Caz
RWTS did NOT state that the Aircraft was unairworthy - RWTS's decision not to authorise further trials flying was made against a background of several engine control system malfunctions that had occurred on the ground during start up checks. These had not, at that point, been explained to Boscombe Down's satisfaction by the aircraft or engine Design Authority. The necessary clarification was completed and accepted by Boscombe Down on 24 October 1994. Test flying was resumed without any changes to the aircraft FADEC system, or any additional operating limitations.
Sorry Caz, this is seemingly contradicted by the MoD.
On 7th March 1994 during one of the specified FADEC checks on the ground, the engine (sic) of an HC Mk2 flamed out. Trials at A&AEE were halted while the failure was investigated. The failure was not due to a software fault and flying resumed on 20th April.
However, in the period up to 2nd June 1994 there were a number of incidents involving AIRBORNE HC Mk2 of which approximately 5 (five) were due to FADEC malfunction whilst operating in normal mode. There had also been incidents on the ground.
The postponement of the trials at this time was an expediency within the proper exercise of airworthiness considerations by A&AEE and was not seen as a refusal by individual test pilots to fly the Chinook HC Mk2.
I understand a certain senior officer described A&AEE’s actions as “quite incredible”. Others, more knowledgeable in the application of airworthiness regulations, would call it right and proper.