The Miles M.25 Martinet was a target tug aircraft of the Royal Air Force (RAF) and Fleet Air Arm (FAA) that was in service during the Second World War. It was the first British aircraft to be designed specifically for target towing.
Work on the Martinet was started in response to the RAF's shortage of obsolete frontline aircraft for target towing duties. A derivative of the Master trainer, it was designed to have as much commonality with existing production aircraft as possible. The first prototype Martinet made its maiden flight on 24 April 1942; quantity production started immediately. A total of 1,724 Martinets were produced, of which the majority were operated either by the RAF or FAA, although some were used by overseas and civilian operators.
The Martinet was also developed into a relatively secret aircraft in response to Specification Q.10/43, which called for a radio-controlled target drone. This aircraft, designated the M.50 Queen Martinet, was only produced in small numbers, and its existence was a state secret until 1946. Several other derivatives of the basic airframe were also produced, including a dedicated glider tug and a trainer variant.
Development
Origins
Before 1941, the target tug role had been met by reusing former frontline aircraft which had either become obsolete or were surplus to requirements. However, while the crucial Battle of Britain was being waged and attrition rates were driven high amongst either side, the RAF found itself with a shortage of frontline aircraft. Seeking to avoid withdrawing existing combat-capable aircraft to perform as target tugs, the Air Ministry opted to procure new build aircraft specifically for this need, approaching Miles Aircraft Ltd with a request to rapidly produce a specialised target tug aircraft based upon the Miles Master trainer aircraft.
The requirements were formalised by the Ministry as Specification 12/41. Amongst the listed requirements was a stipulation that, in order simplify manufacturing as much as possible, the envisioned aircraft ought maximise the use of standardised components wherever feasible.
On 24 April 1942, the first prototype Martinet made its maiden flight from Woodley Aerodrome, flown by chief test pilot Flight Lieutenant Thomas Rose. Results were satisfactory enough for production to begin immediately, leading to the Martinet rapidly supplanting the Master II on Miles' assembly lines at Woodley. In total 1,724 Martinets were produced; the majority of which served with either the RAF or Fleet Air Arm (FAA), although a minority of the type were adopted by overseas operators as well during the post war era.
Further development
The Martinet became the basis for further projects by the company. During 1943, it was decided to produce a derivative of the Martinet that functioned as a radio-controlled target drone to meet Specification Q.10/43. This variant, designated M.50 Queen Martinet, was quickly prototyped and a modest production contact was issued to Miles, leading to 69 examples being manufactured as a new-builds, while a further 17 aircraft were produced via the conversion of production Martinets. During its development and initial years of operation, the existence of the Queen Martinet was classified and the programme was held on the UK Government's Secrets List; it was first publicly displayed at the Farnborough Airshow in June 1946, although details about the type remained protected for a number of years thereafter.
By 1941, officials were considered a proposed improved model of the Master trainer, but such ambitions were sidelined to focus manufacturing resources on the standard Martinet model. By 1945, production pressures had alleviated to the point where serious work could commence, thus Miles set about developing a trainer model of the aircraft, designated M.37 Martinet Trainer. From the onset, this aircraft was intended to be a stopgap measure as the Air Ministry had envisioned its long term trainer to harness turboprop propulsion. The conversion involved the removal of the outboard wing fuel tanks, the installation of a revised cabin with dual controls fitted, and a reduction in overall weight. A pair of prototypes were built, the first of which made its maiden flight on 11 April 1946. However, by the time it was ready for quantity production, more advanced trainers, such as the Avro Athena and Boulton Paul Balliol, had also reached an advanced stage of development, leaving no purpose for the type and thus it received no orders.