Spit IIa

[Crumpp]

You can look in the FAR.

http://rgl.faa.gov/Regulatory_and_Gu...4!OpenDocument

The stick rates comes from:

NACA RB No. L4E31

ORIGINALLY ISSUED

May 1944 as Restricted Bulletin L4E31

MAXIMUM RATES OF CONTROL
FROM GROUND TESTS

By De E. Beeler

[IvanK]

NACA did not classify the Spitfire as Unacceptable what it actually said was .."therefore failed to meet the accepted requirements" (NACA's referenced requirements ... nobody else's) and to a specific item. If you read the various NACA reports in their entirety you don't come away with the impression that the Spitfire was a POS from a handling point of view.



They also said with respect to being able to rapidly pull to Clmax without the risk of stalling:



Something most Fighter pilots would consider a highly desirable characteristic.

CRUMPP you said above:

"As for the original premise of this discussion, the effect of a hard buffet for stall warning on turn performance:"

The premise of the discussion was NOT flying in Hard Buffet at all ! but on the very first indication i.e. The "Buzz" or the "Nibble" or the "Burble" ... what ever you want to call it. In a previous post you erroneously said the Buzz and Buffet I described was in fact the stickshaker going off even though in these aeroplanes no stickshaker system was fitted, you also told me that it was only valid technique in FBW aircraft ... even though we were talking about coventional cable/pushrod flight control systems ! You fail to accept that flying on the Buzz was/is a technique practised by Fighter pilots the world over and examples provided in this thread from at my count by 4 independent people/references ... by those that have actually used the technique....including a Spitfire pilot from the Battle Of Britain.

[Crumpp]

The Spitfire was at about 5 lb/g, requirements were around 8 lb/g. So it was too light on the elevator.

It would be unstable if it was <=0 lb/g. It wasn't.

That is not even close to correct. You can easily have a zero static margin for a condition of flight as the NACA determined.

Cable and hinge pressure alone can give you 5lb/G.

[Crumpp]

Do you mean inverted ctrl ?

He is confused.

He does not understand that classifying control characteristics as Neutral does not mean they are at the Neutral Point with a margin of zero as the engineering definition.

The airplane would be unflyable and that is not what the NACA or anyone else who tested and measured the stability and control of the early Spitfires concluded.

The classification is based on the what control inputs by the pilot, that is why it is termed "flying qualities".

For static that is generally the airplanes reaction to a disturbance. If the airplane returns to last trimmed condition of flight with the stick free, it has positive static stability.

If it does not return but just stays on its disturbed course, it is neutral. That is why the NACA classified the aircraft as poor in rough air. It stays on whatever course the disturbance sets it on for practical purposes.

In this case the low positive static margin is stability is probably eaten up by hinge moments or balances leaving the system neutral for all practical purposes. Certainly it would eventually return to course but the time required is longer than the parameters set for positive stability.

If the disturbance increases, it is divergent or negative.

[TomcatViP]

Originally Posted by Crumpp

He is confused.

I was too

Poor post than mine. Will delete/correct content

~S