A newbies impression of the 109 and spit

[Glider]

Originally Posted by Crumpp

Guys,

The Spitfire was a great airplane and a very effective fighter. There was no such thing as a Stability and Control Engineer when the Spitfire was designed.

It was a new science and almost all of the World War II era fighters have some sort of stability and control issue. It is just as important as the aerodynamics in their fighting abilities.

The Bf-109 had issues with the coupling effects of yaw-wise and the lateral axis at high speed.

The FW-190 and P-51 had longitudinal axis stick force reversals at low speeds.

Airplanes simply got faster and heavier so quickly that the engineering science did not keep up. It did matter so much when airplanes were slow and light.

This I totally agree with, problems were not unique to the Spitfire.

[Crumpp]

This I totally agree with, problems were not unique to the Spitfire.

The Spitfire has unique stability and control characteristics.

The most outstanding issue is the Longitudinal Stability and Control of the early marks.

This was corrected in later variants.

The average military pilot might have had basic aerodynamics training but you can bet you ass test pilots had alot more.

Not really Bongo. They were the guys that had the balls to climb into an uproven machine.

Hans Sander related a story of performing a max G pullout from a dive in the early testing of the FW-190. The aircraft was well into the transonic realm of flight and upon recovery exhibited water vapor condensation behind the normal shock.

It turned the wings completely white for a second. He had no idea at the time what happenend and effect scared the pants off him at first. He thought something was wrong with the aircraft. He paused, ensured he had control of the aircraft and all engine indications were in the green. He was prepared to bail out if necessary.

You can see the same effect in this video:

http://www.youtube.com/watch?v=DQDJG...eature=related

[bongodriver]

Nice video, what was it and what are wings? I don't know what this aerodynamite is you speak of.....I'm only a pilot.

[Crumpp]

Nice video, what was it and what are wings? I don't know what this aerodynamite is you speak of.....I'm only a pilot.

In context, the pilots of the 1930's and early 40's had never experienced such a thing.

[Glider]

Originally Posted by Crumpp

The Spitfire has unique stability and control characteristics.

The most outstanding issue is the Longitudinal Stability and Control of the early marks.

This was corrected in later variants.

But everyone said that it was easy to fly, were all the pilots stupid of every nation. Or could it be that the training and the pilots notes did what they should do, warn and enable the pilots to get used to it.

All aircraft have their own unique feature, old and new. To pretend that only the Spitfire had its own problems is foolish pilots notes are not the be all and end all. Most planes have a warning that intentional spins should be avoided but they get spun. The notes are a warning, no more no less

[Kurfürst]

Define easy to fly.

[Crumpp]

Most planes have a warning that intentional spins should be avoided but they get spun.

This is just not true. Spinning an aircraft that is not approved is just plain stupid. The only people that do it are those who do not understand the aerodynamics.

There is a good reason it is not approved to spin. Reason's like it does not recover for example.

Even aerobatic aircraft that must pass spin testing can enter unrecoverable conditions.

"Mayday mayday mayday Pitts 260DB in an unrecoverable flat spin at 3,500 feet."

The airplane crashed in the Everglades, coming to rest partially inverted and nearly vertical in several feet of water. The canopy, which had been jettisoned in flight, was several hundred feet away. The bodies of the pilots were closer by the wreckage; both had bailed out, but there had not been time for their parachutes to open.

Why did this aerobatic aircraft enter an unrecoverable condition in a spin?

Only one aft limit for the CG is specified, but it assumes the maximum acrobatic weight; excessive weight exaggerates the effect of an aft CG position on spin recovery.

The pilot failed to adhere to the Operating Limits as listed in the Pilots Manual. He violated the airworthiness of the design. The aft CG flattened the spin until the dirt barrier stopped it.

http://www.flyingmag.com/safety/acci...overable-spins

Easy to fly doing what? A few circuits of the field, cross country cruise, rolls or loop or two? Sure it was easy to fly.

Easy to fly is very subjective. Longitudinal stability and control measurements and characteristics are not subjective. They are quantifiable characteristics with definitive limits.

[von Brühl]

You're arguing with non-engineers...

[CaptainDoggles]

Originally Posted by von Brühl

You're arguing with non-engineers...

Evidently.

[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.