Flight, July 1920

The Olympia Aero Show 1920

The machines

A.V. Roe and Co., Ltd. (STAND 63) Newton Heath, Manchester, and Hamble, Southampton.

   The Avro "Baby," fitted with a 35 h.p. Green engine, will probably draw the most attention, particularly as it is the machine on which Mr. Bert Hinkler recently made his marvellous non-stop flight from London to Turin. It is claimed that the Avro "Baby," which has been specially designed for the private owner who wishes to fly and attend to his machine, is less costly, more economical to run, and requires less attention than a motor-car, and Mr. Hinkler's performance goes far to justify the claim. The first machine of this type flew for over twenty hours without any adjustment, although it had been raced and "stunted," and made many cross-country flights. It also won the efficiency prize in the Aerial Derby last year.
   The "Baby" can be spun, looped, rolled, etc., to suit the most exacting "stunt" pilot's requirements, although at the same time, it is an exceedingly stable and safe machine to fly, and has a very low landing speed. The cockpit is roomy and comfortable and the pilot has an excellent view.
   The machine can be fitted with floats to make a sporting seaplane, and also can be supplied with a modified fuselage with seating accommodation for two. A full description of this machine appeared in FLIGHT for June 26, 1919.


The Avros

   The Avro Baby, which has already been fully described in FLIGHT (June 26, 1919) has to its credit some very fine performances, chief among which is, of course, the flight from London to Turin non-stop in 9J hours, piloted by Sir. Bert Hinkler. This furnishes a most convincing proof of the utility of a small machine, this flight having been made for a fuel expenditure of 20 gallons of petrol, or well over 30 miles to the gallon. This opens up vast possibilities of cheap aerial touring in the future, and proves that very high-power engines are not necessary for rapid locomotion. The details of the construction are already well known from previous descriptions in FLIGHT, and no further reference to them is necessary here.

Flight, November 1920

TWO-SEATER AVRO "BABY" BIPLANE, TYPE 543

   THIS aeroplane is a development of the little 35 h.p. single-seater Avro "Baby" biplane, type 543 - a full description, with scale drawings, of which appeared in FLIGHT for June 26, 1919 - which has put up such a remarkable series of performances during the last eighteen months, including 1st in Aerial Derby Handicap 1919, 1st and 2nd in Aerial Derby Handicap 1920, and non-stop flight to Turin, including crossing the Alps
   Except for the longer cockpit and the slightly further forward position of the engine, which has been so placed in order to balance the weight of the passenger, it will be seen that the two-seater "Baby" is practically identical with the single-seater "Baby."
   The following is a summary of the technical data of the two-seater Avro "Baby" :-
   Span of top plane 25 ft.
   Span of bottom plane 23 ft.
   Chord ot planes 4 ft.
   Gap between planes 4 ft. 3 in.
   Stagger of planes 1 ft. 6 in.
   Length overall 20 ft.
   Height overall 7 ft. 6 in.
   Span of tail-plane 7 ft. 6 in.
   Chord of tail and elevators 3 ft. 5 1/4 in.
   Area of planes and ailerons 176 1/2 sq. ft.
   Area of tail and elevators 22 1/4 sq. ft.
   Angle of incidence of planes 4 1/2 degs.
   Dihedral angle 3 degs.
   Weight bare (with water) 630 lbs.
   Weight loaded 970 lbs.
   Surface loading 5 1/2 lbs./sq. ft.
   Engine loading (40 h.p.) 24-2 lbs./h.p.
   Petrol capacity 8 galls.
   Oil capacity 1 1/2 galls.

   The following performances were obtained from the average of a number of carefully conducted test flights carried out at the Hamble Aerodrome, near Southampton :-
   Maximum speed (sea level) 82 m.p.h.
   Landing speed 40 m.p.h.
   Stalling speed 40 m.p.h.
   Cruising speed at 1,000 ft. 70 m.p.h.
   Petrol consumption cruising at 1,000 ft. 2 1/2 galls, per hr.
   Duration cruising at 1,000 ft. 3-2 hrs.
   Cruising range 225 miles.
   Climb to 1,000 ft. 2 1/4 mins.
   Climb to 2,000 ft. 4 1/2 mins.
   Climb to 5,000 ft. 13 mins.
   Climb to 6,600 ft. 18 1/2 mins.
   Climb to 10,000 ft. 35 mins.
   Ceiling 12,000 ft. in 50 mins.
   Maximum speed:
   Sea level 82 m.p.h.
   6,600 ft 77-5 m.p.h.
   10,000 ft. 72-5 m.p.h.
   From the above figures it will be seen this machine is very efficient, and the ease with which it can be landed in and flown out of small fields makes it particularly suitable for cross-country flying. The machine is reported as light and quick on the controls at high and low altitudes.
   It is claimed that it can be flown equally well without a passenger, and can perform all the "stunts" which are expected of modern aeroplanes.

Construction

   The undercarriage is of the "Vee" type with, a split axle, hinged in the centre. The chassis is entirely constructed of steel tube, faired off with light 3-ply fairings, which are, in turn, covered with linen, doped and painted. The wheels, fitted with Palmer cord tyres 600 by 50 mm., are sprung by the usual rubber shock-absorbers, while the track, 5 ft., is wide for such a small machine.
   The tail skid is made of ash, with a steel shoe, and is also sprung with rubber shock-absorbers.
   The planes are built up in the "Avro" manner, the main spars being of built-up box section with spindled wooden leading edge and tubular steel end sweeps and trailing edges. The ribs, of girder construction, are placed close together so as to retain a good wing form and R.A.F.15 Section. Small nose ribs are placed between each of the main ribs. Internal bracing is by means of high tensile steel wire and "Avro" turnbuckles. Compression struts are formed of strong box ribs, as in the standard "Avro" type.
   Only one pair of interplane struts is used on each side of the body, and the lift wires are splayed out so as to attach to the body over a wide length, this distributing the lift loads along the body and also assisting the internal bracing of the wings to take the drag loads. The centre section struts, which are splayed out in front view, are made of streamline section steel tube.
   The fuselage is built up on the conventional box girder system with spruce longerons and struts and steel wire bracing, "Avro" body sockets and strainers being employed. It is of ample proportions, and the cockpit is roomy for so small a machine. Two seats of the bucket type, with upholstered cushions, are fitted, and the engine and machine controls are conveniently placed, the engine control being on the pilot's left hand. A 3-ply floor covered with aluminium sheet forms the heel rest for the pilot's feet, the rudder bar being so arranged that the pilot can change the position of his feet slightly so as to use either the instep or toes on the rudder bar. The body is faired off and covered with linen, doped and varnished; it is laced on, so that it can easily be removed for inspection. Although the deck fairing in front of the pilot's cockpit renders it unnecessary to wear goggles, an "Avro" folding windscreen is fitted.
   Rudder bar and rudder controls are of the usual "Avro" type, and the control stick consists of a single steel tube universally mounted at the base. The aileron control wires are taken direct from the control stick, and the elevators are operated through a rocking cross-shaft which is coupled up to the control stick by means of a pull-and-push rod connected to the control stick by universal joints. All control cables are standard stranded cable passing through fairleads. Pulleys are entirely eliminated from the control system, and pulley crank levers are employed where it is necessary to change the direction of the control cables.
   A large instrument board is conveniently placed in front of the pilot's cockpit, and carries the following instruments :- Rev. counter, altimeter, air speed indicator, radiator thermometer, oil pressure gauge, cross level, watch and engine switch. One of the new 35-45 h.p. Green 4-cyl. vertical water-cooled engines is fitted. It drives a 7 ft. 6 in. diameter by 5 ft. 3 in. pitch tractor airscrew at a maximum speed of 1,500 r.p.m. in the air.
   A honeycomb radiator is mounted in the nose of the fuselage.