A newbies impression of the 109 and spit

[bongodriver]

the airframe will get stressed enough when it lawn darts.....

[Kurfürst]

Originally Posted by Glider

To summarise:
There were 121 Spitfire crash investigations between 1941 and May 1945 involving serious structural failure:
22 aileron instability
46 pilot overstressed airframe

Aileron instability as well. Interesting.

[Igo kyu]

Originally Posted by robtek

The first that comes to mind is that the stick forces in the 109 were too high to pull out of a high speed dive without using trim.

Too high or even high stick forces make a involuntary overstressing really tough work.

Not disputed by me (someone else may know different). My point was that the Bf 109 was one type of aircraft, which may have been unusual, would you care to name, say, five others that were also unable to be overcontrolled?

[fruitbat]

just out of curiosity, is there a NACA test on the 109E?

[robtek]

Originally Posted by Igo kyu

Not disputed by me (someone else may know different). My point was that the Bf 109 was one type of aircraft, which may have been unusual, would you care to name, say, five others that were also unable to be overcontrolled?

Sorry, there is only one other where i know it for shure, the Me323 "Gigant" where sometimes in rough conditions one pilot alone didn't have enough power to steer it at all.

But "unable " to be overcontrolled stretches the point a bit far, i think.

Every plane with "normal" stick forces and travel was less likely to be overcontrolled with the probability therefore reciprocal related to the stick forces.

[Glider]

Originally Posted by Crumpp

Yes and just as the Operating Notes warn, it is the recovery that is dangerous to the airframe.

Nowhere does it say that recovery is dangerous to the airframe unless you exceed 10G. However if you exceed 10G in any aircraft then or now your chances of making it back in one piece is very limited. I have seen an F4 which pulled 12G and made it back, but it never flew again. We used it for training purposes.

Understand?

Yep, do you?

46 pilots died from it.

You need to read the postings before making comments. Just to remind you what it says:-
The next most serious cause of structural failure in the Spitfire was pilots overstressing the airframe. She was extremely responsive on the controls and one must remember that in those days there was no accelerometer to tell the pilot how close he was to the limit. So it was not difficult to exceed the aircraft's 10G ultimate stress factor (what was the 109's?-) during combat or when pulling out from a high speed dive; during the war we were able to put down 46 major accidents to this cause, though undoubtedly there were many other occasions when it happened and we did not see the wreckage
Where does it say in a spin?
With your experience in spinning can you tell me how you can pull 10g in a spin, in an aircraft the Pilots Notes say is easy to recover from as long as you have height and make a safe speed?

Loss of control is not very well defined, Glider. A spin accident though IS a loss of control accident.

A spin accident is a type of loss of control, all loss of control accidents are not Spin accidents.

Statistically, a very high percentage of those loss of control accidents is a spin.

I urge you to read these papers before you post comments, It summerises that of the fatal accidents 41% ended in a stall/spin but the split between these isn't given and I am sure you agree that there is a world of difference between the two. Its also worth remembering that the key word is ended in a spin, the reason for the accident could be something else.

Another factor is that these are mainly pilots who haven't been trained in spinning. Instruction in spinning isn't part of the requirements for a PPL in the UK and I believe its the same in the USA. Fighter pilots would have been trained in spinning

Spinning is a requirement in the UK for Glider Pilots and you have to pass a number of spinning scenarios before you are allowed to even solo. The final one is to enter a full spin at 1,000 ft and recover before you lose 300ft. As an ex instructor I promise you this isn't easy for some people to learn.

[NZtyphoon]

Originally Posted by fruitbat

just out of curiosity, is there a NACA test on the 109E?

As far as I know a 109E was tested by NACA but the report doesn't seem to be available in their archives http://ntrs.nasa.gov/search.jsp - some further digging may be required.

[Glider]

Originally Posted by Crumpp

Not really bongodriver.

You would have a very hard time overstressing the Bf-109 for example. Especially if you followed the later instructions and did not trim the aircraft during the dive.

It was designed that way through good stability and control engineering.

Ouch, we could have an interesting debate on that but lets keep it to one topic at a time

[Kurfürst]

Does anybody have further details of this Spitfire aileron instability problem the aircraft seem to have been suffering from?

[Crumpp]

With your experience in spinning can you tell me how you can pull 10g in a spin,

You can pull 10G on the z axis anytime you are over 218mph IAS in a Spitfire.

You need to be "well over" 150mph and at 150 mph you are only 68 mph away from the ability to destroy the airframe on a single axis load. That is not very far away.

Problem with spin recovery is you are not on a single axis load as it requires rudder input to recover.

I can see why so many airframes broke up on recovery.