AKAK: P-38 help

[Captain Virgil Hilts]

One of the things I find that is correctly modeled in AH for the P-38 is the fact that the dive flaps WILL give you a momentary nose up pitch of AS MUCH AS 15 degrees. This is correct, as I know several pilots who used this in combat. It does not work, nor is it useful, in ALL situations, but it does in some.

Yes, they are designed and intended to modify the airflow to alleviate the nose down "Mach Tuck" of compression. However, after having guys like Ilfrey, Olds, and a couple of others tell me it worked to give you an extra bit of nose up pitch to get a shot, I tried it and it does work.

I've also used the dive flaps to give me "just a little bit more" when I was low and slow in a turn fight with the flaps all the way down.

Krusty, I suggest you look deeper into how and why the dive flaps really work. I can suggest some books if you like. Or you can email former Lockheed engineer and P-38 expert Warren Bodie and ask him. Your explanation is NOT correct.

[Krusty]

Well that's how they were explained to me, some time ago. I apologize if it's incorrect, and stand corrected.

[Murdr]

Originally posted by VIC
1. Does the 38 performe better with or witout combat trim? (PLEASE ELABORATE ON YOUR ANSWER)

Combat/Manual trim in P38

2. Is it possible to setup a duel throttle to control engines seperately?(I find that decreasing engine RPM on the side that I'm turning to,helps me get around a little faster)

Yes.  I have the 3 finger buttons on my CH throttle set to Select_engine_1, Select_All, Select_engine_2, so that I can work engines independently.  If you had a duel or quadrant throttle that would be better yet.

I am a little suspect of any pronounced turning performance with lessor power to the engine inboard of the turn, but I do find it usefull for boosting roll rate, and departure recoveries.

3.Does the G or J model seem to be more nimble and agile than the L to you?

The G is the tightest turning of the 3.  The J and the L are pretty even though the J has a slight edge in instanious turn rate.  My main ride is the J

4.Is it possible to turn combat trim off completely?(I toggle it off but after I hit auto lvl or auto angle then return to manual control ,the combat trim is on again)

If you have it turned off in preferences/flight, it will work the opposite way, and wont come on after using auto-pilot.  I have a stick button set to toggle CT for making quick adjustments.  Under most conditions I trim elevators to the bottom of the L in "ELE"

Also, in the 479th Raiders Library there are a number of P38 films by AKAK, and myself with some tips in their respective write-ups.

[Murdr]

Actually krusty does have it right in regards to what happens with the airflow.....sort of.  During compression the shockwaves form on top of the wing slightly forward of center, which becomes the dominant air pressure.  Think of it, the high pressure is on TOP of the fore half of the wing.  That's what causes the tuck under effect.  With the dive flaps deployed, and the slight pitch caused by them, the shock wave formation moves aft on the top of the wing.  The compression is still there, but now it is easier to gain lift under the fore of the wing.  They do cause pitch when deployed though.

[The Fugitive]

I find that the most pronouced time you see a difference with combat trim on/off is at very slow speeds like when your roping someone.

With Combat Trim on, at the top of your rope the plane will try to auto trim as you try to flop over....I'm sure AKAK and Murdr and Killn don't "Flop" over at the top as they are much better at this than I and I'm sure much more gracefull .... but as the Combat trim adjusts, and your maneuvering it is very easy to get "stuck" in the air. It can take a number of seconds for the nose to finally fall out and the plane gather some speed to maneuver again.

Without Combat trim on it is very easy to get below 50 knots an still be able to maneuver in the same situation.

For the record, I fly with combat trim off all the time, and flip it on and off quickly to re-trim the plane at different speeds.

[Creton]

thanks for all the advice and will try it out.

all

VIC

[38ruk]

I find that the most pronouced time you see a difference with combat trim on/off is at very slow speeds like when your roping someone.

 
Exactly , it has a major impact on stalls and low speed manuvering . for the most part at anything over 300 MPH auto trim works fine . anything below 250 and its a liabilty . 38