Sorry, my mistake, landing gear extended "by G force", but this crew
did survive a "deep stall" :
"
The lowest indicated airspeeds were recorded between 1016:14 and 1016:22. During this period, speeds between 54 KIAS and 110 KIAS were recorded."
(see NTSB accident report:
China Airlines B747SP Loss of Power and Inflight Upset)