The engine was test run but did not fly, the project, together with the planned larger variant, the Eagle XX,[1] was cancelled in favour of the Rolls-Royce Kestrel, that was being developed concurrently.
The appearance of the Curtiss D-12, and its importation under license to Britain by Fairey prompted the Air Ministry to ask Rolls-Royce to develop a new aero engine for fighter aircraft, the ministry felt that there were too many engine manufacturers and did not support or encourage the Fairey company to continue.
Normal engine bearers could not be used so the unit was held in the test stand by two conical mounts that attached to the crankcase.
[4] Initial test running was carried out without a supercharger fitted and an improvised carburettor and induction system.
[5] Like the Crecy the Eagle XVI was one of the few Rolls-Royce projects that did not fly, it is of note that the 'X' engine layout was reused in the later Vulture and Exe designs.