Actually, yes they did, at least once. My father, a fighter pilot with
no little experience and then assigned to ComFAirWest after action at
Coral Sea, Midway, and in the Solomons, was the pilot involved with
testing the JATO equipped F4U-1D, Bu No 56048.
This just another idea tested to speed up launches. Prior to the F4U
test it was also tested using an F4F-3 in l943, but as far as I know
only in land based take offs, not launching from carriers. The JATO
units for those tests was primitive, but did provide enough uumph to
push the Wildcat to a shorter take off run. (Not sure who was the
pilot who did the F4F tests.)
F4U testing occurred aboard USS Altamaha on 1 March 1944. He made two
JATO assisted launches that day. According to him, as far as he could
tell, on a straight deck run, the JATO packs added little to the
process. The concept was investigated a means to increase the number
of planes on escort carriers thru shortening the deck space needed for
launch by increasing take off speed. The thrust developed by an R2800
at full power (compared to the Wildcat's R1830) was not particularly
enhanced by the JATO units during takeoff. The place where the
difference in power had its effect was after the airplane had already
left the ship. It was also discovered that, when mixed with salt
spray, the exhaust from the JATO units covered everything with an ugly
white glop that was hard to remove, especially from the windscreens and
canopies of the aircraft parked on the stern. There was some suspicion
that this glop might also have some corrosive effect on aircraft and
equipment if not removed immediately. Bottom line was that it was an
interesting idea, but not terribly practical; in the end, catapults
already in use seemed a much better idea. JATO units on F4U's, nor
any other USN WWII fighters, were not implemented in the Fleet during
the war.
Regards,
Rich