sopwith Kitten' and from the fact that this particular picture appears not to have been previously published: (1) The photograph was given to the present writer by Sir Frank Spriggs, who was with Sopwith from 1913 to 1920, and later became managing director of Hawker Siddeley. Though received together with views of indubitable Sopwith types, this Kitten picture had no accompanying text. (2) This same photograph shows a tailplane of seemingly unfamiliar form, though one of another shape was apparently fitted after the aircraft had been initially flown with no horizontal fixed tail-surfaces whatever.
Yet another derivative of the Sopwith Baby was the one-off Port Victoria P.V.1, with wings of higher aspect ratio, heavily cambered and heavily staggered.
H.King Armament of British Aircraft (Putnam)
P.V.8 (Eastchurch Kitten). Built to meet the same requirements as the P.V.7, the P.V.8 had its Lewis gun offset to starboard. This type likewise had a cut-away trailing edge to allow elevation, though it was officially reported that the gun would be awkward to fire because of the pilot's cramped position.
P.Lewis The British Fighter since 1912 (Putnam)
The next designation in the Port Victoria design series, P.V.6, was allotted to an uncompleted project for a fast scout landplane. Attention was next turned to meeting a call for a very small, low-powered scout capable of being flown from minor warships. The engine specified was the two-cylinder, geared 45 h.p. A.B.C. Gnat. Besides the Port Victoria Depot, the Experimental Flight at Eastchurch was asked also to submit a design.
Each machine was a diminutive biplane, that designed at Port Victoria being designated the P.V.7, while the Eastchurch-conceived machine, through transference to Port Victoria for completion, became the P.V.8. Respectively, the aircraft were called the Grain Kitten and the Eastchurch Kitten.
Both types constituted early examples of the often-attempted light fighter, each being a well-conceived and competent approach to an interesting challenge.
Grain’s P.V.7 was the smaller of the two, following the normal layout for a single-seat, single-bay biplane of unequal span and showed traces in its outline of its predecessors from the same design source.
The Eastchurch Kitten was rather more angular and of cleaner cut than the Grain machine and received equal-span wings, set with accentuated stagger on single I-type interplane and centre-section struts.
Both the P.V.7 and P.V.8 were forced to use the lower output of the direct-drive 35 h.p. A.B.C. Gnat as the 45 h.p. version of the engine was not available. Each was armed with a single Lewis gun on the upper centre-section and each machine was modified in several respects after completion in mid-1917 and, of the pair, the P.V.8 showed itself to be the superior aeroplane.
F.Mason The British Fighter since 1912 (Putnam)
Port Victoria P.V.7 and P.V.8
Early in 1916 the Admiralty directed the Experimental Construction Depot at Port Victoria and the Experimental Flight at Eastchurch to examine the feasibility of producing a small scout capable of taking off from a very short platform aboard a Torpedo-Boat Destroyer, specifying the use of a geared 45hp ABC Gnat engine.
Both agencies produced independent designs, Capt W H Sayers rfc producing the P.V.7 at Port Victoria; at Eastchurch, Lieut G H Millar rnvr devised a rather different sort of aircraft. However, when Sqn Cdr H R Busteed moved from Eastchurch to assume command of Port Victoria, he took with him both Millar and his design, which was then designated the P.V.8. To differentiate between their design origins, the P.V.7 came to be called the Grain Kitten, and the P.V.8 the Eastchurch Kitten.
The P.V.7 was unquestionably the more attractive of the two, with sesquiplane wings, outward canted and paired interplane struts, gracefully tapering fuselage in plan and low aspect ratio ailerons on the top wing only. There was a spigot-mounted Lewis gun above the wing. However, tested first on 22 June 1917, the P.V.7 proved difficult to handle on the ground, and tail-heavy in the air; moreover the sesquiplane layout, with high-lift wings, was shown to be unsuitable for the tiny aeroplane.
By contrast, the aesthetically less-pleasing Eastchurch Kitten was much more successful. It featured heavily staggered single-bay wings of equal span employing I-form interplane and cabane struts from a crashed Sopwith Triplane, and when first flown on 7 September, it featured a balanced elevator without fixed tailplane. The pilot, Harry Busteed himself, reported severe longitudinal instability, with the result that a fixed tailplane was added, and much of the elevator horn balance was removed. To provide some shock absorption during landing, very big landing wheels with large-section tyres were fitted.
As with almost all Port Victoria’s aircraft, the engines promised for the two Kittens never materialised, and both aircraft had to be modified to take the direct-drive 35hp version of the ABC Gnat. This engine, designed by Granville Bradshaw, was an ingenious horizontally-opposed twin-cylinder aircooled engine weighing 115lb dry. Yet, despite the obvious success of the P.V.8, and the ease with which it could be flown, interest in the idea was shortlived.
Type: Single-engine, single-seat, single-bay lightweight biplane scout.
Manufacturer: RNAS Experimental Construction Depot, Port Victoria, Isle of Grain.
Powerplant: One direct-drive 35hp ABC Gnat horizontally-opposed two-cylinder aircooled engine.
Dimensions: P.V.7. Span, 18ft 0in; length, 14ft 11in; height, 5ft 3in; wing area, 85 sq ft. P.V.8. Span, 18ft Oin; length, 15ft 7 1/2 in; height, 5ft 5in; wing area, 106 sq ft.
Armament: Both aircraft equipped to carry one 0.303in Lewis gun above wing centre section.
Prototypes: P.V.7, N539 (first flown by H R Busteed on 22 June 1917). P.V.8, 540 (first flown by Busteed on 7 September 1917). No production.
W.Green, G.Swanborough The Complete Book of Fighters
PORT VICTORIA P.V.8 (EASTCHURCH KITTEN) UK
Although designed by Lt G H Millar of the RNAS Experimental Flight at Eastchurch and partly built by that establishment, this competitor for the P.V.7 as a lightweight single-seat interceptor was completed in the workshops at Port Victoria and assigned the designation P.V.8. Becoming known as the Eastchurch Kitten, the P.V.8 was an angular single-bay staggered biplane intended, like the P.V.7, to be powered by the geared ABC Gnat engine, but of necessity fitted with the 35 hp ungeared version of this two-cylinder power plant. When initially flown on 1 September 1917, the P.V.8 possessed no fixed tailplane, but the horizontal tail surfaces were redesigned to incorporate a small tailplane prior to the second flight. Proving itself superior to the P.V.7 in every way, the P.V.8 suffered similar problems with its engine. On 13 March 1918, the Eastchurch Kitten was packed for despatch to the USA, where it was to be evaluated, but there is no record that it ever reached its destination.
Max speed, 94 mph (151 km/h) at 2,000 ft (610 m).
Time to 6,500 ft (1 980 m), 11.0 min.
Empty weight, 340 lb (154 kg).
Loaded weight, 586 lb (266 kg).
Span, 18 ft 11 1/2 in (5,78 m).
Length, 15 ft 7 1/2 in (4,76 m).
Height, 5 ft 2 in (1,57 m).
Wing area, 106 sqft (9,85 m2).