Author Topic: Spitfire NACA reports (Read 7063 times)

Nashwan · « **Reply #90 on:** July 13, 2004, 12:07:20 PM »

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So you believe the test results from NACA are valid Nashwan?

The NACA 868 roll rates for the Spit and 190 are from British tests, and I think are pretty valid, with the proviso that there is natural variation in every plane:

The NACA reports linked at the start of this thread were done by NACA themselves, and Guppy has already posted the condition of that aircraft.

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Your reply is somewhat confusing although the 120/sec would seem right. That would mean 180 degrees in 1.5 seconds or 360 degrees in 3 seconds. Does it list what speed?

No, iirc they said they had no way of checking speeds from the gun cams. I think they checked a lot of films, though, so it probably covers a broad spread of speeds.

Angus · « **Reply #91 on:** July 13, 2004, 12:33:06 PM »

I once looked at guncam films in the IWM London.
A 190 was caught on its 6 by a P51. Down on the deck at full speed it did not try rolling, probably did not have the alt for anything vicious. The 51 shredded the 190.
Poor guy, probably inexperienced while the P51 pilot was a Wing commander.

MiloMorai · « **Reply #92 on:** July 13, 2004, 12:37:46 PM »

Where not those graphs results obtained from calculations?

Crumpp · « **Reply #93 on:** July 13, 2004, 06:40:12 PM »

National Advisory Committee on Aeronautics is a US Government organization that now falls under NASA. So these are not British tests.

http://www.centennialofflight.gov/essay/Evolution_of_Technology/NACA/Tech1.htm

Is this test Wartime data as is indicated on the bottom of the graph based on actual flying or is this calculated from a slide rule?

According to the USAAF/RAF tactical trials conducted in England during the Winter 43/44 the 190 out rolled the P51B under all flight conditions.

According to NACA chart it should not have above 360 mph IAS.

If this is wartime data then it probably IS the FW-190A5/U4 the USAAF tested on 24 Feb 1944 against a Corsiar and a Hellcat in the United States. The Military received that FW-190 from the Bureau of Aeronautics.

Crumpp

Nashwan · « **Reply #94 on:** July 14, 2004, 02:22:31 PM »

868 is a Naca report. That doesn't mean all the data in the report was collected from Naca tests.

In fact, the report says:

"The purpose of the present paper is to summarize rather completely the available information....
No new investigations were attempted in preparing the present paper, although some of the data and analyses had not previously been published"

The British tests were definately tests. They say they used a "rat" to measure angle of bank, a Henschel stick force indicator, and criticise the common way of testing with a stopwatch as inacurate.

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According to the USAAF/RAF tactical trials conducted in England during the Winter 43/44 the 190 out rolled the P51B under all flight conditions.

Have you got the details (speeds, rollrates etc)? All data is helpfull. This wouldn't be the first set of contradictory tests. I know early US tests showed the 190 and F4U to have similar rollrates, which I don't think was borne out by other tests.

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If this is wartime data then it probably IS the FW-190A5/U4 the USAAF tested on 24 Feb 1944 against a Corsiar and a Hellcat in the United States.

It's definately from the British test. The graphs match exactly for the clipped and normal Spits and the Fw190.

Crumpp · « **Reply #95 on:** July 14, 2004, 05:19:57 PM »

I am digging through the National Archives. I have the report number for the test's that the NACA is based on. Thanks.

Crumpp

Charge · « **Reply #96 on:** July 15, 2004, 05:00:53 AM »

"Obviously no one is claiming the 190 should outturn Spitfires or any other plane, which historically it could not."

So you haven't seen the guncam where 190 (alleged) easily turns with and inside P47 and even pulls lead after turning a while with it.

Do you base that claim to wingloading figures?

Ill try to find a link...

-C+

Crumpp · « **Reply #97 on:** July 15, 2004, 07:27:34 AM »

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"Obviously no one is claiming the 190 should outturn Spitfires or any other plane, which historically it could not."

The key phrase is "which historically it could not". Yes the FW-190 could easily outturn a P47 at certain altitudes and speeds. At others the situation was reversed.

If you read the F4U, F4F, and FW190A5/U4 Tactical trials it is pretty evident that something was wrong with the FW they tested. Alieron reversal is not a characteristic of the FW-190 UNLESS the Alierons are improperly set.

Crumpp

Crumpp · « **Reply #98 on:** July 15, 2004, 07:31:48 AM »

Nashwan,

I have ordered the original test the NACA results are based off of from the UK National Archives. According to Gripen the RAF had three FW-190's to choose from to conduct the test. For some odd reason they choose the one which had the stiffest ailerons. This may have been due to other factors that would have rendered the other FW-190's unsuitable for the test.

We will see.

Crumpp

gripen · « **Reply #99 on:** July 15, 2004, 11:02:58 AM »

Crumpp,
There is no "some odd reason" for that particular Fw in the test, it's just typical variation of the frise type ailerons as the report notes.

gripen

Crumpp · « **Reply #100 on:** July 15, 2004, 06:42:53 PM »

I got the report coming.

Thanks

Crumpp

Nashwan · « **Reply #101 on:** July 15, 2004, 08:54:01 PM »

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I have ordered the original test the NACA results are based off of from the UK National Archives. According to Gripen the RAF had three FW-190's to choose from to conduct the test. For some odd reason they choose the one which had the stiffest ailerons. This may have been due to other factors that would have rendered the other FW-190's unsuitable for the test.

It could also be that they didn't have the others at the time the tests were conducted, but did by the time the report was finished.

I have seen some, or possibly even all, the report myself, but I only have brief notes now.

I've often been tempted to order from the pro, but the cost has put me off. AFAIK, you have to pay £10 for a quote on how much the report will cost. If you don't mind me asking, are the reports expensive? I fully understand if you'd rather not say how much.

Crumpp · « **Reply #102 on:** July 15, 2004, 09:03:21 PM »

They are scanning a copy and making a pdf. file. I haven't heard back from them yet but I will let you know.

Crumpp

Crumpp · « **Reply #103 on:** July 21, 2004, 07:19:40 PM »

Heard from the NA today. The cost is 83 pounds and some change. It takes a few weeks for them to get around to doing it but it is coming.

Crumpp

Seeker · « **Reply #104 on:** July 21, 2004, 07:48:34 PM »

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Originally posted by Crumpp
I got the report coming.

Thanks

Crumpp

Thanks; that's a lot of bread for a virtual hobby (83 quid!?!).

Nonetheless ; I've always understood the Spit IX to have the highest WWII mach number.

If I quote a number; I'll only show my ignorance (Badz; +Tiff, help!); but I'm reasonably sure some inbred, buck tooth Imperial chinless Wonder managed to spin the prop off a reasonably standard Spit IX in a presumably controlled dive to record the highest documented mach speed in a WWII fighter aeroplane. (Then again; that's what younger sons are for; don'tcha know? )

Think what he could have achieved if the crate had been not_a_spit and there fore any good?

Perk the 1942 rides!