Model Forum / General / Models / January 2010

Squadron Signal Walk Around Number 9- F6F Hellcat; states on page 23:

"The flaps on the F6F-3 are hydraulically actuated via the engine driven
hydraulic pump.  By use of a manual selector valve, the flaps can still
be operated after an electrical failure.  They can also be lowered by
use of hydraulic hand pump.  It takes some thirty-five cycles of the
hand pump to extend the flaps, and twenty-five to retract them."

...so - in normal operation they are electrically switched and
hydraulically driven, with a manual hydraulic pressure backup for
emergency operation.