Does sound rather like a TCMA (Thrust Control Malfunction Accommodation) activation. For those who may not know, TCMA is intended to shutdown an engine that remains at high power uncommanded, with the throttle at or near idle. It was the result of a regulatory mandate that deemed single failure caused Uncontrolled High Thrust (UHT) on the ground to be catastrophic (and hence not certifiable). Since all turbine engine fuel controls have a single failure that can result in UHT (e.g. the fuel metering valve goes hard over), Boeing developed TCMA. TCMA is only active on the ground (and at least on Boeing installations has very robust air/ground logic). The TCMA logic is resident in the FADEC software.
My understanding of the 787 Trent event was that the pilots did some very strange movement of the thrust levers while exiting reverse thrust that confused the TCMA logic and caused the dual shutdown - presumably that logic has been updated.
With regard to this event, I'd be more interested in why they apparently got dual engine thrust lever position fault...
Last edited by tdracer; 29th Aug 2021 at 18:52.