A newbies impression of the 109 and spit

[von Brühl]

You're arguing with non-engineers...

[CaptainDoggles]

Originally Posted by von Brühl

You're arguing with non-engineers...

Evidently.

[winny]

I thought I'd provide Molders full quote.

"it was very interesting to carry out the flight trials at Rechlin with the Spitfire and Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take off and land. The Hurricane is good natured and turns well, but it's performance is decidedly inferior to that of the Me 109. It has strong stick forces and is 'lazy' on the ailerons.
The Spitfire is one class better. It handles well, is light on the controls, faultless in the turn and has a performance approaching that of the Me 109. As a fighting aircraft it is miserable. A sudden push of the stick will cause the engine to cut, and because the propeller has only 2 pitch settings ( take off and cruise ), in a rapidly changing air combat situation the engine is either over-speeding or else not being used to the full."

It's a pretty fair assessment of the 2 pitch Spit.

And a few lines from the actual trials at Rechlin.

Before turning fights with the Me 109E, it must be noted that in every case, that all three ( Spitfire, Hurricane, Curtiss ) foreign planes have significantly smaller turning circles and turning times. An attack on the opponent as well as a disengagement can only be accomplished on the basis of existing superiority in performance.

What is interesting about the A&AEE trials is that the Spitfire used was using 100 octane and CSP. In May 1940. Which goes some way to explaing the difference between the British and German trials results.

I'm happy to concede that there was an issue with the 109 used. It was the same aircraft that was trailed against the Hurricane in France and if you compare the 2 trials there's a definite decline in the 109's performance between the 2 trials. There was a forced landing made between the 2 dates (about 2 months apart) which probably contributed to this.

I don't think either the Rechlin or A&AEE trails can be considered as 100% accurate. They are what they are! Tests of aircraft on both sides that were not particularly good examples of their types.

[Crumpp]

You're arguing with non-engineers...

It is funny that Morgan and Shacklady quote several pilots who disliked the Spitfire's elevator after the longitudinal instability was fixed by the addition of bob-weights.

They felt it ruined the feel and made the elevator sluggish.

I laughed when I read it.

I bet it did make it feel sluggish if you are used too 3/4 inch stick travel for the available Angle of Attack at 5 lbs per G in neutral or just statically stable!!

[NZtyphoon]

Originally Posted by von Brühl

You're arguing with non-engineers...

Nope, the problem here is that someone who claims to know something about aviation can also make a blanket claim that the Spitfire was an inherently dangerous aircraft, based on two reports which say nothing of the sort.

What they do say is that it did not reach certain NACA standards which had been introduced in 1941 Reference 1. REQUIREMENTS FOR SATISFACTORY FLYING QUALITIES OF AIRPLANES can be found here

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.


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.

Nowhere in any of these reports does it state the Spitfire was dangerous. Strangely enough I actually agree with Kurfurst that it did have a sensitive elevator in certain conditions, but, whatever longitudinal instability it did have was controllable, and most pilots learned to handle it, including wet-behind-the-ears trainees transitioning from the Harvard, which could bite if pushed the wrong way.

All fighters are supposed to have a certain amount of controllable instability, otherwise they would not be able to manoeuvre effectively. Remember the BE2? This was an aircraft which was designed to be stable about all axes and it failed miserably as a fighter, and it was all too easy to shoot down because of that built in stability, although it made a great observation platform which was its original purpose. On the opposite pole there was the Camel which was dangerous to its pilots, although still effective when handled properly.

[CaptainDoggles]

Guys, aircraft stability is not something that's subject to interpretation. Either an aircraft is stable about a particular axis or it is not.

Even NACA agrees that the Spitfire V did not have positive longitudinal stability.

...yet neither of these famous aircraft had the specified levels of the most basic stability of them all, static longitudinal stability...

"Stability" is a quantifiable property, not a subjective classification. An aircraft that is not statically stable can still have good flying qualities. To say that the Spitfire was not statically stable is not to say that all the pilots praising the Spit's handling qualities were wrong.

You guys are getting so caught up in your quest to prove Crumpp wrong that you're losing sight of the facts.

[bongodriver]

Even NACA agrees that the Spitfire V did not have positive longitudinal stability.

Maybe so but this isn't any indication of the 'dangerous instability' crumpp is pushing.
all it means is the spitfire was agile....a desireable quality in a fighter non?

[CaptainDoggles]

Originally Posted by bongodriver

Maybe so but this isn't any indication of the 'dangerous instability' crumpp is pushing.
all it means is the spitfire was agile....a desireable quality in a fighter non?

No, not "maybe so".

The Spit V had zero stability, this is fact.

[bongodriver]

Originally Posted by CaptainDoggles

No, not "maybe so".

The Spit V had zero stability, this is fact.

So how were mere humans able to fly them? total instability is the realms of 5th generation fighter jets that need computers to fly them.

Sorry but you guys are blowing it out your asses if you claim the spitfire had 'no' stability.

[JtD]

Neutral static longitudinal stability doesn't mean no stability at all.