Author Topic: Spitfire IX/Merlin 61 at high altitude (Read 1787 times)

gripen · « **Reply #45 on:** July 14, 2004, 04:18:00 AM »

Guppy35,
The combat radius values in the AHT appear to be a bit contradictory; for the early P-47D it gives 425 miles with 305 gal. internally and 300 gal. externally (2x150gal.), for the late P-47D it gives 600 miles with 370 gal. internally and 300 gal. externally. Probably later radius is for very slow speed cruise power setting which was unpractical in the ETO but possible in the PTO.

Crumpp,
I don't know which NACA test you are talking about? AFAIK NACA never tested roll rates of the Fw 190. The curve for the Fw 190 in the NACA 868 comes from the RAE tests as well as curves for the Spitfires, Typhoon and Mustang (XP-51), P-51B data comes from NACA's own test. The RAE report claims that the tested Fw 190 had heavier ailerons than other two they had that time.

The Mustang had several different aileron combinations during war years. Early Mustang I (same as XP-51) had geared tabs and quite small trow in ailerons which resulted light ailerons througout speed rang, later models had internal balance with or without sealing and larger throw (throw could be changed in the field). In addition NACA and RAE tested several experimental combinations.

gripen

Crumpp · « **Reply #46 on:** July 14, 2004, 07:43:29 AM »

Thanks Gripen.

Have you seen the RAE report? In just thumbing thru the NCAC 868 report it seems they used a combination of actual flight test and wind tunnel evaluations on actual wings.

They do not list WHICH A/C are based on flight test and WHICH are from wind tunnel extrapolation.

They do say that the wind tunnel test's do acount for a wide range of variables which will effect performance and can only give a general estimate.

Crumpp

Crumpp · « **Reply #47 on:** July 14, 2004, 08:30:00 AM »

Quote

They do say that the wind tunnel test's do acount for a wide range of variables

Change that to "DO NOT ACCOUNT for a wide range of variables"

Crumpp

gripen · « **Reply #48 on:** July 14, 2004, 08:41:24 AM »

Crumpp,
I have copy of the report (RAE TN No. 1231), it's available from the PRO as DSIR 23/12865 or AVIA 6/10353.

I have seen most of the original reports they used to create that chart in the NACA 868 (Zero, P-63, F4F, P-40F, P-47 and F6F). Basicly all are real test light data sets (some curves might be extrapolated from 30lbs values and Zero data set does not contain exact control force measurements).

gripen

Crumpp · « **Reply #49 on:** July 14, 2004, 08:51:02 AM »

Then that would explain the discrepancy in the Tactical Trials of the P51B and the FW-190 conducted in England and the NACA 868.

NACA 868 probably accurately reflects the curve of a 190's roll rate it does not accurately reflect the speed of the roll.

Do you know the name of that report so I can check it out?

Thanks

Crumpp

Crumpp · « **Reply #50 on:** July 14, 2004, 09:53:43 AM »

Nevermind Gripen,

You already named the report. This is what happens when you post after running 5 miles!

LOL

Thanks

~~Crumpp~~

Crumpp · « **Reply #51 on:** July 14, 2004, 07:39:13 PM »

Gripen I have used every combination of the report numbers you gave me to search the National Archives. It is not showing up. Can you give me some more Information on that report.

Thanks

Crumpp

gripen · « **Reply #52 on:** July 15, 2004, 12:11:51 AM »

Crumpp,
Just follow the link then choose "Search our cllections" and "> our catalogue (PROCAT)". After that catalogue page opens, now type DSIR 23/12865 to the "go to reference" in upper left corner and click enter. And there you are; "F W 190 aircraft: fighter aileron comparison".

gripen

Crumpp · « **Reply #53 on:** July 15, 2004, 07:17:07 AM »

Got it.

The PROCAT was key.

Thanks for the help.

~~Crumpp~~