Miles Mercury

Miles Mercury
Mk. VI 1946 at Pendeford Airport in Wolverhampton
Type:	Light aircraft
Design country:	United Kingdom
Manufacturer:	Miles Aircraft
First flight:	July 11, 1941
Number of pieces:	6th

The Miles M.28 Mercury is a light aircraft produced by the British manufacturer Miles Aircraft in the early 1940s. Miles only applied for the surname Mercury after the Second World War. However, since Bristol objected to the engine of the same name ( Bristol Mercury ), the name remained unofficial.

history

As early as 1939, George Miles was working on a new three- to four-seat light aircraft that would replace the Miles Whitney Straight and Miles Monarch . With the outbreak of the Second World War, however, work on this was stopped. A resumption took place in 1940, whereby the direction of development changed towards liaison and training aircraft. From the beginning, the designer Ray Bournon adopted many features from contemporary aircraft, such as a retractable landing gear. The Mercury was the first Miles design for which this then modern equipment was intended.

The prototype was completed in the summer of 1941 and made its maiden flight on July 11th from the Woodley Aerodrome, Miles' factory airfield. The aircraft received the Miles test registration (B-Condition-Serial) U0232 . As a training aircraft, the machine was equipped with two steering wheels and seats next to each other. The drive consisted of a 130 hp de Havilland Gipsy Major I. The second prototype flew in 1942 and used a 140 hp Gipsy Major IIA. This machine, also equipped as a training aircraft, had a double control, but a total of three seats, and was tested in the Empire Central Flying School in early 1943 and rated as excellent. At that time, the Ministry of Aircraft Production (MAP) placed an order for a third M.28, with which the possibility of training two student pilots during a flight should be determined by installing a triple control. The flight instructor sat in the middle at the back on the raised third seat with its own control device. In this Mk.-III variant, the increase in wing thickness towards the center was removed, so that the retracted wheels of the landing gear now partially protruded from the surface. Like the other two machines, this one was provided with the dark green / dark brown standard RAF camouflage on the top and yellow undersides. The drive consisted of a Blackburn Cirrus Major III with 150 hp, which acted on a fixed propeller .

At the end of 1943, after testing at the Empire Central Flying School, the Air Ministry issued requirement T.23 / 43 , which required a training aircraft with seats next to each other for students and flight instructors and a third seat behind for a second student pilot. Miles submitted some suggestions for variants of the M.53 , the M.53A based on the cells of the M.28 and M.38 Messenger . In 1946, however, the Percival Prentice was awarded the contract .

Another M.28 was built with the Mk. IV during the war. This had four seats, used a Gipsy Major IIA (145 hp) with a controllable pitch propeller and had only one set of controls. This variant should serve as the basis for series production as a private aircraft . The name Mercury was chosen for marketing, but it was never officially in use because of Bristol objections. Post-war production was limited to just two machines. Sir Harold Hartley, Chairman of British European Airways , ordered the M.28 Mk. VI (150 HP Cirrus Major III), which was approved as G-AHAA and received its certificate of airworthiness on May 3, 1946. Hartley used the machine as his personal aircraft for a year before handing it over to the Airways Aero Association . The last M.28 left the factory in autumn 1947 as Mk. V.

In Germany only one Miles Mercury was in operation, the serial number 6268 with the aircraft registration D-EHAB . The former G-AHAA was registered in this country from August 1956 until it was transferred to Denmark as OY-ALW in April 1978 .

construction

The Mercury is a cantilevered low- wing aircraft with a double tail and a retractable tail wheel landing gear . The construction is made entirely of wood with plywood planking. The wings have a low aspect ratio and have a NACA 23018 profile. The wing thickness increases from the wing root to the stop of the landing gear legs, so that when viewed from the front, the impression of a slight gull wing is created. Further features are a deeply drawn-down Perspex cockpit canopy, vacuum-controlled landing flaps and an air brake under the fuselage.

Whereabouts

variant	Mark	description	Whereabouts
Mk. I	U-0232	130 hp de Havilland Gipsy Major I, fixed pitch propeller, no rear windows, double wheel steering	Broken down in 1942 and the fuselage with rear unit used for the M.38 Messenger prototype
Mk. II	U-0237, later HM583	Built in 1942, 140 HP de Havilland Gipsy Major IIA, fixed pitch propeller, controls like Mk. I	Used by Miles Aircraft as a liaison aircraft, after conversion to 150 HP Blackburn Cirrus Major III, new registration G-AJVX, transferred to Perth in November 1950 , registration VH-BBK
Mk. III	U-0242, later PW937	Built in 1943 on behalf of the Ministry of Aircraft Production for evaluation as a training aircraft with triple control, 150 HP Blackburn Cirrus Major III, fixed propeller, control via joysticks , square rear windows	Registration number G-AISH reserved but not accessed, scrapped in February 1948
Mk. IV	U-243, later G-AGVX	Built in 1944, 145 hp de Havilland Gipsy Major IIA, variable pitch propeller	used by Miles Aircraft as a liaison aircraft, sold to Switzerland in April 1947 (HB-EED), sold to Australia in January 1953 (VH-AKH, later VH-AKC)
Mk. V	G-AJFE	Built in 1947, 150 hp Blackburn Cirrus Major III, fixed pitch propeller, normal control sticks, square rear windows	Registered in Switzerland in June 1951 (HB-EEF), scrapped after an emergency landing on March 13, 1955.
Mk. VI	G-AHAA	Built in 1946, 150 hp Blackburn Cirrus Major III, fixed pitch propeller, wheel control on joystick, oval rear windows	1946 sold to BEA, 1947 to Airways Aero Association, March 1948 to KE Millard & Co., sold to Germany in September 1956 (D-EHAB), September 1976 to Denmark, flown again in April 1978 after years of restoration (OY-ALW)

Technical specifications

Parameter	Data Mercury Mk. I	Data Mercury Mk. IV
crew	2
Passengers	1 to 2
length	7.32 m
span	9.35 m
height	2.54 m
Wing area	15.05 m²
Wing extension	5.8
Empty mass	636 kg	672 kg
Max. Takeoff mass	1052 kg	1090 kg
Cruising speed	216 km / h	248 km / h
Top speed (at sea level)	243 km / h	256 km / h
Range	660 km	770 km
Engines	1 × de Havilland Gipsy Major I, 130 hp	1 × de Havilland Gipsy Major IIA, 145 HP controllable pitch propeller

See also

• List of aircraft types

literature

• Philip Jarrett: For Business and Pleasure No. 3, Miles M.28 Mercury . In: Airplane Monthly September 1986, pp. 474-477
• Miles M.28 Mercury 6 OY-ALW - Preservation Profile No. 5 . In: Airplane Monthly October 1980, p. 542 f.
• Don L. Brown: Miles Aircraft since 1925 , Putnam & Co., 1970, ISBN 0-370-00127-3 , pp. 194-200

Web links

Commons : Miles Mercury  - collection of images, videos and audio files

Individual evidence

1. ^ Air-Britain: The Complete Civil Aircraft Registers of Denmark since 1920 . Air-Britain (Historians), Tonbridge, Kent, UK, 1987, ISBN 0 85130 138 X , p. 21.
2. ↑ On how the vacuum-controlled landing flaps work ( Memento from February 6, 2016 in the Internet Archive )
3. ↑ Photo of the OY-ALW from 2004