A.D. AD.1 Navyplane
F.Manson British Bomber Since 1914 (Putnam)
Air Department A.D.I Navyplane
It is sometimes said that Harold Bolas, in effect deputy chief designer at the Admiralty's Air Department, saw part of his job as exerting a restraining influence on the wilder excesses of his immediate senior, Harris Booth. Yet it should be remarked that, although most of Booth's own designs bordered on the grotesque, he was able to use his undoubted influence with the Board of Admiralty when it came to gaining official support for the designs of his subordinates (and he it was who strongly advised Murray Sueter to have such outstanding aeroplanes as the Handley Page O/100, and Sopwith 1 1/2-Strutter, Pup and Camel adopted by the Admiralty when they were still on the drawing board).
It fell to Harold Bolas to initiate the design early in 1916 of a reconnaissance/bombing seaplane, officially designated the A.D.I, but generally referred to as the Navyplane. As the Air Department's Experimental Construction Depot at Port Victoria, Isle of Grain, was not yet fully equipped to undertake the building of complete aeroplanes, the initial A.D.I design was handed over to the Supermarine Aviation Works at Woolston, Southampton, for the detail design to be completed and construction of a prototype. Working in close collaboration with Bolas, Reginald Mitchell finished the necessary manufacturing drawings in an exceptionally short time, and the prototype, No 9095, was ready for testing by Cdr John Seddon in August.
The A.D.I was a compact two-bay biplane whose two-man crew was accommodated in a finely-contoured lightweight monocoque nacelle located in the wing gap, the experimental air-cooled 150hp Smith Static radial engine driving a four-blade pusher propeller. Twin pontoon-type floats were braced to the nacelle and to the lower wings immediately below the inboard interplane struts. Twin fins and rudders were carried between two pairs of steel tubular tail booms, and the tailplane was mounted above the vertical surfaces. Twin tail floats, each with a water rudder, were attached beneath the lower pair of tail booms. The pilot occupied the rear cockpit, with the observer in the bow position. Two 100 lb bombs were to be carried under the wing centresection.
The ten-cylinder Smith engine, brainchild of an American John W Smith, had evidently attracted the Admiralty's interest, and had shown promise during bench testing. A production order was placed with Heenan & Froude Ltd, but the engine never gave satisfactory performance in the few prototype aircraft in which it was flown.
Little more was heard of the A.D.I until May 1917, when it re-appeared with by an A.R.I engine, designed by W O Bentley. However, although this engine displayed much improved reliability, the A.D.I's performance remained below that demanded by the Admiralty, and six further aircraft originally ordered were not built.
Supermarine had made some efforts to continue development of an enlarged version of the A.D.I, called the Submarine Patrol Seaplane, powered by a 200hp engine, and submitted the design to the Air Board's Seaplane Specification N.3A. Although two prototypes were allotted the serial numbers N24 and N25, work on the project was discontinued when it was decided that the veteran Short Type 184 adequately met the requirements and would continue in service. (In any case the Supermarine aircraft would have been unable to lift the 1,100 lb 18 in torpedo, and did not possess folding wings - both requirements of N.3A.)
Type: Single pusher engine, two-seat, two-bay reconnaissance-bomber biplane with twin main-float undercarriage.
Manufacturer: The Supermarine Aviation Works Ltd, Woolston, Southampton, Hampshire, under the design leadership of Harold Bolas of the Air Department, Admiralty.
Power plant: One 150hp Smith Static ten-cylinder, single-row, air-cooled radial engine driving four-blade pusher propeller; later replaced by a 150hp A.R.I (Admiralty Rotary)
Dimensions: Span: 36ft 0in; length, 27ft 9in; height, 12ft 9in; wing area, 364 sq ft.
Weights (Smith Static engine): Tare, 2,100 lb; all-up, 3,102 lb.
Performance: Max speed, 75 mph at 2,000ft; endurance, 6 hr.
Armament: Provision for one 0.303in Lewis gun on rotatable mounting in nose of nacelle. Provision for bomb load, probably not exceeding 200 lb.
Prototype: One, No. 9095, first flown with Smith Static engine by Lt-Cdr John Seddon RN, in August 1916. Second aircraft. No 9096, was cancelled, as was a batch of five aircraft, N1070-N1074.
P.Lewis British Bomber since 1914 (Putnam)
Although, as a general design layout, the pusher type of aircraft carrying its tail unit on booms had largely been eschewed by the middle of the 1914-18 War, it was still considered effective enough to be employed in the two-seat A.D. Navyplane which Supermarine built in 1916 for the Air Department of the Admiralty. Overall, the 36 ft. span biplane resembled strongly the Supermarine Patrol Seaplane. R. J. Mitchell and a fellow Supermarine designer, Richardson, co-operated in the project with the Admiralty’s Harold Bolas, whose product the design was. The single prototype, 9095, employed two-bay, unstaggered wings of 36 ft. equal span, in the centre of which a lightweight monocoque nacelle with tandem seats was supported by struts. A flexibly-mounted Lewis gun armed the observer’s cockpit. Twin pontoon main floats were augmented by a smaller pair borne at the rear by the booms.
9095’s first engine, with which Lt. Cdr. J. W. Seddon conducted the Navyplane’s first flights during August, 1916, was the ten-cylinder, single-row 150 h.p. Smith Static radial. This was later replaced by the 150 h.p. Bentley A.R.1 rotary in which form 9095 underwent further trials in May, 1917, but its relatively low overall performance precluded its production as a reconnaissance or bomber aircraft.
J.Bruce British Aeroplanes 1914-1918 (Putnam)
THE Navyplane was a two-seat pusher biplane floatplane sponsored by the Air Department of the Admiralty in 1916, and intended for reconnaissance and bombing duties. It was designed by Harold Bolas of the Air Department in collaboration with Messrs R. J. Mitchell and Richardson of the Supermarine Aviation Works, Ltd., to which company the construction of the machine was entrusted.
Eight weeks after the drawings were received by the Supermarine company the Navyplane was completed, an achievement which brought the manufacturers a letter of appreciation from Commodore Murray F. Sueter. Serial numbers were allotted for seven machines but only one was built. The Navyplane’s test flights were carried out in August, 1916, by Lieutenant-Commander John Seddon.
Structurally the Navyplane was a two-bay biplane with the tail unit supported on four tail-booms, and its most remarkable feature was its monocoque nacelle which, complete with seats and floor-bearers, weighed no more than 80 lb. The nacelle had a sectional glass screen which was led round the nose from the forward windscreen to a point under the pilot’s seat; this gave the crew a good forward and downward view. The Navyplane carried wireless, and the observer had a Lewis gun on a special flexible mounting. The nacelle was mounted mid-way between the wings. The wings themselves were made in three parts and only the outer portions were rigged with dihedral. The tailplane was attached to the upper tail-booms and was of the inverted camber type.
The main floats were pontoon structures and were connected horizontally by only one cross-bar. Each of the twin tail-floats had a water-rudder.
The Navyplane’s original power-plant was a new type of radial engine, the 150 h.p. Smith Static. The design of this engine was brought to England in January, 1915, by an American, John W. Smith, who succeeded in interesting the Admiralty in it almost immediately. The Smith Static was a ten-cylinder single-row radial engine which had offset connecting rods bearing alternately on the cranks of a two-throw crankshaft. The engine must have been reasonably successful. It was tested on the bench and in the air to the satisfaction of the Admiralty. A contract for its production was given to Messrs Heenan & Froude, but only a few were delivered before the Armistice.
The Smith engine was installed quite neatly in the A.D. Navyplane but was later replaced by a 150 h.p. A.R.I. rotary engine. The reason for the change is uncertain, but difficulty may have been experienced with the cooling of the radial. With the A.R.I engine the Navyplane was tested in May, 1917, but with no military load and no observer the performance was very poor.
Manufacturers: The Supermarine Aviation Works Ltd., Woolston, Southampton.
Power: 150 h.p. Smith Static radial engine; later, 150 h.p. A.R.I rotary engine.
Dimensions: Span: 36 ft. Length: 27 ft 9 in. Height: 12 ft 9 in. Chord: 5 ft. Gap: 6 ft 6 in. Stagger: nil. Span of tail: 15 ft 6 in. Airscrew diameter: 8 ft 10 in.
Areas: Wings: 364 sq ft.
Weights (lb) and Performance:
Engine Smith Static A.R.I
Date of Trial Report - 15 May, ’9'7
Weight empty 2,100 2,042
Military load - nil
Crew - 180
Fuel and oil - 328
Weight loaded 3,102 2,550
Maximum speed (m.p.h.) at 2,000 ft 75 64-5
Climb to 2,000 ft - 30 min
Service ceiling (feet) - 1,300
Endurance (hours) 6 6
Armament: One Lewis machine-gun on a movable mounting for the observer.
Serial Numbers: 9095-9096. (9096 was not built.) N.1070-N.1074: cancelled.
H.King Armament of British Aircraft (Putnam)
A.D. Navyplane. Built in 1916 for the same duties as the A.D. Flying Boat, the Navyplane twin-float seaplane had a pillar-mounted Lewis gun in the nose of the nacelle and provision for a small bomb load. In later years Maj T M. Barlow, who was well acquainted with this aircraft, with gun-mounting development generally, and with the Fairey "High-Speed" mounting in particular, said that the mounting was of 'movable, pivoted, traversing' type and was the 'forerunner of certain modern types'.
Jane's All The World Aircraft 1919
Pusher seaplane, built to Admiralty design, fitted with 130 h.p. Smith. This machine was completed and flying eight weeks after receipt of drawings. The nacelle is boat-built, with the lightest wooden construction known, the whole nacelle weighing 85 lbs.