Tandemrotor
You will be aware that even the House of Lords Committee acknowledged that Boscombe Down's decision not to authorise further Chinook Mk2 flight trials in June 1994 was made against a background of several engine control system malfunctions that had occurred on the ground during start up checks, which at that time had not been explained to their satisfaction. Clarification was accepted by Boscombe Down in October 1994 and test flying resumed without any changes to the FADEC system.
You will also be aware that the Operating Restriction as regards Aircraft Weight was adopted as a precautionary measure to ensure that the Chinook remained within the safe, single engine flight regime.