The Airspeed AS.10 Oxford is a twin-engine monoplane aircraft that was developed and manufactured by Airspeed.
It played a significant role in training British Commonwealth aircrews during the Second World War, specifically in navigation, radio operation, bombing, and gunnery.
The development of the Oxford was initiated by Airspeed in the 1930s in response to a requirement outlined in Specification T.23/36, issued by the British Air Ministry.
The aircraft’s design was primarily based on Airspeed’s earlier AS.6 Envoy, which was originally a commercial passenger aircraft.
Following its successful maiden flight on 19 June 1937, piloted by Percy Colman, the Oxford quickly entered production to support the rapid expansion of the Royal Air Force (RAF) in anticipation of the impending large-scale conflict.
With the outbreak of war, a substantial number of Oxfords were ordered by Britain and its allied nations, including Australia, Canada, France, New Zealand, Poland, and the United States.
Even after the war, the Oxford continued to be in demand internationally, as it was acquired by the newly established air forces of Egypt, India, Israel, and Yugoslavia.
The aircraft was highly regarded as an effective trainer throughout the conflict and was also utilized for various general-purpose roles.
Today, several Oxfords are preserved and displayed worldwide as static exhibits, serving as a testament to their historical significance.
The Oxford was a twin-engine cantilever monoplane with a low-wing design, featuring a semi-monocoque constructed fuselage, a conventional landing gear configuration, and a wooden tail unit.
It was specifically developed to replicate the flight characteristics of various contemporary front-line military aircraft.
The aircraft was designed to fulfill a range of training missions, including navigation, flying instruction, night flying, instrument flying, wireless communication, direction-finding, gunnery, and vertical photography.
The Oxford was meticulously planned and developed to incorporate modern innovations and equipment fittings, including a comprehensive array of instruments and controls within the cockpit, which greatly aided its primary role as a trainer aircraft.
Additionally, the Oxford could also be utilized in secondary roles such as an air ambulance and maritime patrol aircraft.
In terms of flying experience, the Oxford provided a representative and seamless transition for pilots to larger transport aircraft due to its smooth flight characteristics.
The controls were user-friendly, remaining consistent and easily adjustable.
The second pilot’s position was equipped with a fully furnished suite of essential flight instrumentation.
The aircraft was equipped with a standard blind-flying panel, which included an airspeed indicator, altimeter, artificial horizon, directional gyroscope, rate of climb indicator, and turn indicator.
Life support equipment included three oxygen regulators, a flowmeter, three bayonet unions, and three high-pressure oxygen cylinders with a capacity of 750 liters.
The external view from the cockpit was considered superior to most contemporary aircraft of the time, although it was partially obstructed by the engine cowlings, creating blind spots.
The Oxford aircraft was typically operated by a three-person crew, with the seating arrangement being adjustable to accommodate various purposes, such as specialized training roles.
The cockpit was equipped with dual flying controls and two seats, designed to accommodate a pilot and either a navigator or second pilot.
However, when used for bomb aimer training, the second set of controls would be removed to make space for a prone bomb-aimer.
Similarly, when used as a navigation trainer, the second seat would be pushed back to align with the chart table.
Located aft of the cockpit, on the starboard side of the fuselage, was a wireless operator station facing towards the rear.
Additionally, the Oxford I model featured a dorsal turret amidships, which could be utilized for training navigators, bomb-aimers, wireless operators, air gunners, and camera operators.
The center section of the aircraft had the capacity to carry up to 16 11 lb. practice bombs, with bomb-release switches installed at both the pilot and bomb-aimers’ stations for control.
Powering the Oxford were two Armstrong Siddeley Cheetah X air-cooled radial engines, capable of generating 340 hp. Initially, these engines were fitted with wooden fixed-position de Havilland-built propellers, but they were designed to accommodate variable-pitch propellers when they became available.
The starboard engine drove a hydraulic pump and air compressor, which were used for operating the undercarriage, flaps, and braking system.
Additionally, a vacuum pump was present for gyroscopic instrumentations.
The port engine drove a 500-watt electrical generator.
The engine cowling featured an inlet that drew cooling air into a tank, and tinned steel oil tanks were also housed within the cowling.
The nacelles, constructed from welded steel, were attached to the centre section of the wing through four separate rubber-insulated joints.
The Oxford’s retractable undercarriage was designed internally and features twin oleo legs with broken braces that retract into each engine nacelle.
The retraction mechanism is typically actuated by an engine-driven pump, but a manual fallback mechanism is also provided in case of an in-flight engine failure.
The undercarriage wheels are equipped with pneumatically-operated brakes, controlled by a lever on each control column.
Access panels are strategically located beneath the pilot’s cockpit to allow for internal access to the flight controls, hydraulics, and electrical components.
Additionally, inspection panels are present in the outer wing sections.
The Oxford’s semi-monocoque fuselage utilizes spruce longerons and stiffeners beneath a plywood exterior. It is constructed in two sections on separate jigs, with the front and rear sections joined together at the rear bulkhead.
The forward bulkhead is reinforced to ensure the structure can withstand the impact of the aircraft turning over during landing, particularly for inexperienced trainee pilots.
The elevator and fin of the tail unit employ a wooden spar and rib structure covered by fabric.
The fuselage can be partially dismantled, with the wing dividing into three separate sections, allowing for road transportation.
The wing itself is constructed with a stressed-skin ply-covered structure using spruce flanges and ply webs.
The spars are assembled on a single jig, while additional jigs are used for the leading and trailing edge elements.
The outer panels also follow a similar construction method as the center section.
The wings are equipped with hydraulically-operated split flaps, which extend between the ailerons.
Variants
AS.10 Oxford I
The first Mark I flew on 19 June 1937 and entered service with the Central Flying School in November of that year.
By the start of the war, about 300 Mk I Oxfords were in service with the RAF, while a number were also being used by the Royal New Zealand Air Force to train pilots for the RAF.
AS.10 Oxford II
The second planned version was the Oxford II, it didn’t have a turret but had dual controls so it could be used as an advanced pilot trainer as well as training for navigators and radio operators.
At the start of the second World War 70 were in service.
AS.10 Oxford III
Powered by two Cheetah XV engines with 425 hp (315 kW) and Rotol constant speed propellers, used for navigation and radio training.
AS.10 Oxford IV
Flying testbed for de Havilland Gipsy Queen IV engines.
Oxford T.II
Only 9 of these were built, eight of them being conversions of Mk Is.
AS.40 Oxford
Civil conversion for radio research, two built.
AS.41 Oxford
Used by Miles Aircraft as a flying testbed for Alvis Leonides engine, one conversion.
AS.42 Oxford
Oxford I to meet Specification T.39/37 for New Zealand.
AS.43 Oxford
Survey variant of the AS.42
AS.46 Oxford V
The final variant, upgraded to Pratt & Whitney R-985 radial engines with 450 hp (335 kW) and Hamilton-Standard variable-pitch propellers.
Many Mark I and II Oxfords were upgraded to the Mark V standard.
