A.Jackson Avro Aircraft since 1908 (Putnam)

Avro 501 and Avro 503 (Type H)

   The choice of Shoreham as the Avro company's new flying ground when it moved from Brooklands in the autumn of 1912 was largely the result of Cdr. Schwann's successful waterborne experiments and Avro's awakening interest in seaplanes. It was an ideal site with Shoreham Harbour close at hand and it was from the adjacent River Adur that the Avro Type H seaplane made its first take-off. Construction of this machine followed tests on Windermere by H. Stanley-Adams in January 1913 with the Avro 501 which, apart from a considerable strut-braced top wing overhang, was similar to an enlarged float-equipped Avro 500. Built at Brownsfield Mills in November 1912 and powered by a 100 h.p. Gnome, the Avro 501 first flew as an amphibian with a sprung central float designed by O. T. Gnosspelius, 15 ft. long and 7 ft. wide from which projected three small wheels, two in the rear and one forward. With so narrow a float an aircraft with a wing span of 47 ft. 6 in. could be expected to heel over when steerage way was lost, and for this reason small wing tip floats were fitted and inclined to sit squarely in the water. This arrangement proved unsatisfactory and Gnosspelius replaced it with a twin float unit without wheels which made the aircraft sufficiently seaworthy to interest the Admiralty, to whom it was eventually delivered in the Isle of Grain. In the light of experience at Barrow, the airscrew leading edges were sheathed with brass to prevent damage from flying spray and the tail float was bolted directly to the old-style sprung rudder for steering on the water.
<...>
   The float undercarriage of the old Avro 501 having proved far too heavy, the Admiralty agreed to accept it as a landplane. A. V. Roe thereupon devised a two-wheel, twin skid undercarriage but the track was still too narrow to support the aircraft vertically at rest and stout wing tip skids were necessary. In landplane form, with large inversely tapered ailerons replacing the constant chord units, the Avro 501 was so quaint a structure that it soon earned the name "Rickety Ann". After delivery to Eastchurch it had to be lightened and several airscrews tried before F. P. Raynham could complete the acceptance tests. Bearing naval serial 16 it was flown to Shoreham on June 2, 1913 by Raynham with Lt. Seddon as passenger.
   In the course of R.N. A. S. trials by F. P. Raynham at Eastchurch on August 28, 1913 a second landplane climbed to 3,000 ft. in 19 minutes with 36 gallons of petrol, 10 gallons of oil and 182 lb. of ballast. In the speed test 65.1 m.p.h. was reached and this aircraft, last of those ordered from A. V. Roe before the firm became a limited company, was followed by a float-equipped example which arrived at Sheerness in crates on September 8, 1913. On October 15 it was handed over to the R.N.A.S. in the Isle of Grain where it was joined eventually by an improved version built in the following December. One of these machines was damaged in a hangar fire at Eastchurch and sent to Brooklands for repair in July 1914.

SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company (reconstituted as A. V. Roe, and Co. Ltd. 11.1.13), Brownsfield Mills, Great Ancoats Street, Manchester (moved to Clifton Street, Miles Platting, Manchester 4.13); and Shoreham Aerodrome, Sussex
   Power Plant: One 100 h.p. Gnome
   Dimensions, Weights and Performances:
   Avro 501 seaplane
   Span (upper) 47ft. 6 in.
   Span (lower) 39ft. 6 in.
   Length 33ft. 0 in.
   Height 12ft. 6 in.
   Wing area 478 sq. ft.
   Tare weight 1,740 lb.
   All-up weight 2,700 lb.
   Maximum speed 55 m.p.h.*
   *Landplane 65 m.p.h.

   Production:
   Avro 501 seaplane, first flown on Windermere 1.13, converted to landplane serial 16, still airworthy in 1914
   At least one other landplane to R.N.A.S. Eastchurch and two seaplanes to R.N.A.S. Isle of Grain

O.Thetford British Naval Aircraft since 1912 (Putnam)

AVRO 501

   Avro's first seaplane, produced in January 1913. One only supplied to RNAS as No.16, was converted from amphibian to a landplane and flown at Eastchurch Naval air station, where it was used for training. One 100 hp Gnome engine and a loaded weight of about 2,200 lb. Span, 50 ft. Length, 33 ft 6 in.

M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)

P.Lewis British Aircraft 1809-1914 (Putnam)

Avro Hydro-biplane

   The Avro company delivered one two-seat tractor biplane, built to an Admiralty order, to Eastchurch during December, 1912, for testing by H. Stanley-Adams. The machine was fitted with a single large central float which had been designed by Oscar T. Gnosspelius; wheels were attached to it to form an amphibian. The engine was the 100 h.p. Gnome. Span, 47 ft. Length, 33 ft. Wing area, 478 sq. ft. Weight empty, 1,740 lb. Weight loaded, 2,700 lb. Maximum speed, 55 m.p.h. Duration, 6 hrs.