Originally Posted by
Jhieminga
I haven't been able to read up on the F-35's systems, but doesn't it use some convoluted control laws that have the stick controlling altitude in hover mode or something like that? In that particular mode... what can you actually do with the throttle to influence a situation such as this? Can you shut the engine down quickly if needed? The only relevant Harrier is the VAAC one I guess...
The experimental (rear) cockpit (RC) in XW175 didn't have authority to shut down the engine; flight idle was the min the experimental FCS could do, based on the physical limit of travel of the throttle servo. We had a debate once about how to shut down the engine in the case where the aircraft Captain (Safety Pilot in the front cockpit) couldn't do it. Following earlier debates, we'd added a wire-locked (copper wire) switch in the rear cockpit that told the FCS "Independent Monitor" (IM) hardware/software to ignore all the carefully set-up limits. This was so that if the SP was out of action, whoever was in the RC (not always a pilot and frequently not a Harrier pilot) could have a bash at landing using whatever assortment of software and hardware was set-up for the RC at the time, without the IM suddenly deciding to disengage the FCS at an inconvenient moment. If the SP came round, he could always take control (front cockpit disengage switches didn't use software), but otherwise the heroic RC occupant would land it, get the engine to idle and then worry about how to stop the engine. The view was that this could be a job for the airfield fire service.
Not relevant to this F-35B incident, in which it isn't really possible to say from the video what happened except that something went wrong. It's fun reading all the (wrong) theories though.
