P38 nuts opinion asked on il2fbaep p38 fm

[Kweassa]

It's also two engines and two fuselages adding extra weight for the wings to support.

[BUG_EAF322]

well that weight was already counted wasn't it ?
well i definitly don't sound like an expert.



WIDEWING!!!!!! HELP!!!!

[HoHun]

Hi Widewing,

>I have read test pilot flight reports on the P-38 from various testing organizations, and no one encountered the scope of reported problems listed by the Brits. In other words, what terrified the Brits barely fazed the Americans who had far greater experience flying the Lightning. That's to expected.

Well, the British only reproduced Lockheed test results. From the report:

"Before the tests were commenced, Messrs. Lockheed produced the three curves showing the incidence of severe buffetting at 10,000, 20,000 and 30,000 feet respectively, as established by Lockheeds test staff."

So the observed ill behavior was normal for the type and known (and acknowledged) by Lockheed.

In fact, the problem described by the BAC applied not only to the Lightning II, but also to later models, as the three curves produced by Lockheed are repeated in somewhat simplified form as the dive placard for the P-38J and L:

http://home.comcast.net/~markw4/p38dive.pdf

So the BAC results were quite representative for the entire P-38 series and confirmed by Lockheeds own findings and statements about operational limits.

By the way, I would consider the result of the tactical trials against the Fw 190A-3 another confirmation of the P-38's problems with accelerated stalls.

And here's a comparison of the Mach-induced drop of the P-38F's and the P-51B's maximum lift coefficient (according to NACA research):

Mach - IAS - P-38F - P-51B

0.3 - 138 mph - 100% - 100%
0.4 - 184 mph - 88% - 93%
0.5 - 230 mph - 74% - 92%
0.6 - 276 mph - 58% - 94%

Again, this shows a serious drop of achievable G rate below what you'd expect from Bernoulli's equation.

Regards,

Henning (HoHun)

[BUG_EAF322]

german planes sukked compared to p38

[Widewing]

Originally posted by HoHun
Hi Widewing,

>I have read test pilot flight reports on the P-38 from various testing organizations, and no one encountered the scope of reported problems listed by the Brits. In other words, what terrified the Brits barely fazed the Americans who had far greater experience flying the Lightning. That's to be expected.

Well, the British only reproduced Lockheed test results. From the report:

"Before the tests were commenced, Messrs. Lockheed produced the three curves showing the incidence of severe buffetting at 10,000, 20,000 and 30,000 feet respectively, as established by Lockheeds test staff."

So the observed ill behavior was normal for the type and known (and acknowledged) by Lockheed.
 

Hiya Henning,

I'm sorry, I was too vague in my statement. I too have the P-38 flight manual and am familiar with the G restrictions outlined on page 30.

What I was referring to was the general attitude of the British testers. Lockheed received complaints about everything imaginable. They didn't like the cockpit layout (but it's a model of organization compared to the Mosquito's cockpit). They didn't like the fuel selectors or their location (out of direct sight). They hated the canopy, they disliked just about everything to one degree or another. I have seen complaints about the buffeting that indicated that the Brit test pilots were horrified with it. Believe me, many USAAF pilots were also horrified by it as well. But, as they became familiar with it, they realized that it wasn't dangerous in itself as long as they did not allow their speed to get too far to the wrong side of the placcard.

My discussions about the P-38 with Ilfrey, Heiden and Ceuleers established to my satisfaction that an experienced pilot can live with the high-speed shake-n-bake. However, each agreed that attempting a steep dive from high altitude was simply stupid. All of the above also flew the P-51D in combat. All thought the P-51D was markedly superior to the P-38 above 20,000 feet. However, to a man, each would take the P-38 if the fight was below 10,000 feet. Much better acceleration and climb. Deft, torque-free handling. Superior low speed agility and mild-mannered departure. All of these things inspire confidence, and confidence is a substantial thing when it comes to combat in fighters.

When Doolittle turned the escorts loose to hunt down the Luftwaffe, the P-38 finally found its niche. Down at low to medium altitudes, P-38s were extremely deadly. Up high, tied to the bombers they were sitting ducks.

My regards,

Widewing

[Widewing]

Originally posted by Kweassa
It's also two engines and two fuselages adding extra weight for the wings to support.

Nonetheless, the P-38 had the best power loading of any American fighter.

My regards,

Widewing

[Ack-Ack]

Originally posted by cat5
Do you know which P-38F submodel that was? I'm curious whether the combat flaps setting was used - only the final production variant of P-38Fs had them.

To the best of my recollection, the P-38F didn't have any dive breaks.  Hell, it didn't have any combat flaps (Fowler flaps), those didn't come until I think the H model.



ack-ack

[Ack-Ack]

Originally posted by Ecliptik
What about with the extra wing area created by partially or fully extended flaps?

The P38 is certainly not a great turner in AH without the aid of flaps.  Only with at least several notches of flaps can the 38 easily turn inside Luftwaffe and other American ETO aircraft.

In AH, it should only take a notch or two of flaps to out turn any US or LuftWhiner plane.



ack-ack

[HoHun]

Hi Widewing,

>What I was referring to was the general attitude of the British testers. Lockheed received complaints about everything imaginable.

Hehe, I got a good laugh from one of their comments:

"Entry into the cockpit on the ground is difficult but easier than emergency exit in flight."

>They didn't like the cockpit layout (but it's a model of organization compared to the Mosquito's cockpit).

You're right, and I actually got a similar good laugh from Corky Meyer's discussion of the confused British cockpits :-) Eric Brown's comment on the heavy RAF gloves ("guaranteed to turn your fingers into a bunch of bananas") was a good one, too!

Still, I don't think there's any doubt that the BAC tests were accurate on a factual level. For example, they mentioned the same overheating problems that later were encountered in the Pacfic, too. (Clay Tice told me that when they were trying to intercept Dinahs, they had to climb in several steps separated by level runs to let the engine cool down again. They never caught a Dinah, I think.)

Two good bits from the BAC report:

- It took about ten seconds to get manifold pressure up from 30" Hg to maximum due to turbo lag. Full performance take-off procedure was to hold the brakes until maximum power was reached and only then release the brakes.

- The P-38F had no automatic boost control so the pilot had to juggle the engine controls constantly. Any asymmetric power setting would result in yawing and in a one-wing-down trim situation.

>My discussions about the P-38 with Ilfrey, Heiden and Ceuleers established to my satisfaction that an experienced pilot can live with the high-speed shake-n-bake. However, each agreed that attempting a steep dive from high altitude was simply stupid.

Well, it comes down to tactics again. As buffeting is followed by loss of elevator authority, even an experienced pilot couldn't do the same high-speed turn as a P-51 or a Fw 190, but knowing that, he'd try to set up the fight to avoid high-speed turns.

I think this might explain why Kelly Johnson preferred to call the compressiblity flaps "compressiblity" flaps instead of "dive" flaps - the gain in dive speed was unremarkable, but it now strikes me that they must have done wonders for the high-speed turn. The replacement of the G-limit dive placard with a no-G-limit placard probably is a key indicator of the improvement achieved with these flaps!

>All of the above also flew the P-51D in combat. All thought the P-51D was markedly superior to the P-38 above 20,000 feet.

That was a comment that quite puzzled me for a while because the P-38 as a turbo-supercharged aircraft should get better and better the higher up the fight takes place. The answer obviously was compressiblity.

Regards,

Henning (HoHun)

[MiloMorai]

Originally posted by Ack-Ack
To the best of my recollection, the P-38F didn't have any dive breaks.  Hell, it didn't have any combat flaps (Fowler flaps), those didn't come until I think the H model.

The 38 always had Fowler flaps.

[BUG_EAF322]

These don't look like fowler flaps but i litle wonder coz fowler flaps where a lockheed invention.
wich first show up on the 1934 lockheed electra.


or are they fowlers ?
maybe they didn't have a combat setting

[dtango]

Greetings Bug:

Those are fowler flaps.  Fowler flaps extend backwards from the wings which is shown in the pic.  2ndly I have reference to other text stating that the P-38 had fowler flaps.  Hope that's useful!

Tango, XO
412th FS Braunco Mustangs

[Ack-Ack]

Originally posted by MiloMorai
The 38 always had Fowler flaps.

Wrong.

The manueverability flaps (also called Fowler Flaps or Combat Flaps) was first introduced in the P-38G and was a feature of all subsequent models.

LOCKHEED P-38G LIGHTNING

P-38G: A further powerplant change to two 1,325 hp Allison V-1710-51/55 (F10R, F10L) engines, each giving an additional 100 hp for cruising. The first version to use the so-called "maneuvering" flaps, a feature of all subsequent models. The Fowler-type flaps are given a special combat setting which permits a small extension and droop to provide greatly increased lift for very little drag. The result is a very high degree of maneuverability over a wide range of speeds. The capacity of the auxiliary fuel tanks was doubled and, fitted with the two 300 US gallon auxiliary fuel tanks, the P-38G was the first US fighter to be ferried across the Atlantic by way of Labrador, Greenland and Iceland. The first trans-oceanic flight was made in 1943 by more than 100 Lightnings, escorted by Boeing B-17 Fortresses for navigational purposes. Deliveries began in August 1942.

Source


ack-ack

[MiloMorai]

Read your quote again AA.

"The Fowler-type flaps are given a special combat setting which permits a small extension and droop to provide greatly increased lift for very little drag."

I am looking at a pic of YP-38s parked on the ramp at the LAT, Burbank. Guess what? They have Fowler flaps.

As can be seen of this F model, it also has Fowler flaps. I believe 'F' becomes before 'G'.



As can be seen in this pic, the 4th production P-38 had Fowler flaps

.

Serial no. for that first production run were Serials nos. 40-644/761 and 40-763/773.

Serials for the F-5A/P-38G production run were as follows:

41-2157    Lockheed F-5A-2-LO Lightning
42-12667/12686  Lockheed F-5A-1-LO Lightning
42-12687/12766  Lockheed P-38G-1-LO Lightning
42-12767/12786  Lockheed F-5A-3-LO Lightning
42-12787/12798  Lockheed P-38G-3-LO Lightning
42-12799/12866  Lockheed P-38G-5-LO Lightning
42-12870/12966  Lockheed P-38G-10-LO Lightning
42-12967/12986  Lockheed F-5A-10-LO Lightning
42-12987/13066  Lockheed P-38G-10-LO Lightning
42-13067/13126  Lockheed F-5A-10-LO Lightning
42-13127/13266  Lockheed P-38G-10-LO Lightning
42-13267/13326  Lockheed F-5A-10-LO Lightning
42-13327/13557  Lockheed P-38G-10-LO Lightning
43-2185/2358    Lockheed P-38G-13-LO Lightning
43-2359/2558    Lockheed P-38G-15-LO Lightning


Notice the '40' and '42/43'. This means the pic of  40-747 was produced 2 years before there was any 'G' model.

So you know what Fowler flaps are here is a rough drawing.

[Kweassa]

The "fowler flap" is a general term - anything that extends in that manner as described in Milo's pic is considered a "fowler". The Ki-84 also had fowler type flaps - except the Japanese called it in a different name.