Throwing some light on rates of turn

[IvanK]

An excerpt from AVIA 6/2422 "Notes on the turning performance of the Spitfire as affected by Altitude and Flaps"

The only comment I would make is that the full doc discusses the fact that only "Flap 85" (Down) is selectable so the intermediate settings and any values discussed are by estimate/calculation. The values in the table are Sustained turn performance ... without Height loss.

[Kurfürst]

Excellent! Does the report mention the turn time/radii at SL perhaps..?

[IvanK]

Unfortunately no its all 12,000ft and up.

[Kurfürst]

Ahw. :/ I wonder if its possible to convert the figures to different altitudes..?

[Robo.]

Good stuff IvanK, only thing that confuses me is the 'Merlin XX', i guess that's a typo of some sort, or was that some Mk.III testing?

Good information regarding Spitfire flaps down behaviour at page 11 of this document:

http://ntrs.nasa.gov/archive/nasa/ca...1993092582.pdf

[IvanK]

There is a Pencil Note on the first page next to the title "MKIII". This I presume is an annotation to indicate that the document is based on the spitfire MKIII which would also match the XX Merlin. A weird choice of variant to do tests with !

Got the NACA report.

[Crumpp]

An excerpt from AVIA 6/2422 "Notes on the turning performance of the Spitfire as affected by Altitude and Flaps"

You have the entire report?

I am sure it does not say lower 85 degrees of flap and fly around in small circles.

[IvanK]

Yes

[IvanK]

Here are 3 Relevant Fan plots from the report posted without comment

Clean:


Flap 30


Flap 60 and Full at 85.

[Crumpp]

Here are 3 Relevant Fan plots

Do you have the conclusions stated in the report and the conditions?

It appears the RAE contradicts the NACA's findings on the effect of flaps on turn performance as well as what is taught in modern curriculum's.

I really don't think that is the case and I bet that agreement is in the details of the report you posted.

I understand your reluctance to share those details in this report. I would be happy to provide you the NACA findings on this subject.