A newbies impression of the 109 and spit

[NZtyphoon]

Originally Posted by Kurfürst

My point is basically the difference how the Spitfire and 109 behaved when getting near the stall. Both gave plenty of warnings, but the difference was as I see it is that once riding the stall, the Spitfire gave very little margin before you actually stalled, and once stalled it went medieval on you.

NACA report Spitfire Va stalling Characteristics with reference to the concluding remarks on page 9...

The airplane possessed some unusual characteristics in stalls that are not required in reference 1. The motion beyond the stall was not violent and an unusual
amount of lateral control was available in many flight conditions, even when full up elevator was applied. The good stalling characteristics allowed the airplane to be
pulled rapidly to maximum lift coefficient in accelerated maneuvers in spite of its neutral static longitudinal stability.

From Spitfire Va Flight Characteristics

Characteristics of the elevator control in accelerated Flight: (pages 8 & 9)

The elevator control was found to be powerful enough to develop either the maximum lift coefficient or the allowable load factor at any speed....(page 8 )

The Spitfire airplane had the unusual quality that allowed it to be flown in a partly stalled condition in accelerated flight without becoming laterally unstable. Violent buffeting occurred, but the control stick could be pulled relatively far back after the initial stall flow breakdown without causing loss of control. With the gun ports open, lateral instability in the form of a right rolll occurred, but not until an up-elevator deflection of 10° had been reached and unmistakeable warning in the form of buffeting had occurred. This subject is discussed more fully in reference 2.

The excellent stall warning made it easy for the pilots to rapidly approach maximum lift coefficient in a turn so long as the speed was low enough to avoid undesirably large accelerations at maximum lift coefficient.
The excellent stall warning possessed by the Spitfire was obtained at the expense of a high maximum lift coefficient. The maximum lift coefficient in accelerated flight was 1.21, while the average lift coefficient throughout a stalled turn was usually about 1.01 (9)

The report goes on to state:

In turns at speeds high enough to prevent reaching maximum lift coefficient because of the excessive accelerations involved, the small static longitudinal stability of the Spitfire caused undue sensitivity of the normal acceleration to small movements of the stick. As shown by the time histories of high-speed turns (figs. 15 to 18 ), it was necessary for the pilot to pull back the stick and then ease it forward almost to its original position in order to enter a turn rapidly without overshooting the desired normal acceleration. Although this procedure appears to come naturally to a skillful pilot, flight records from other airplanes show that a turn may be entered rapidly and the desired normal acceleration may be held constant by a single rearward motion of the stick provided the static stability of an airplane is sufficiently large. By careful flying, the pilot was able to make smooth turns at high speed, as shown by figures 17 and 18. Ordinarily, however, small movements of the stick caused appreciable variations in the normal acceleration, as shown in figures 15 and 20.

This hardly speaks about a deadly stall and it certainly doesn't mean the Spitfire was inherently dangerously unstable as claimed by Crumpp. It would be interesting to know whether this Spitfire, as tested, might have been marginally unstable, because, as noted, the cg position was not accurately known. It would also be interesting to know how the elevator control was affected by the extended mass balances described by Jeffrey Quill.

Getting back to flight qualities in CloD, how would it be possible to replicate these qualities?

[Crumpp]

As this phrase, as it stands here, is to my knowledge right, it does not apply to the spitfire.

Yes and that is why I specifically did not address the Spitfire. In the Spitfire, the benefit of having an elliptical wing efficiency was all but eliminated in compensating for the stall characteristics of an elliptical wing.

[Crumpp]

Stormcrow's comments are borne out by
NACA report Spitfire Va stalling Characteristics

It would help if you understood everything that report says instead of select phrases out of context. If you can't do that , it is practically impossible to hold a discussion.


If you read the report, it states the conditions the aircraft exhibited a very harsh stall. One of those conditions would be in a steep bank with gun ports open. Under those conditions, the aircraft would develop a roll instability and resulting spin.

The conditions matter in aerodynamics.

Yes the Spitfire gave very good stall warning. That large buffet zone comes at a price in diminishing turn performance.

Longitudinal Stability has nothing to do with stall characteristics except to determine how fast the pilot can move the wing through its useable angle of attack range.

The NACA rated the Spitfire as having unacceptable longitudinal stability and control in all conditions of flight. It is either neutral or unstable and this was corrected with bob weights in later marks.

That is not a bias, it is just a fact. None of these aircraft were perfect regarding stability and control. Some were worse than others and it is a fact the early mark Spitfires exhibited a dangerous longitudinal instability. It was an infant science when they were developed.

[NZtyphoon]

Originally Posted by Crumpp

It would help if you understood everything that report says instead of select phrases out of context. If you can't do that , it is practically impossible to hold a discussion.

Some were worse than others and it is a fact the early mark Spitfires exhibited a dangerous longitudinal instability. It was an infant science when they were developed.

Nonsense Crumpp - you are the one who is taking things out of context - note what the report said about the cg calculations cf the A&AEE report on the same aircraft type - the possibility was that the Spitfire flown by NACA was slightly tail heavy.

Not forgetting also what Quill had to say about the early Spitfires - "In general configuration the Mk I and Mk II production aeroplanes were almost identical to the prototype and so there was no problem with their stability. (231-232)" I'll take his word over yours any day.

As for having a "discussion" with you Crumpp - not interested because I know you'll turn it into a loooong, tedious thread, arguing over minute detail, while sticking to your opinion that the Spitfire was "dangerously unstable" no matter what. I don't care what you think because I know you're not interested in any one else's opinion, except when they agree with you.

[Kurfürst]

Originally Posted by NZtyphoon

Nonsense Crumpp - you are the one who is taking things out of context - note what the report said about the cg calculations cf the A&AEE report on the same aircraft type - the possibility was that the Spitfire flown by NACA was slightly tail heavy.

Every report ever written on the Spitfire has apparently flawed because they were always have been made on a 'rogue' plane or a single example that proves nothing etc.

How boring.

Not forgetting also what Quill had to say about the early Spitfires - "In general configuration the Mk I and Mk II production aeroplanes were almost identical to the prototype and so there was no problem with their stability. (231-232)" I'll take his word over yours any day.

Except that everyone knows that Quill is khmm... the most outspoken priest of the Spitfire ever. If you ask Quill, the thing had no faults, and they were also immediately and complete fixed. Over and over again. Which is why he is liked to be quoted so much, as if his word was some kind of ultimate judgement which overwrites detailed reports. Quill may have an opinion, but these reports have the hard facts.

Personally I find Henshaw far, far more objective. At least he doesn't try to make it like how everything was made just perfect, despite some very obscene hiccups in the development (fabric ailerons being one of them)

As for having a "discussion" with you Crumpp - not interested because I know you'll turn it into a loooong, tedious thread, arguing over minute detail, while sticking to your opinion that the Spitfire was "dangerously unstable" no matter what. I don't care what you think because I know you're not interested in any one else's opinion, except when they agree with you.

That's pretty much the very best self-description I have ever read. I mean you keep playing the know-it-better smartass everytime, and then make it like as if the 'a loooong, tedious thread' its someone else fault, and then comes the usual yada-yada about your precious time and how you will put everyone on ignore.

Problem is, you've only registered here to carry over some feuds from other places, and you have made almost as many posts in 2 months as Crumpp or I did in 4 years.

Nope, arguing over minute details is exactly what you like to do. At least don't blame it on others.

[Al Schlageter]

Quill is to the Spitfire as Barbi is to the Bf109.

[Osprey]

Originally Posted by Kurfürst

Except that everyone knows that Quill is khmm... the most outspoken priest of the Spitfire ever. If you ask Quill, the thing had no faults

I find it a bit of a failure in job description that a test pilot would not report any faults because he thought it was perfect. Get real Kurfurst.

[fruitbat]

I just find it pure comedy gold that Kurfursts arrogance and general hatred of the Spit is such that he genuinely believes that he knows more about Spits that Quill did.

says everything you need to know.

[6S.Manu]

The motion beyond the stall was not violent and an unusual
amount of lateral control was available in many flight conditions

The Spitfire airplane had the unusual quality that allowed it to be flown in a partly stalled condition in accelerated flight without becoming laterally unstable

You know that this matter can't be resolved right, do you?

not violent: there is no meter for the stall to be "violent/not violent".
unusual amount: is it possible to quantify the usual one? And usual compared to?
many flight conditions: which ones?
party stlled: again... no numbers.

If we want the real numbers we have to rent a spitfire, install on it all the modern testing stuff and run it.

I've never loved much the 109 while I've always hated the Oleg's Spitfire (but I love the real one since I was a kid): anyway I've never trusted the myth of the elliptical wings because of these planes fly against the physic laws compared to all the other ww2 planes.

[NZtyphoon]

Originally Posted by 6S.Manu

You know that this matter can't be resolved right, do you?

not violent: there is no meter for the stall to be "violent/not violent".
unusual amount: is it possible to quantify the usual one? And usual compared to?
many flight conditions: which ones?
party stlled: again... no numbers.

If we want the real numbers we have to rent a spitfire, install on it all the modern testing stuff and run it.

I've never loved much the 109 while I've always hated the Oleg's Spitfire (but I love the real one since I was a kid): anyway I've never trusted the myth of the elliptical wings because of these planes fly against the physic laws compared to all the other ww2 planes.

The numbers and graphs start on page 25 of the NACA report on the Spitfire Va flight characteristics - which can be downloaded and viewed in its entirety, as can the NACA report on the Spitfire Va stall. Testing a real one would be interesting - Duxford anyone?