Question about the early P-38's

[F4UDOA]

When did the fowler flaps become part of the production airplane?

Did the P-38F have them?

[gripen]

AFAIK the fowler flaps were there right from the beginning. Combat flap setting was introduced during the production of F model.

gripen

edit: grupen transforms to gripen

[Hyflyer81]

The P-38 always had the flaps but! P-38G models had strengthened Fowler flaps which could be used at combat speeds up to 250 m.p.h. to tighten the turning radius. In Europe, pilots of the big Lightnings now found that they could turn inside of the smaller German fighters, particularly at low altitudes. They also had more powerful engines (a 100 hp increase). Production began in August 1942. The "H" model was similar.

[Captain Virgil Hilts]

Originally posted by F4UDOA
When did the fowler flaps become part of the production airplane?

Did the P-38F have them?

The Fowler flaps were present as far back as the XP-38. They were always on the P-38. Somewhere around the late E early F model (I'd have to go look real deep in Bodie's book) a combat setting was introduced to enable a notch of flaps to be deployed at a relatively high speed. There were problems on the XP-38 with the flaps. The linkage was not strong enough, and some "stop gap" measures were taken to fix the problem.

[Widewing]

Originally posted by Captain Virgil Hilts
The Fowler flaps were present as far back as the XP-38. They were always on the P-38. Somewhere around the late E early F model (I'd have to go look real deep in Bodie's book) a combat setting was introduced to enable a notch of flaps to be deployed at a relatively high speed. There were problems on the XP-38 with the flaps. The linkage was not strong enough, and some "stop gap" measures were taken to fix the problem.

The maneuver flap setting was introduced with the P-38F-15-LO.

My regards,

Widewing

[Captain Virgil Hilts]

Thanks. I've been a little busy, and lacked the time to look it up.

[helldiver]

the p-38 didn't originally have "dive flaps" until i think the L model or the J now kits for the field were made but the plane carrying them was shot down by a RAF plane and all 100 kits were lost with the plane carrying them.and the were made to combat compressibilty wich if put into a high alttitide high speed dive the plane would go into the compresibility range wich was the lift decreasing as the plane whent in the area close before supersonic flight and the air turbulance would beat the plane into peices and break the tail and the the rest of the plane would just desintagrate.the sound of a p-38 in the compresibility range made a horrible banshe wail as the chargers sucked air in and the we would hear a soft thump and then we knew what had happened then you would see what was once a p-38 fall from the sky.we lost many good friends like that.but sometimes the plane didin't desintagrate but instead did an outside loop.i had one such experience but i still loved and still do love that p-38 but after that flight i had to get a new flight suit.

[Treize69]

BTW, the flaps used on Late-Model Js and all Ls were not "Dive Flaps".  They did nothing to slow the aircraft, they simply changed the lift profile of the wing to reshape the airflow and prevent shockwave buildup.

And they had to be deployed before the aircraft was in its dive, as deploying them at any high speed (above about 400mph) would cause a sudden pitching up of the nose and a loss of control similar to a high-speed stall.

[helldiver]

that's what i was trying to say.sortof.the reson i called them "dive flaps" is becuse i was not sure what they where actually called.

[Murdr]

"dive recoverly flaps" if you want to be technical about it.

[helldiver]

thanks

[Captain Virgil Hilts]

The first P-38 to be shipped from the factory with dive flaps installed was the P-38J-25-Lo (the P-38J in AHII is probably a P-38J-10-Lo, and does not have them).

They WERE dive flaps, what they were not is dive brakes, as you see on dive bombers.

The dive flaps on a P-38 did not need to slow the plane down. The drag violently increased when the shock wave formed around the center wing at Mach .65.

The dive flaps were SUPPOSED to be deployed BEFORE you entered a dive, but they were often deployed AFTER the dive was started.

The first improvement for the P-38 to solve the dive problems was actually the fillet radius change where the center wing joins the center nacelle.

Something else that had a great effect was the fit around the windows. That area has to be properly fitted and adjusted, or the gaps and distortion will cause severe airflow disruption. That is the reason for the red "No Step" sign under the windows. As little as a 1/16" gap could cause severe problems.

According to several pilots, you could use the dive flaps (they called them "speed boards") in combat to get a momentary "pitch up" of as much as 15 degrees, which you could use to get a quick shot off at times.

The external counterbalance weights on the elevator did absolutely nothing for compressibility. The elevator already had the weight built into it from the beginning, it had a thicker sking and more bracing.

The NACA airfoil profile of the P-38 wing was the cause of the compressibility problems. It accelerated the air faster and earlier than other profiles. It was a tradeoff. That profile allowed a great deal of fuel to be stored in the wing. It also had a very high aspect ratio, which is what makes the P-38 climb and turn well. It helps make up for the relatively high wingload of the P-38.

[helldiver]

true

[bozon]

A silly off-topic question that isn't worth it's own thread:
Did P38s serve in the RAF or RCAF?

Bozon

[straffo]

Almost Bozon , I believe Brits took over French P38 order but well it was not really P38 "Lightning" but more P38 "TeaPot Storm" having their turbocompresseur removed but the 38 specialist here can certainly answer more precisely than I can.

Perhaps did the Brit use the recon version (F5 ...) all I know is St Exupéry lost his life in a  F5B  of the Groupe de Reconnaissance II/33