US handling reports on the Spitfire

[Trilisser]

Mike's Neil's site has a US handling report on the Tempest V, but anyone with a similar report on the Spitfire?

 

[wells]

There is a NACA report from September 1942. It's probably on the net somewhere.

"Measurements of the Flying Qualities of a Supermarine Spitfire VA Airplane", by William H. Phillips and Joseph R. Vensel
"Stalling Characteristics of the Supermarine Spitfire VA Airplane", same authors

Maybe also check out Jeffrey Quill's book

 

[Vincenzo]

for the first Measurements of the flying qualities of a Supermarine Spitfire VA airplane, Sequence: 3 | UNT Digital Library

 

[Aozora]

Two reports can be downloaded direct from the NACA site:

Handling Qualities of Spitfire Va
Stalling Characteristics of Spitfire VA

 

[finnster]

Thing to remember about these reports: RAE maintained they got the max CL of the spit wrong due to measuring methodology flaws.

 

[Gaston]

Thing to remember about these reports: RAE maintained they got the max CL of the spit wrong due to measuring methodology flaws.

Thing to remember about these reports: RAE maintained they got the max CL of the spit wrong due to measuring methodology flaws.

Low max. lift coefficient seems consistent with fairly moderate sustained turn performance, as is the 3/4 inch travel of the stick to start the stall rumble... Despite popular notion to the opposite, this is very consistent with noticeably inferior sustained turning performance to the Hurricane...

I would like to see what "methodology flaw" evidence was presented by the RAE, as this is the flight behaviour one would expect of a large wing with a low lift coefficient...

The big advantage of the Spitfire in turns was its ability to "stall" with full three-axis control, thus allowing it to "shoot accross the circle" while burning speed with the wings "rumbling"... So, with good pilot knowledge, it still could "win" turn fights (but only with guns blazing!) despite poor actual sustained turn performance, a performance so poor in Soviet eyes it forced them to get away from their usual horizontal turn tactics (they even removed the outer guns to try to lighten it, to no avail)... This Soviet opinion was with the Mk V, which even RAE concede sustained turns equally to the Mk IX at all altitudes (the Mk V was considered superior turning to the Mk IX from many other sources).

Again this is consistent with known Spitfire behaviour, and given the large wings is also consistent with a low lift coefficient per square foot...

Gaston

 

[Aozora]

Low max. lift coefficient seems consistent with fairly moderate sustained turn performance, as is the 3/4 inch travel of the stick to start the stall rumble... Despite popular notion to the opposite, this is very consistent with noticeably inferior sustained turning performance to the Hurricane...

...

 

[finnster]

The RAE contended in Technical note no.aero.1106 dated March 1943
That the NACA testers used a less accurate method. I've attached a jpeg of the document.
Here's something to try - I'm going to have a go later this week- using the same wing area and weight, calculate what the stall speed would be using both the NACA and RAE numbers and see which one matches the documented stall speeds of the Spitfire as shown in the POH.

 

[Ivan1GFP]

CoL of 1.89 sounds awfully high and 1.36 sounds a touch low.
I wonder what the real numbers are for this beast?

- Ivan.

 

[finnster]

I think the 1.36 CL max is the number they got trimmed for best glide engine off. Descending of course, it would generate a low lift. The highnumber would be for the number achieved at MAX AOA and full throttle.
The high number is just a bit higher than I got with a basic calculation of MAX CL and stall using a little program called aircalc.
I'm certainly not an expert, but most of the max CL numbers I see quoted are too low to support the stall speeds given in the POH. so I get puzzled.

 

[JtD]

Do you take the instrument error into account? These usually are not given in the pilot's notes down to stall speed, but a reasonable estimate is possible. I found that you end up in the proper speed/CL range.