M.20
|
|
Second prototype of the Miles M.20
|
Role
|
Lightweight fighter
Type of aircraft
|
Manufacturer
|
Miles Aircraft
|
Designer
|
Walter G. Capley
|
First flight
|
15 September 1940
|
Primary user
|
Royal Air Force
(trials only)
|
Number built
|
2 prototypes
|
Developed from
|
Miles Master
|
The
Miles M.20
was a
Second World War
British
fighter
developed by
Miles Aircraft
in 1940. It was designed as a simple and quick-to-build "
emergency fighter
" alternative to the
Royal Air Force
's
Spitfires
and
Hurricanes
should their production become disrupted by bombing expected in the anticipated
German invasion of the United Kingdom
. Due to the subsequent shifting of the German bombing effort after the
Battle of Britain
towards British cities in what became known as
The Blitz
, together with the dispersal of British fighter manufacturing, the
Luftwaffe
's bombing of the original Spitfire and Hurricane factories did not seriously affect production, and so the M.20 proved unnecessary and the design was not pursued.
Design and development
[
edit
]
At the outbreak of the
Second World War
in September 1939, Miles Aircraft began work on a single-engined fighter to supplement the RAF's Spitfires and Hurricanes. A wooden mock-up of the design, the M20/1, was inspected by Sir
Kingsley Wood
, the
Secretary of State for Air
, but no orders followed.
[1]
Following the outbreak of the
Battle of Britain
in July 1940, the Royal Air Force was faced with a potential shortage of fighters. To meet the
Luftwaffe
threat, the
Air Ministry
commissioned Miles to design a simple easy-to-build fighter to
specification
F.19/40. This became the Miles M.20/2. Nine weeks and two days later the first prototype flew.
[2]
[1]
To reduce production time the M.20 employed all-wood construction and used many parts from the earlier
Miles Master
trainer, lacked hydraulics, and had
spatted
fixed
landing gear
. The fixed undercarriage freed space and payload sufficient for twelve .303 Browning machine guns and 5000 rounds, and 154 Imperial gallons (700 litres) of fuel (double the range and ammunition capacity of the
Hawker Hurricane
and
Supermarine Spitfire
).
[3]
The M.20 was fitted with a
bubble canopy
for improved 360-degree vision.
In line with a design philosophy emphasising simplicity, speed and re-using available components, the engine was a
Rolls-Royce Merlin XX
"
power egg
" identical to those used on Merlin-powered
Avro Lancasters
and
Bristol Beaufighters
. This conferred flight performance that fell between those of Britain's two frontline fighters.
Testing and evaluation
[
edit
]
The first prototype first flew on 15 September 1940,
[4]
and was tested at the
A & AEE
under the
military serial number
AX834
against
Specification F.19/40
. Armed with eight
.303 Browning machine guns
like the Hurricane, the M.20 prototype was faster than the Hurricane but slower than Spitfire types then in production, but carried more ammunition and had greater range than either. Once the Luftwaffe had been defeated over Britain, the need for the M.20 vanished and the design was abandoned without entering production. The first prototype was scrapped at
Woodley
.
A second prototype,
U-0228
(later
DR616)
was built to
Specification N.1/41
for a
Fleet Air Arm
shipboard fighter, equipped with an
arrestor hook
and catapult launch points. It first flew on 8 April 1941.
[5]
This variant could be launched by
catapult aircraft merchant ships
which lacked flight decks so the aircraft were to be ditched after their mission, and to facilitate this the undercarriage could be jettisoned. However, obsolete Hurricanes were modified to fill this role, which rendered a shipboard variant of the M.20 unnecessary. Consequently, this prototype was also scrapped.
Test pilot
Eric Brown
flew this aircraft in January 1942. He reported that "although surprisingly nippy in performance, could not match the
Martlet
,
Hurricane
, or
Spitfire
in manoeuvrability".
[6]
It lacked also the excellent deck landing characteristics of the Martlet.
Accounts compare the M.20's performance with that of
Battle of Britain
aircraft. The M.20 (345 mph (555 km/h) at 20,400 ft (6,200 m)) was powered by a
Rolls-Royce Merlin XX
with a two?speed supercharger. A Hurricane IIB with the same engine did 342 mph (550 km/h) at 22,000 ft (6,700 m). A Spitfire Mk.VC, powered by a similar Merlin 45 did 374 mph (602 km/h) at 13,000 ft (4,000 m). The Spitfire was armed with two 20 mm (0.79 in) cannons and four .303 in (7.7 mm) machine guns. The other two aircraft were armed with eight .303 in (7.7 mm) machine guns.
[7]
Specifications (M.20/4)
[
edit
]
Data from
The British Fighter since 1912,
[8]
Miles Aircraft since 1925
[9]
General characteristics
- Crew:
One
- Length:
30 ft 1 in (9.17 m)
- Wingspan:
34 ft 7 in (10.54 m)
- Height:
12 ft 6 in (3.81 m)
- Wing area:
234 sq ft (21.7 m
2
)
- Airfoil
:
root:
NACA 23021
;
tip:
NACA 23009
[10]
- Empty weight:
5,870 lb (2,663 kg)
- Max takeoff weight:
7,758 lb (3,519 kg)
- Fuel capacity:
154 imp gal (185 US gal; 700 L) fuel ; 8.5 imp gal (10 US gal; 39 L)
- Powerplant:
1 ×
Rolls-Royce Merlin XX
V-12 liquid-cooled piston engine, 1,260 hp (940 kW) at 3,000 rpm
- Propellers:
3-bladed
Rotol
constant-speed propeller
Performance
- Maximum speed:
333 mph (536 km/h, 289 kn) at 20,600 ft (6,300 m) combat load
- 350 mph (560 km/h) clean at 20,600 ft (6,300 m)
- Stall speed:
80 mph (130 km/h, 70 kn) flaps down
- 101 mph (163 km/h) flaps up
- Range:
550 mi (890 km, 480 nmi) / 2 hour duration - normal
- 870 mi (756 nmi; 1,400 km) / 5 hours 12 minutes duration - absolute maximum
- Endurance:
5 hours 12 minutes at 9,000 ft (2,743 m)
- Service ceiling:
31,400 ft (9,600 m)
- Absolute ceiling:
35,500 ft (10,800 m)
- Rate of climb:
3,200 ft/min (16 m/s)
- Time to altitude:
20,000 ft (6,100 m) in 9 minutes 36 seconds
- Wing loading:
33.2 lb/sq ft (162 kg/m
2
)
- Take-off run:
810 ft (250 m) with 30° flap
- Take-off distance to 50 ft (15 m):
1,350 ft (410 m) with 30° flap
Armament
See also
[
edit
]
Related development
Aircraft of comparable role, configuration, and era
Related lists
References
[
edit
]
Wikimedia Commons has media related to
Miles M.20
.
Citations
[
edit
]
- ^
a
b
Brown
Aeroplane Monthly
April 1976, pp. 207?208.
- ^
Bridgeman 1946, p. 133.
- ^
Mondey, David (1982).
Hamlyn Concise Guide to British Aircraft of World War II
. Chancellor Press. p. 170.
ISBN
1-85152-668-4
.
- ^
Jarrett 1992, p.55.
- ^
Jarrett 1992, p. 57.
- ^
Wings on my Sleeve, Eric Brown, Pg43
- ^
War Planes of the Second World War, Fighters, Volume 2, William Green, 1961
- ^
Mason 1992, pp. 292?293.
- ^
Brown, Don L. (1970).
Miles Aircraft since 1925
(1st ed.). London: Putnam & Company Ltd. pp.
172
-177.
ISBN
0-370-00127-3
.
- ^
Lednicer, David.
"The Incomplete Guide to Airfoil Usage"
.
m-selig.ae.illinois.edu
. Retrieved
16 April
2019
.
Bibliography
[
edit
]
- Bridgeman, Leonard. "The Miles M.20."
Jane's Fighting Aircraft of World War II
. London: Studio, 1946.
ISBN
1-85170-493-0
.
- Brown, Don. "Last-ditch defender".
Aeroplane Monthly
, Vol. 4, No. 4, April 1976, pp. 207?211.
- Green, William.
Warplanes of the Second World War, Fighters, Vol. 2
. London: Macdonald, 1961.
- Jarrett, Philip. "Nothing Ventured..." Part 21.
Aeroplane Monthly
, Volume 20 No. 1, Issue 225, January 1992, pp. 54?60. London: IPC. ISSN 0143-7240.
- Mason, Francis K.
The British Fighter since 1912
. Annapolis, Maryland: Naval Institute Press, 1992.
ISBN
1-55750-082-7
.
- Mondey, David.
The Hamlyn Concise Guide to British Aircraft of World War II
. London: Chancellor Press, 2002.
ISBN
1-85152-668-4
.
- Swanborough, Gordon.
British Aircraft at War, 1939?1945
. East Sussex, UK: HPC Publishing, 1997.
ISBN
0-9531421-0-8
.