Stability and Control characteristics of the Early Mark Spitfires

[Glider]

Originally Posted by 6S.Manu

Warning on pilot's notes are not a fabrication.

According the numbers posted by Glider (even if they're from an limited investigation on only 121 accidents... a small sample of course) the 38% of those planes were lost for a overstressed airframe issue.

It is not a limited investigation on only 121 accidents... a small sample of course
Please read the posting again. These were all the accidents from the beginning of 1941 until the end of the war.

There were 121 Spitfire crash investigations between 1941 and May 1945 involving serious structural failure:
22 aileron instability #
46 pilot overstressed airframe
20 pilot error in cloud
13 misuse of oxygen system- pilot error #
3 pilot blacked out #
17 engine failure/fire #

Those marked # cannot be blamed on the airframe
Which leaves 66 where the airframe was a factor out of 23,000+ built during the war and millions of flights
Of those 66 a number would have been when the aircraft were in training units number unknown. I am confident that you would be hard pushed to find a lower accident rate of any front line fighter of any Air Force

The number of 121 matches the losses in Morgan and Shacklady recognised book on the subject so we have two different sources. Also note that the author worked in the accident branch which is independent form the RAF

If you wish to state that I have incorrect figures you had better support that comment.

Let's do it in a mature way... in this thread there are to many childish reactions and it's clear that all is created by the same few posters who keep fighting in every WW2 message board of the web.

I certainly agree that it should be a mature debate, with evidence to support any statement. So I await with some interest your explanation of how you determined that this was a small sample.

[Glider]

People keep mentioning the problems the SPitfire had with the wings bending and having to be replaced as proof of the weakness of the Spitfires wings. As I have said before this did happen but it happened in the last 12 months of the war when the Spit was being used as a dive bomber with 1,000lb payload. Details are in the C SHores books on the 2TAF.
This was fixed with some changes in tactics and the clipping of the wings.

I attach a paper that supports this view. If anyone believes that this was a common situation earlier in the war I invite them to provide similar evidence.

Please note that this happens with a full bomb load (1,000 lb) and the extra rear internal fuel tank. Obviously neither of these were around until late 1944

[6S.Manu]

Originally Posted by Glider

It is not a limited investigation on only 121 accidents... a small sample of course
Please read the posting again. These were all the accidents from the beginning of 1941 until the end of the war.

I certainly agree that it should be a mature debate, with evidence to support any statement. So I await with some interest your explanation of how you determined that this was a small sample.

The interview start with:
"Out of a total of 121 serious or major accidents to Spifires reported to us between the begining of 1941 and the end of the war, 68 involved structural failure in the air. Initially the most common reason for such failures, with 22 instances in 1941 and 1942, was aileron instability. The symptoms were not at all clear cut: the aircraft were usually diving at high speed when they simply fell to pieces."

And finishes with:
"a total of more than 22,000 were built, and we were called in on only 130 occasions"

Maybe I'm reading wrong, you know, but it does not state they were all the Spitfire's accidents during all the war... they are the ones reported to the Air Accident Investigation Branch.

Does this imply these were all the accidents regarding this kind of plane?
Could be that sometimes an investigation was not necessary?
What about accidents over the Channel and France, where they couldn't analyse the wrecks?

[Glider]

Originally Posted by 6S.Manu

The interview start with:
"Out of a total of 121 serious or major accidents to Spifires reported to us between the begining of 1941 and the end of the war, 68 involved structural failure in the air. Initially the most common reason for such failures, with 22 instances in 1941 and 1942, was aileron instability. The symptoms were not at all clear cut: the aircraft were usually diving at high speed when they simply fell to pieces."

If you read the whole piece the next few lines gives the details:-

Only after one of the pilots had survived this traumatic experience and parachuted successfully were we able to find the cause. During his dive he saw both of his ailerons suddenly flip up, producing an extremely violent pitch- up which caused the wing to fail and the aircraft to break up. In collaboration with RAE we did a lot of tests and found that aileron up- float was made possible by stretch in the control cables; in those days tensioning was a hit or miss affair with no compensation for temperature. On our recommendation the RAF introduced a tensometer which ensured accurate tensioning of the controls; this, and the simultaneous introduction of metal surfaced ailerons ('42/'43), cured almost all the cases of aileron instability in the Spitfire

And finishes with:
"a total of more than 22,000 were built, and we were called in on only 130 occasions"

Maybe I'm reading wrong, you know, but it does not state they were all the Spitfire's accidents during all the war... they are the ones reported to the Air Accident Investigation Branch.

You are reading that bit right but you also miss the bit where it says:-

Mr Newton was called in to investigate Spitfire crashes which could not be immediately attributed to pilot error (the same crashes which are detailed in Morgan and Shacklady).

Morgan and Shacklady is a very detailed book that details the history of the Spitfire including an entry for every SPitfire built. The number that the writer gives and the number in the Morgan and Shacklady book give for this type of incident match.

So we have two sources with the same number. Plus the Air Investigation branch are there for a reason. If you are in command of a unit of any type of aircraft and your planes start coming apart you will want to know why, so it isn't unreasonable to to expect losses of this type to be reported.

If you have better sources of information then put them forward, but until that moment I suggest this figure is as good as you are going to get.

I did have a breakdown as to when these incidents happened but cannot find it right now so cannot prove this next statement but the number that happened in training units was around 60-65% but I do put a caviet on that number but it wouldn't be unexpected.

Does this imply these were all the accidents regarding this kind of plane?
Could be that sometimes an investigation was not necessary?

I can only say yes to the best of my knowledge for the reasons stated. As for the second part I cannot say but its unlikely unless someone has repeated a mistake and they know the reason and the numbers do match

[robtek]

Those 130 accidents also don't include those losses, where after a few insignificant machine gun hits, or even only tracers around the cockpit, the pilot overreacted and went in with his ride because of over-g or a spin, which shurely has happened a few times.

It shurely then was accounted under losses because of enemy action.

There were quite a lot Spitfires lost during the BoB and not all had been shot to pieces.

And glider, nobody has said anything about the Spitfire being weak!!!

Only that the Spitfire controls made it relatively easy to reach the structural limits.

[DC338]

The essential problem and the neglected for most of this thread is how do you simulate it?

I think all sides would agree that the Spitfire had sensitive elevator controls. The degree of problem to the pilot is the issue. Yet with a simulator you have other issues that help or hinder the issue.

1.The problem is how do you simulate that in a game where control curves can be altered?

2.How do you simulate it in a game where you don't have the same control type as the real aircraft, with the same type and length of stick.

3.How do you simulate the different trim types. Some had stab trim which suits a return to center type arrangement such as the joysticks we all use. The majority however had trim tabs that change the stick position. how do you accountant for that in the sim? The shifting of the control curve as mentioned above.

4. How do you simulate the tactit feedback that a pilot gets in relation to G and buffet.

5. Who decides how strong the pilot is. This will become the issue when taking about aircraft with "heavy" controls. Heavy to whom.

This thread of 60 odd pages is like a merry go round.

To discuss the issue without addressing how you would simulate and the issues surrounding doing that, is a waste of %%(#ing time and energy.

You are arguing about degrees yet essentially want the same thing, accuracy. "forest for the trees" comes to mind. This is such a small issue in a sim that has much bigger problems, like aircraft not performing to spec.

[robtek]

Originally Posted by DC338

The essential problem and the neglected for most of this thread is how do you simulate it?

I think all sides would agree that the Spitfire had sensitive elevator controls. The degree of problem to the pilot is the issue. Yet with a simulator you have other issues that help or hinder the issue.

1.The problem is how do you simulate that in a game where control curves can be altered?

2.How do you simulate it in a game where you don't have the same control type as the real aircraft, with the same type and length of stick.

3.How do you simulate the different trim types. Some had stab trim which suits a return to center type arrangement such as the joysticks we all use. The majority however had trim tabs that change the stick position. how do you accountant for that in the sim? The shifting of the control curve as mentioned above.

4. How do you simulate the tactit feedback that a pilot gets in relation to G and buffet.

5. Who decides how strong the pilot is. This will become the issue when taking about aircraft with "heavy" controls. Heavy to whom.

This thread of 60 odd pages is like a merry go round.

To discuss the issue without addressing how you would simulate and the issues surrounding doing that, is a waste of %%(#ing time and energy.

You are arguing about degrees yet essentially want the same thing, accuracy. "forest for the trees" comes to mind. This is such a small issue in a sim that has much bigger problems, like aircraft not performing to spec.

For #1, dont make the controls adjustable, the pilot has to adapt to the plane, not the other way around.(only in game adjustments for axes, no native software)

#2, calculate the difference from the different steering columns to a average joystick and use this values for all.

#3, can't be simulated at the moment, same for all, no advantage for anyone.

#4, buffet can be simulated with head shake and g with increasing tunnel vision.

#5, must be 'Joe Average' for all pilots, in a few years maybe a body scan and a computerized fitness test in the setup. (With the body scan some pilots i know couldn't fly 109's anymore )

Just a few ideas, because it is easy to come up with problems, less so with solutions.

[ACE-OF-ACES]

So in summary..

Assuming this is even true..

This is NOT a bug!

It is a limitation of a simulation running on a PC and it associated hardware

Granted, with enough money this could be simulated, and similar things are in million dollar military and commercial simulators

But most of the CoD users can NOT even afford a decent video card, so god knows they are not going to shell out the money for the hardware to simulate this

Long story short, calling this a bug is just not accurate

[NZtyphoon]

Originally Posted by robtek

For #1, dont make the controls adjustable, the pilot has to adapt to the plane, not the other way around.(only in game adjustments for axes, no native software)

#2, calculate the difference from the different steering columns to a average joystick and use this values for all.

#3, can't be simulated at the moment, same for all, no advantage for anyone.

#4, buffet can be simulated with head shake and g with increasing tunnel vision.

#5, must be 'Joe Average' for all pilots, in a few years maybe a body scan and a computerized fitness test in the setup. (With the body scan some pilots i know couldn't fly 109's anymore )

Just a few ideas, because it is easy to come up with problems, less so with solutions.

It will be the developers, not the one posting the bug-tracker, who have to make all of these calculations - assuming that there is a uniformity of equipment, and even player styles throughout the IL2 community - while trying to deal with all of the other bugs flowing into the bug-tracker report. I can just see them lining up pleading to tackle this so-called issue...

[bolox]

I was staying out of this thread but joysticks/control hardware is something i'm very interested in, See http://forum.1cpublishing.eu/showthread.php?t=29958
As much as anyone I want 'as realistic as possible' control behaviour, however I see some problems:-

For #1, dont make the controls adjustable, the pilot has to adapt to the plane, not the other way around.(only in game adjustments for axes, no native software)

Bit of a problem here as not all sticks have the same response.
Expensive sticks can have the ability to change curves outside the game(even on the fly). Therefore 'Joe Bloggs' with a 'cheap' stick is at a potential disadvantage. Personally the reduced range of control of sensitivity in CoD compared to IL2 is already quite good at preventing sticks being used in a totally non historic way.
Spiking pots would be a bigger problem

#2, calculate the difference from the different steering columns to a average joystick and use this values for all.

Umm... so someone who spent ~£1700 for a simcontrol spitfire column won't be able to 'tighten' his response to get the new realistic behaviour- or will l'ong stick' users be accused of cheatibg?

#3 opens up a whole can of worms, so I agree, leave it as is

#4, buffet can be simulated with head shake and g with increasing tunnel vision.

good sound cues here also.

#5 A full medical- nah- there'd be hardly anyone left

because it is easy to come up with problems, less so with solutions.

Very much so, but is also often easier to come up with solutions that are worse than the problem

Also, why in this entire thread has no real mention been made of the other two axes?