Rolls-Royce Mustang Mk.X - Variants

Variants

Mustang Mk.X conversions:

• AG518: Used for engine installation studies, but due to a lack of guns, armour and wireless equipment, it was deemed by Rolls-Royce to be "below" latest production standards and not converted.
• AM121: This aircraft arrived at the Rolls-Royce Flight Test Establishment at Hucknall on 7 June 1942 and was the first to be delivered but the last to be converted. A broader chord fin was installed but the aircraft was not slated for testing at Hucknall and instead was sent to RAF Duxford before being loaned to the 8th Fighter Command USAAF at Bovington along with AL963.
• AL963: First used for performance and handling trials of the Mustang I before conversion on 2 July 1942; its nose contours had a much "sleeker" appearance due to the intercooler radiator being relocated to the main radiator duct. Other changes included a small fin extension and the "blanking" of cowling louvres. This example was able to reach 422 mph (679 km/h) at 22,400 ft (6,828 m). It was sent to the USAAF Air Technical Section at Bovington for evaluation.
• AL975/G: First used for performance and handling trials of the Mustang I before conversion on 2 July 1942; flying for the first time on 13 October 1942. The aircraft was identifiable by a bulged lower engine cowling and was also fitted with a four-blade Spitfire Mk IX propeller. In testing, it achieved a top speed of 425 mph (684 km/h) at 21,000 ft (6,401 m).
• AM203: The third aircraft was fitted with a four-bladed, 11 ft 4 in wooden propeller and achieved 431 mph (694 km/h) at 21,000 ft (6,401 m).
• AM208: The second conversion had the front radiator flap sealed permanently giving a 6-7 mph (10-11 km/h) boost. The same modification was subsequently made to all test aircraft.