In real life, yes.
ack-ack
In real life, the P-38 was restricted to 20 mph above placarded limits (460 mph TAS), or 480 mph TAS from 20,000 feet and below. This was due to buffeting and nose heaviness, even with the Recovery flaps deployed. The Recovery flaps would initiate a nose-up tendency that would force the pilot to push the yoke forward to maintain the dive. Hands off, the Lightning would pull out unassisted.
I must retract my statement that the Recovery flaps do not work... They work, within the realm of where the P-38's manual states they should work.
Flying level at 20k, I rolled into a steep dive with the Recovery flaps deployed. I was trimmed neutral. Buffeting began at 460 mph TAS. I still had good elevator control at 500 mph. Climbing up to 20k again, I dived once more. As the aircraft began buffeting, I released the stick and it pulled out by itself, the g meter indicating nearly 4g. Speed reached a peak of 499 mph.
I climbed to 25k and repeated the dive. This time, speed peaked at 511 mph and the aircraft was sluggish in responding to the recovery flaps, but I did have enough elevator authority to ease out of the dive. Note that 511 mph TAS was the maximum I was able to attain during the dive.
Using the P-38J, I repeated the 25k dive test and was not able to exceed 511 mph TAS again. However, a lot of trim was required to pull out of the dive.
Thus, I conclude that the Dive Recovery flaps do what they are supposed to do IF you keep your air speed below 500 mph TAS. Also, they do absolutely nothing if you don't trim manually. The auto-trim will counteract the pitch-up tendency with down elevator.
Finally, the Dive Recovery flaps will not help you if you wait too long to deploy them. Deploy them as soon as you begin the dive. A 4g pull-out requires about 5k to avoid hitting the ground. Moreover, if you are already at max speed (about 511 mph) when you deploy them, you will not pull out below 5k without reducing power and using some elevator trim.
My regards,
Widewing
