Miles Merchantman

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Merchantman
f2
Type: Passenger / cargo plane
Design country:

United KingdomUnited Kingdom United Kingdom

Manufacturer:

Miles Aircraft

First flight:

August 1947

Number of pieces:

1

The Miles Merchantman was a four-engine passenger or cargo aircraft produced by the British manufacturer Miles Aircraft .

development and construction

The Miles M.71 Merchantman was to be the larger successor to the successful Aerovan and was built on a similar production line. Miles wanted to offer a simple and robust high-decker with an easily accessible and configurable cargo and passenger section. As with the Aerovan, this was achieved by mounting the tail unit on a boom, which made it easier to access the tail of the aircraft. In order to be able to carry greater loads, the Merchantman was made larger than its predecessor. The wingspan was increased by a factor of 1.33, the total weight by a factor of 2.2 and the drive power by a factor of 3.2.

Unlike the Aerovan, the airframe of the Merchantman was to be made largely of metal. The only prototype built was, however, equipped with a wooden tail unit in order to shorten the construction time. The wings were covered with fabric behind the rear spar and fitted with the flaps that were typical of Miles and hung under the wings . The ailerons were mounted in the same way. The advantage of this design was that the ailerons could also serve as landing flaps. Furthermore, the ailerons generated less drag than conventional designs. The overall effect was similar to the "second wings" of the Junkers Ju 52 . The additional power for the Merchantman came from the four piston engines of the de Havilland Gipsy Queen type, each with a rated output of 250  hp (184  kW ). These were mounted in long engine nacelles under the wings. The fuel tanks were behind a fire bulkhead .

The Merchantman had a similar boom as the Aerovan, virtually straight to the rudder went where the tapered tail panels with trim tabs were installed. The tail fin was besides the horizontal stabilizer of a centrally mounted part with the rudder and two movable end plates which served as a trim tab. These endplates had the shape typical of Miles aircraft - symmetrical and elliptical at the top and flattened at the bottom. In contrast to the Aerovan, whose central tail unit only had an elliptical shape above the horizontal tail unit, the shape of the Merchantman was also continued under the boom. However, this was changed again shortly after the first flight tests and the lower part of the vertical stabilizer was replaced by a dorsal fin.

Due to the angular fuselage with straight sides, the stern had to compensate for a wide underbody. On the other hand, this created a large interior space that was easily accessible via the rear doors with an integrated ramp. This space had a volume of 780 ft³ (22.1 m³) and the aircraft could carry loads of up to 5,000  lb (2,268  kg ). In the configuration as a passenger aircraft, the interior could accommodate twenty seats in five rows of four. However, there is no record of whether seats have ever been installed in the machine.

The aircraft was equipped with a rigid nose wheel landing gear , the main landing gear of which consisted of short landing gear legs with small double wheels, which were mounted directly under the fuselage. This enabled the loading area to be kept close to the ground. The lower edge of the fuselage was only 2 ft (0.6 m) above the ground. As with the Aerovan, the nose wheel was controllable via the rudder control.

The Merchantman made her maiden flight in mid-August 1947 and was presented with the new tail at the Airshow of the Society of British Aerospace Companies in Radlett the following month . The prototype with the aircraft registration G-AILF remained the only one and was flown until at least November 1947. Miles Aircraft ceased operations in 1947 and was sold to Handley Page . The Merchantman was scrapped in 1948.

Technical specifications

Parameter Data
crew 1
Passengers 20 passengers configured as a passenger aircraft
length 42.75  ft (13.03  m )
span 66.5 ft (20.27 m)
height 14 ft (4.27 m)
Wing area 600  ft² (55.74  m² )
Wing extension 7.4
Max. Takeoff mass 13,000  lb (5,897  kg )
Cruising speed 143  mph (230  km / h )
Top speed 163 mph (262 km / h)
Service ceiling 16,000 ft (4,877 m)
Range 750  NM (1,389  km )
Engines 4 × de Havilland Gipsy Queen 30 with 250  PS (184  kW ) each

See also

literature

  • AJ Jackson: British Civil Aircraft 1919-59 . tape 2 . Putnam Publishing, London 1960 (English).

Individual evidence

  1. ^ A b c A. J. Jackson: British Civil Aircraft 1919-59 . tape 2 . Putnam Publishing, London 1960, pp. 390 (English).
  2. ↑ a b c d e f g h Miles Merchantman . In: Flight International . Reed Business Information, August 28, 1947, p. 221–225 (English, archive.org ).
  3. ^ AJ Jackson: British Civil Aircraft 1919-59 . tape 2 . Putnam Publishing, London 1960, pp. 168-171 (English).
  4. ↑ a b c Gliders and Sailplanes . In: Flight International . Reed Business Information, September 18, 1947, p. 327 (English, archive.org ).
  5. ↑ a b c Miles Merchantman . In: Flight International . Reed Business Information, September 11, 1947, p. 280 (English, archive.org ).
  6. ^ Activity At Woodley . In: Flight International . Reed Business Information, November 20, 1947, p. 587 (English, archive.org ).