# Auster AOP.6

The Auster AOP.6 was a British military air observation aircraft produced by Auster Aircraft Limited to replace the numerous wartime Taylorcraft Auster aircraft then in-service.

## History

The Auster AOP.6 (Auster Model K) was designed as a successor to the Taylorcraft Auster V, it had a strengthened fuselage, increased all-up weight and a 145 hp (108 kW) de Havilland Gipsy Major 7 engine. It had a different appearance to the wartime Austers due to the lengthened landing gear struts (due to the larger propeller), and external non-retractable aerofoil flaps.
An initial production run of 296 were completed for the Royal Air Force in 1949. A second batch was produced from 1952 with a total delivered of around 400. Some aircraft ordered by the Royal Air Force aircraft were diverted to the Belgian Air Force (22) and the Royal Hong Kong Auxiliary Air Force (2). New aircraft were delivered to Royal Canadian Air Force, South African Air Force, and the Arab Legion Air Force (Jordan).
A dual-control training version of the AOP.6 was produced, 77 serving as the Auster T.7 (Auster Model Q). These flew alongside the AOP.6 in the AOP squadrons.
In 1955 two T.7 aircraft were modified for use on the 1956 Commonwealth Trans-Antarctic Expedition, being designated Auster Antarctic (Auster Model C4). The aircraft had extra radio equipment, larger tail surfaces, the ability to be fitted with floats or skis as required and a bright yellow finish to increase visibility against the snow and ice.
The aircraft was gradually replaced with the Auster AOP.9 from 1955 and surplus aircraft were converted to civilian use, first as the Auster 6A and later as the Beagle A.61 Terrier.

## Variants
### Production
#### Model K - Auster AOP.6

    Production aircraft, 378 built

#### Model Q - Auster T.7

    Dual-control training variant of the AOP.6, 84 built.

#### Auster AOP.8

    Proposed three-seat AOP variant of the T.7, not built.

### Conversions
#### Auster T.7 Antarctic

    Two T.7s converted for use in the 1956 Commonwealth Trans-Antarctic Expedition.

#### Auster T.10

    AOP.6s converted to T7 standard, 10 conversions.

#### Auster 6A Tugmaster

    Former military aircraft converted for use as a civil glider tug.

#### Beagle A.61 Terrier

    Former military aircraft converted for civil use.

#### Marshalls MA.4

    An Auster T7 modified by Marshalls of Cambridge with a new wing and larger tailplane. Perforations in the wing, ailerons and flaps were connected to a suction pump driven by an auxiliary gas turbine engine in the fuselage. The aircraft was used for research into boundary layer control. The sole example, Serial VF665, lost control and crashed on 8 March 1966 in Suffolk, killing both crew.

## Operators
### Military operators
#### Australia

* Royal Australian Air Force (Two AOP.6 aircraft only).

#### Belgium

* Belgian Army (AOP.6)
* Belgian Air Force (AOP.6)

#### Burma

* Burma Air Force (T.7)

#### Canada

* Royal Canadian Air Force (AOP.6 and T.7)

#### Hong Kong

* Royal Hong Kong Auxiliary Air Force

#### India

* Indian Air Force
* Indian Army

#### Jordan (Transjordania)

* Arab Legion (AOP.6 and T.7)
* Royal Jordanian Air Force

#### New Zealand

* Royal New Zealand Air Force - One Auster T.7c was used by the RNZAF for the 1956 Commonwealth Trans-Antarctic Expedition.
** No. 3 Squadron RNZAF

#### Pakistan

* Pakistan Air Force (AOP.6)
* Pakistan Army (AOP.6)
** Pakistan Army Aviation Corps - Ex-Pakistan Air Force aircraft.

#### South Africa

* South African Air Force (AOP.6)

#### United Kingdom

* British Army
** Army Air Corps
* Royal Air Force (AOP.6 and T.7)
** No. 8 Squadron RAF (July 1950 - February 1952)
** No. 209 (Hong Kong) Squadron RAF (November 1958 - March 1959)
** No. 267 Squadron RAF (February 1954 - November 1958)
** No. 651 Squadron RAF (March 1947 - October 1955 & November 1955 - September 1957)
** No. 652 Squadron RAF (September 1946 - September 1957)
** No. 656 Squadron RAF (July 1950 - April 1956)
** No. 657 Squadron RAF (June 1946 - November 1955)
** No. 659 Squadron RAF (May - August 1947)
** No. 661 Squadron RAF (May 1949 - February 1957)
** No. 662 Squadron RAF (February 1949 - February 1957)
** No. 663 Squadron RAF (July 1949 - February 1957)
** No. 664 Squadron RAF (September 1949 - March 1957)
** No. 666 Squadron RAF (June 1949 - March 1957)
** No. 227 Operational Conversion Unit RAF

## Specifications (AOP.6)

Data from Macdonald Aircraft Handbook
General characteristics
* Crew: 2
* Length: 23 ft 9 in (7.24 m)
* Wingspan: 36 ft 0 in (10.97 m)
* Height: 8 ft 4.5 in (2.553 m)
* Wing area: 184 sq ft (17.1 m$^2$) excluding flaps
* Empty weight: 1,413 lb (641 kg)
* Max takeoff weight: 2,160 lb (980 kg)
* Fuel capacity: 23 imp gal (28 US gal; 105 L)
* Powerplant: 1 × de Havilland Gipsy Major 7 4-cylinder air-cooled inverted in-line piston engine, 145 hp (108 kW)
* Propellers: 2-bladed fixed-pitch propeller
Performance
* Maximum speed: 124 mph (200 km/h, 108 kn) at 1,000 ft (305 m)
* Cruise speed: 108 mph (174 km/h, 94 kn)
* Landing speed: 32 mph (28 kn; 51 km/h) with flaps
* Range: 315 mi (507 km, 274 nmi)
* Service ceiling: 14,000 ft (4,300 m)
* Rate of climb: 810 ft/min (4.1 m/s) at 1,800 lb (816 kg)
* Wing loading: 11.7 lb/sq ft (57 kg/m$^2$)
* Power/mass: 0.0676 hp/lb (0.1111 kW/kg)