The AD Flying Boat, designed by the British Admiralty’s Air Department, was intended to serve as a patrol aircraft in coordination with Royal Navy warships.
Although it was meant for use during the First World War, its production ceased as the war drew to a close, resulting in minimal operational use.
After the war, Supermarine Aviation repurchased several units and converted them into civil transports, under the name Supermarine Channel.
The aircraft, designed by Lieutenant Linton Hope in 1915, featured a conventional biplane flying-boat design and a biplane tail with dual rudders.
The pilot and observer were seated in tandem at the front, with the engine and pusher propeller positioned behind them, nestled between the wings.
The wings were designed to fold forward, simplifying storage aboard ships.
Pemberton-Billing Ltd, which would later evolve into Supermarine Aviation, constructed two prototypes in 1916.
The initial prototype was designed to be equipped with a 150 hp (112 kW) Sunbeam Nubian engine; however, due to its unavailability, the Hispano-Suiza 8 was used as a replacement.
The aircraft exhibited poor handling both on water and in flight, with significant fore and aft vibrations, termed ‘porpoising’, during take-off, and it was prone to excessive yaw while flying.
The issues were ultimately resolved with modifications to the hull, fin, and rudder, leading to the production order of the AD Flying Boat.
Out of an initial order for eighty, twenty-seven production models were constructed, typically equipped with 200 hp (149 kW) Hispano-Suiza engines, though some were tested with Sunbeam Arab and Wolseley Python engines.
After the Armistice, Supermarine reacquired nineteen aircraft to convert them for civilian use as the Supermarine Channel.
Specifications
Crew
Two: pilot and observer
Length
30 ft 7 in (9.32 m)
Upper wingspan
50 ft 4 in (15.34 m)
Lower wingspan
37 ft 7 1⁄4 in (11.462 m)
Height
13 ft 1 in (3.99 m)
Wing area
479 sq ft (44.5 m2)
Empty weight
2,508 lb (1,138 kg)
Gross weight
3,567 lb (1,618 kg)
Powerplant
1 × Hispano-Suiza 8,
Water-cooled V8 engine,
200 hp (150 kW)
Performance
Maximum speed
100 mph (160 km/h, 87 kn) at 2,000 ft (610 m)
Endurance
41⁄2 hr
Service ceiling
11,000 ft (3,400 m)
Time to altitude
30 min to 10,000 ft (3,050 m)
Armament
Guns
1 × .303 in (7.7 mm) Lewis gun on flexible mount for observer
Bombs
Small bombload
Sources
British Aeroplanes 1914–18-J M Bruce.
British Flying Boats-P London.
Supermarine Aircraft Since 1914-C F Andrews, E B Morgan.
