A.Jackson Avro Aircraft since 1908 (Putnam)

Avro 536

  Reference has been made in previous chapters to a unique batch of civil aircraft built in the Hamble works between April and November 1919. To satisfy the enormous demand for pleasure flights, the Avro Transport Company simply had to provide more seats and quickly. The problem was solved by giving some of these Hamble 504K variants a nine-inch increase in width to enable four passengers to sit in side by side pairs in the rear cockpit. Each occupant had his own individual windscreen, the rear windscreens being fixed to a strip of decking hinged to the starboard top longeron for ease of entry. In this form, as the Avro 536, the machine was a short-range five-seater and (as in the case of Avro 504Ls from the same production batch), extra take-off power at the higher all-up weight was given by a 150 hp Bentley B.R.l.
  The Avro 536 was easily distinguishable from the 504K since the extra nine inches of width resulted in an obvious difference in the spacing of the centre section struts. Having a tricolour rudder, but no other markings apart from AVRO in large white letters, the prototype first flew at Hamble in April 1919, one of the first passengers being the Lord Chancellor who flew in it with H. A Hamersley on the 25th of that month. Seven production 536s which followed plunged immediately into the fray at southern joyriding sites: K-104 and K-105 at Hounslow Heath; K-116 and K-137 at Southsea; K-161 at Weston-super-Mare; and K-166 at Margate. K-165 is believed to be that sent to the First Air Traffic Exhibition at Amsterdam. A batch of 12 was also put in hand at Manchester but only seven of these were certificated in time to earn money in 1919. Whereas the constructor’s numbers of the Hamble batch were prefixed A.T.C. (Avro Transport Company), those built in Manchester were initialled B for Blackpool where three pilots carried 500 passengers in 536s on the day of their introduction.
  All Avro 536s had the 504L-type fin to offset the torque of the powerful Bentley rotary except the first three production aircraft, two of which were involved in serious accidents. Capt H. R. Hastings was killed when K-105 stalled on approaching Sandhurst at the end of a charter flight from Hounslow on August 6, 1919; and Capt E. A. Sullock, on direct track from Hounslow to Southend with two passengers on September 9, suffered engine failure over Rotherhithe and put K-104 down in Southwark Park where it broke its back. A third Avro pilot, Brig-Gen C. F. Lee CMG, who had demonstrated the 504J C4312 at Washington in 1917, was killed when the fin-equipped K-161 stalled when coming in to land on Weston-super-Mare sands in the same month.
  Unlike other Avro 536s, the prototype boasted a large aerofoil-shaped centre-section fuel tank and after a few trial flights at Hamble, was fitted with floats and extended fin to become the sole 536 seaplane. It retained the tri-colour rudder and on July 2, 1919, began a joyriding season in the Isle of Wight as K-114. The pilot was Capt F. Warren Merriam who flew A. V. Roe daily to and from Hamble while he was on holiday in the island and, assisted by a 504L, completed a two months’ lucrative season at Ryde, Sandown, Shanklin and Ventnor. The last two Hamble-built 536s were special aircraft; K-139/G-EADV was a two-seater with large fuselage fuel tank for experimental work or long-distance competition flying, and the other (23rd and last machine on the mixed production line) was converted into a cabin type known as the Avro 546 for three passengers and pilot. Main differences between this aircraft and the contemporary Avro 504M lay in the widened fuselage, open pilot’s cockpit, squarish windows below the top longeron and the Bentley B.R.1 engine. Registered G-EAOM, the Avro 546 saw little service and only made a few flights at Hamble and West Blatchington Farm, Brighton, early in 1919-20.
  When the Avro Transport Company ceased operations a few of its former pilots hired 536s and carried on in 1920 but all eventually returned to Alexandra Park for storage. Four from the tail end of the production line (G-EAKM-’KP), completed too late to be used commercially, were also stored. In 1923 F. J. V. Holmes bought ’KN for use by Berkshire Aviation Tours Ltd and in 1925 ’KJ, ’KM and ’KP were acquired by Surrey Flying Services Ltd to take over joyriding from their aged 504Ks.
  Bentley rotaries were no longer in service in 1925 and the Surrey Avro 536s were fitted with Clergets. With reduced fuel loads they were very economical indeed, carrying pilot and four passengers quite satisfactorily on the company’s famous 5 minute/5 shilling ‘flips’. Low power also made the dorsal fin unnecessary and in 1926-27 the firm erected four additional Avro 536s G-EBOF, ’OY, ’RB and ’TF, for which no original construction details were recorded. They were evidently the best of the airframes still remaining in store and the unexplained constructor’s number P.8 given for G-EBOY is believed to be a corruption of B.8, identifying it as the former G-EAKL. They seldom ventured far afield, although G-EBOY gave joy flights from the beach at Jersey in 1927 and during a barnstorming tour in 1928 ’RB was used extensively for wing walking exhibitions.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Newton Heath, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Avro 536)
   One 130 h.p. Clerget
   One 150 h.p. Bentley B.R.I
   (Avro 546)
   One 150 h.p. Bentley B.R.I
   Dimensions:
   Span 36 ft. 9 in.
   Length 29 ft. 5 in.
   Height 10 ft. 5 in.
   Wing area 335 sq. ft.
   Weights:
   Tare weight 1,431 lb.
   All-up weight 2,226 lb.
   Performance:
   Maximum speed 90 m.p.h.
   Cruising speed 70 m.p.h.
   Initial climb 550 ft./min.
   Ceiling 12,000 ft. Range 190 miles
Note: The above figures apply to both Avro 536 and 546.