burger-menu
Поиск по сайту:
airplane photo

Страна: Великобритания

Год: 1916

Летающая лодка

Варианты

C.Andrews, E.Morgan Supermarine Aircraft since 1914 (Putnam)

The A.D. Designs

  After the departure of Pemberton Billing for pastures new, which seems a novel way of describing the House of Commons, the Supermarine Works concentrated on working directly for the Admiralty, under Hubert Scott-Paine as managing director. The new company had been registered as the Supermarine Aviation Works Limited on 20 September, 1916. Meanwhile its contract for fifteen Short Type 184 floatplanes was running down and the twenty P.B.25s and the NightHawk were being completed. New work of a progressive nature was required and this was forthcoming from Air Department original designs, as well as Admiralty contracts for rebuilding aircraft returned from war service for repair.
  These A.D. concepts had managed to escape the Government embargo placed on original design by the Royal Aircraft Factory. This curious anomaly of history has never been explained. The principle of what is sauce for the goose is sauce for the gander was overlooked and the matter was probably an instance of lack of co-ordination in the whole war effort at the time, until a new Prime Minister started to take things in hand as in the Second World War. In any event, the Admiralty had been far more successful in their procurement policy than the War Office. The Handley Page heavy bomber, the Rolls-Royce Eagle engine and the range of Sopwith combat aircraft were originally naval requirements, a telling point not missed by Pemberton Billing and C. G. Grey in their attacks on the official aviation policy.
  So the Admiralty continued to foster its small but highly sophisticated Air Department which undoubtedly made a great impact on aircraft design, particularly in regard to structures. The mandatory manual Av.P. 970, entitled Design Requirements for Service Aircraft, owes its origin to the little booklet Handbook of Strength Calculations by Sutton Pippard and Laurence Pritchard on the basics first evaluated by Harris Booth and Harold Bolas and known as HB2, which were mathematically clarified by Arthur Berry into the famous Berry Functions. All these notable people were on the Air Department staff at the time of this break-through in airframe stressing.
  The concepts of the Air Department which were contracted to Supermarine consisted of the types known as the A.D.Boat, already in hand by Pemberton Billing Limited, the A.D.Navyplane and the N.1B Baby, the first British singleseat fighter flying-boat. After a shaky start to its career caused by hydrodynamic instability, the A.D.Boat was produced in small numbers, some of which were converted into civil passenger aircraft after the war. The Navyplane remained the sole example built at Woolston, largely because of engine supply shortages at the time, but the one Baby completed led to the Supermarine Schneider flying-boats.
  The two A.D.Boat prototypes, 1412 and 1413, were already being flight tested at the time the new company was finally constituted. According to J. Lankester Parker, who flew the type at an early stage, it suffered from the same malaise that plagued other seaplane designs at the time, particularly those in the flying-boat class, its chronic porpoising on take-off. In addition, the A.D.Boat had marked yaw defects, so much so that at take-off the machine had to be pointed downwind and, as planing speed rose, edged crabwise round into the wind. One of the principal causes of directional instability was thought to be the small area of the fin and rudder which characterized the Booth/Bolas designs. Strangely enough, the Supermarine Schneider racing floatplanes of a later date had a similar take-off problem for an entirely different reason.
  The overall designer of the A.D.Boat was Harris Booth, while Harold Bolas, Clifford Tinson and Harold Yandall were seconded from the Admiralty to Woolston Works to draft the details. Linton Hope was responsible for the lines and structure of the hull, the main attribute of which was its flexibility, enabling it to withstand the shocks and bumps of rough seas. On the circular hooped frames was a skin formed on a mould from double diagonal mahogany planking laid crosswise, with fabric sandwiched between the layers. The curved ribs of 1/4 in rock elm were closely spaced as were the stiffened stringers.
  This type of wooden construction stood the test of time until metal hulls were introduced by which time the hydrodynamic problems of planing bottoms had been largely solved. Those of the A.D.Boat were indicative of the search for knowledge on the subject, on which the experts could not agree, including G. S. Baker, who operated the Walter Froude model water-testing tank at the National Physical Laboratory. He had visited all the marine aircraft bases and was said to be the authority on matters like lift-off, hump speeds, angle of attack, shape and location of steps, and so on. The whole picture can be envisaged by a study of Linton Hope’s own Paper on Notes on Flying Boat Hulls which appeared in the Aeronautical Journal of the Royal Aeronautical Society for August 1920. The controversies of the time were clearly brought out in the discussion which followed the presentation of the Paper.
  So after juggling with the location of the main step and changing the rear step from a streamline shaped tail to square cut, the A.D.Boat finally became a practical proposition for sea patrol duties although its actual use seems limited. The first production machine, N1520, passed acceptance trials at the Isle of Grain on 5 September, 1917. As with other new aircraft types at the time, the A.D.Boat suffered the usual set-backs caused by the erratic supply of satisfactory engines. It was designed for the Sunbeam Nubian, which failed to reach requirements. Hispano-Suizas were fitted, both direct-drive and geared, the latter having trouble with its gearing as it did in the S.E.5a. Later on, the Wolseley Python and Viper and the Sunbeam Arab were fitted experimentally, apparently with better results but only when the useful employment of the type was past. Production aircraft totalled 27 but most went into store. N1712 and N1719 were sent to Isle of Grain naval air station for experimental use, the latter being fitted with hydrovanes and flown in this form by Harry Busteed and Bentley Dacre. After the war N1529 was the first A.D.Boat to be converted by Supermarine as a civil passenger-carrying aircraft, and the further use of the new type, known as the Channel, is dealt with later.
<...>


A.D.Boat - One 200 hp Hispano-Suiza. Pilot and observer.
   Span 50 ft 4 in (15-34 m); span folded 14 ft (4-26 tn); length 30 ft 7 in (9-32 m); length folded 42 ft 3 in (12-87 m); height 13 ft 1 in (3-98 m); wing area 455 sq ft (42-27 sq m).
   Empty weight 2,508 lb (1.137 kg); loaded weight 3,567 lb (1,618 kg).
   Maximum speed 100 mph (160-9 km/h); alighting speed 46 mph (74km/h); duration 4 1/2 hr.
   Armament. One 0-303-in Lewis machine-gun in bow cockpit.

Показать полностью

Описание:

  • C.Andrews, E.Morgan Supermarine Aircraft since 1914 (Putnam)
  • G.Duval British Flying-Boats and Amphibians 1909-1952 (Putnam)
  • J.Bruce British Aeroplanes 1914-1918 (Putnam)
  • O.Thetford British Naval Aircraft since 1912 (Putnam)
  • H.King Armament of British Aircraft (Putnam)
  • Jane's All The World Aircraft 1919