Author Topic: P-38 stability  (Read 733 times)

Offline mora

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P-38 stability
« on: February 13, 2005, 08:15:18 AM »
The P-38 is surely a stable plane with 2 engines and counter rotating props. However I believe that it's stability is overmodelled in sub-stall speed flight with high AOA. Here's a film I made, the airspeed during the whole flight was below 50mph with elevator trim in full nose up and the stick fully aft most of the time:

http://www.saunalahti.fi/anttruok/film13.ahf

It would be very nice if HTC could look into this issue.

Offline Raptor

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P-38 stability
« Reply #1 on: February 13, 2005, 03:58:53 PM »
stall limiter on?

Offline mora

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P-38 stability
« Reply #2 on: February 13, 2005, 04:39:43 PM »
No way, you couldn't do that with the stall limiter on as it limits your AOA.

Offline 1K3

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P-38 stability
« Reply #3 on: February 13, 2005, 05:41:22 PM »
P-38 IS (and should be in r/l) stable, but in a big furball, you are a sitting target to smaller, more nimble fighters when you get into lo-speed turns.

(but hey, who's stopping you)

:)

btw, try F6F. this 12,000 pound iron can give a hard fite to 38s in co-alt

Offline Ack-Ack

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P-38 stability
« Reply #4 on: February 13, 2005, 07:54:46 PM »
Go to Zeno's site and watch the "Flight Characteristics of the P-38" and see how stable and gentle it was in a stall.  You have to watch closely since you really can't notice the stall except for a slight nose dip during the flight.



ack-ack
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Offline Widewing

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Re: P-38 stability
« Reply #5 on: February 13, 2005, 11:09:19 PM »
Quote
Originally posted by mora
The P-38 is surely a stable plane with 2 engines and counter rotating props. However I believe that it's stability is overmodelled in sub-stall speed flight with high AOA. Here's a film I made, the airspeed during the whole flight was below 50mph with elevator trim in full nose up and the stick fully aft most of the time:

http://www.saunalahti.fi/anttruok/film13.ahf

It would be very nice if HTC could look into this issue.


I can do the same thing with the Ki-84, only at 35 mph. I posted a film of it too. You can take off from a CV with full flaps, pull up into a climb and the CV pulls out ahead of you. Eventually, you have to push the nose over a tad, but you can repeat this over and over.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline Guppy35

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P-38 stability
« Reply #6 on: February 14, 2005, 01:23:57 AM »
Wait a minute!  Are you guys saying we're not flying real planes here?


$)%*&#)%  wanders away mumbling something about shattered dreams :)

Dan/Slack
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Offline mora

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P-38 stability
« Reply #7 on: February 14, 2005, 02:57:24 AM »
Quote
Originally posted by Ack-Ack
Go to Zeno's site and watch the "Flight Characteristics of the P-38" and see how stable and gentle it was in a stall.  You have to watch closely since you really can't notice the stall except for a slight nose dip during the flight.


What we get is a "slight" nose up after the stall, in which you can even climb at 1000fpm

Offline Kweassa

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P-38 stability
« Reply #8 on: February 14, 2005, 03:45:44 AM »
For both planes,

 is it supposed to be that way?

Offline bunch

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P-38 stability
« Reply #9 on: February 14, 2005, 04:02:38 PM »
can anyone do the takeoff-immelman that is in Bob Hoover's book?

Offline Ack-Ack

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P-38 stability
« Reply #10 on: February 14, 2005, 04:05:52 PM »
Quote
Originally posted by mora
What we get is a "slight" nose up after the stall, in which you can even climb at 1000fpm



I've never experienced a "slight nose up" in a stall flying the P-38 in here.  


ack-ack
"If Jesus came back as an airplane, he would be a P-38." - WW2 P-38 pilot
Elite Top Aces +1 Mexican Official Squadron Song

Offline mora

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P-38 stability
« Reply #11 on: February 14, 2005, 04:35:03 PM »
Quote
Originally posted by Ack-Ack
I've never experienced a "slight nose up" in a stall flying the P-38 in here.  


ack-ack


Check the video I posted. I personally think there's a bug which enables you to fly below the stall speed and even climb in that situation.  I think the nose pitches up a little when you fly below the airspeed where you should be stalling.

The easiest way to notice it is to trim the nose fully up and climb in a steep angle while gradually pulling the stick fully aft while while your airspeed is decaying. When you slow down to stall speed and below, your nose will pitch up and you can stay in this sitution forever. If you are under power you should be able to climb with a ridiculous AOA.
« Last Edit: February 14, 2005, 04:42:26 PM by mora »

Offline Widewing

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P-38 stability
« Reply #12 on: February 14, 2005, 05:33:15 PM »
Quote
Originally posted by bunch
can anyone do the takeoff-immelman that is in Bob Hoover's book?


Yes...It's quite easy in the P-38J or L.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline bunch

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P-38 stability
« Reply #13 on: February 15, 2005, 05:08:03 AM »
Well, that is some evidence that the modeling is correct (or incorrect if you assume that none of the AH flyers ar Hoover quality pilots).  I'd have to look in my copy, but i think i remeber he did it single engine also