Author Topic: P-38L (Read 1022 times)

Widewing · « **Reply #15 on:** August 25, 2003, 05:34:29 PM »

Quote

Originally posted by Eagle327
Too bad they didn't convert the late P38's to swept wings as Grumman did with the F9F Panther-to-Cougar series jets.

Would have solved the 38's dive compression problems.

Cya,
Eagle

Consider that the P-38 used the same NACA airfoil design as the Lockheed Electra transport and you'll better understand why it had problems with localized supersonic airflow. The critical Mach for the P-38 was 0.68 Mach. Compare that to the P-51 with 0.75 and you can see why the P-38 needed the dive recovery flaps.

Sweeping the wings MAY delay the onset of compressibility, but it could not be done simply because the it would drastically change the center of gravity and the center of lift. Just because the Me 262 has wings that are slightly swept, don't think that was done to delay compressibilty, because it wasn't. It was done strictly to keep the center of gravity within required limits. Indeed, the 262 had no more sweep-back than the C-47.

My regards,

Widewing

Ack-Ack · « **Reply #16 on:** August 25, 2003, 06:15:24 PM »

Quote

Originally posted by Bodhi
Ack Ack,

They only solved the problem if the pilot remembered to deploy them BEFORE or just after he initiated a high speed resultant dive. Otherwise the actuator motor would not have sufficient force to deploy the "flap".

And that's the problem I see in here in regards to those that don't fly the P-38L that much in AH. I think that's how the P-38 got its nasty reputation for compressing in the game. The ones that fly the P-38 as their primary ride usually don't have that problem unless we had a brain fart and forgot to engage the dive flaps.

Almost kind of mirrors real life when the P-38 was plagued with problems in the early years when pilots received insufficient training in the P-38 and didn't have a clear, if any, understanding of what compressability was.

ack-ack

Steve · « **Reply #17 on:** August 25, 2003, 06:18:14 PM »

I'm curious on this, what are the guidelines on how/when to employ the dive brakes on a p38 in AH?

Ike 2K# · « **Reply #18 on:** August 25, 2003, 06:52:54 PM »

employ 'em when you hit TAS 400 mph while your on a steep dive and pull stick up...

Widewing · « **Reply #19 on:** August 25, 2003, 07:58:20 PM »

Quote

Originally posted by Ike 2K#
employ 'em when you hit TAS 400 mph while your on a steep dive and pull stick up...

My experience with the P-38L is that if you have the plane properly trimmed, deploying the dive recovery flaps induces pullout without backpressure on the stick.

My regards,

Widewing

Ike 2K# · « **Reply #20 on:** August 25, 2003, 08:41:21 PM »

here's a new question... did P-38L have a different paint scheme besides the one we have right now (rough silver)?

mos · « **Reply #21 on:** August 25, 2003, 11:12:36 PM »

There's the olive-drab color most associated with the Pacific Theatre. I prefer the silver one with invasion stripes, myself.

Rutilant · « **Reply #22 on:** August 26, 2003, 01:32:20 AM »

I wish we didnt have any 'silver' planes in the set.. I wouldnt mind if they were actually silver. But they're white.

Ack-Ack · « **Reply #23 on:** August 26, 2003, 02:32:20 AM »

Quote

Originally posted by Steve
I'm curious on this, what are the guidelines on how/when to employ the dive brakes on a p38 in AH?

Some say the dive flaps don't work on the P-38L but like Widewing said, I've found out that if properly trimmed, the dive flaps will give about a 3-4 degree positive lift.

When I deploy the dive flaps, it's almost always as I start my dive. I rarely engage it during the actual dive itself and if you have combat trim turned on, it will pretty much render the dive flaps useless as it will automatically compensate for the lift generated by the dive flaps.

You can, like Ike#2 said, only deploy the dive flaps at 400mph IAS but it won't hurt anything and it's a good habit to start if you engage them at the beginning of your dive. My dives are usually started below 300mph IAS, usually around 250mph IAS and use my throttle to keep myself on the edge of compressability so that I still have control, although sluggish from riding on the edge of a high speed buffet. If you start your dive below 20,000ft, you don't have to worry about using the dive flaps since you won't compress at lower altitudes. Also, another misconception is that the dive flaps can also be used as dive brakes but I've found out that the drag caused by the dive flaps is insufficient enough to be of much use as a dive brake, unlike the P-38J in AW. If you fly the P-38L long enough, you'll find out some other useful stuff the dive flaps can do.

ack-ack

Ack-Ack · « **Reply #24 on:** August 26, 2003, 02:36:44 AM »

Quote

Originally posted by Rutilant
I wish we didnt have any 'silver' planes in the set.. I wouldnt mind if they were actually silver. But they're white.

I think the metal finish was mandated by the USAAF in '44 but that a lot of the pilots didn't like them because it made them stand out more. But when they found out that lack of paint meant less weight on the P-38, they accepted that minor benefit. Not sure if the guys in the PTO were ordered to do the same thing since they tended to do things quite differently than the ETO USAAF.

Ack-Ack

Kweassa · « **Reply #25 on:** August 26, 2003, 10:24:27 AM »

Not a big thing, but small correction, Akak.

The combat trims work differently. What they do, is change trim settings according to different speeds in a premise that they are flying level, regardless of the condition of the plane. So when combat flaps are engaged during a dive, the CT doesn't necessarily "adjust according to the lift the dive flaps generate".

What it does, is just simply keeps pushing the elevator trim downwards as much as needed if that plane would have been flying level. So, in a dive, once certain speed is achieved, the pilot can let go of the stick and the plane just automatically 'unloads' the plane via CT - that's usually the case when inexperienced P-38L/Bf109 pilots crash to the ground.

For instance, in a low-alt, high speed chase near about 400mph, the pilot could push the stick just a teeney bit forward, expecting to get 20~30mph extra speed. But if CT is on, even if they push only a teensey bit the elevator suddenly locks up and the nose pitch keeps dropping further and further by itself as if the pilot was pushing the stick forward.

You can confirm this by observing the behavior of CT when flaps are deployed for landing putposes. The flaps generate extra lift, and drags the speed of the plane down. The CT keeps pushing the elevator trim upwards since the plane is losing speed, and this combined with the flap lift, the plane noses up and climbs towards the sky, and then it stalls itself out unless the pilot overrides the CT and readjusts it manually according to the status of his plane, or forcibly keeps the pitch down by pushing the stick.

If the CT accounted for the lift status of the plane, that would not be seen.

AtmkRstr · « **Reply #26 on:** August 26, 2003, 05:23:58 PM »

Quote

Originally posted by Ike 2K#
here's a new question... did P-38L have a different paint scheme besides the one we have right now (rough silver)?

Hey, you're hijaking your own thread!

Steve · « **Reply #27 on:** August 26, 2003, 06:12:24 PM »

Thanks for the answers, everyone!

cobia38 · « **Reply #28 on:** August 26, 2003, 11:46:34 PM »

All this 38 talk is given me a woody

mos · « **Reply #29 on:** August 27, 2003, 12:32:12 AM »

I think a lot of people have trouble flying the P38 because they see the 2000 rounds of 50 cals, and think they have to have it. Actually, the opposite is true. The 2000 rounds really makes your nose heavy and you can't fight in the vertical nearly as well. Try it, next time use the 800 round load out. Not only will you be making tighter turns and find it easier to keep your nose up, but you won't be tempted to stick around and fight so much when you should really be running for home.