Gulfstream IV in Bedford MA

[Old Boeing Driver]

Control Lock

The control lock is supposed to lock control surfaces, and prevent advancement of the thrust levers.

I've flown most of the Gulfstream jet models, and they all worked this way.

A Gulfstream maintenance guru friend says that it may be possible that the pin preventing thrust lever advancement was either out of rig, or broken, thereby allowing the control surfaces to be locked, but allowing thrust levers to be advanced (to takeoff power).

However, this was a very experienced crew (in that model), and I would hesitate to say they did not do a flight control check, which is on the checklist.

I'm also curious as to why they were using flaps 10 for takeoff there, and since reverse thrust was selected, why were the buckets closed in all the pictures.