Stability and Control characteristics of the Early Mark Spitfires

[Crumpp]

4) As you says, I repeat, I can be that some accidents not reported as result of a past investigation. A plane is losing its wings during recovery from a dive? The first accident of this kind required an investigation, probably also the second one... but how many until it's clear that the plane can be pull so much and it become ?

#4 Again, unquantifiable speculation

It is not speculation. It is a fact, the early mark Spitfire had neutral to unstable longitudinal stability at normal and aft CG. It is a fact, the controls were too light and too effective.

This combination is why you see the warnings in the Operating Notes.

It was real and it could kill you if ignored.

[IvanK]

So now we have Beechcraft Bonanzas and Debonairs in this Spitfire thread !!!!!! .... talk about thread drift.

Keeping with the drift though, in your Bonanza V tail structural failure number crunching example you quote 17,000 Bonanza/Debonairs being made but isnt the Debonair a single fin aeroplane ? Did it have the same structural issues as the V tail Bonanzas ? If it did fair enough but if it didn't should it be included ?

Dont really care either way just saying.

[Glider]

Originally Posted by Crumpp

. Cambridge awards degrees, they published the book, and it is used as a reference in many engineering curriculuums.

If you don't like those facts, tell Cambridge not me.

Cambridge don't issue degrees, they do publish books which are used in institutions but they do not teach.

However and most importantly we are still waiting for your evidence to support your statement about piles of bent wings in the BOB.

Without evidence your statement is useless, should be withdrawn and without it your argument goes with it.

You will agree I am sure that it the professional approach

[Glider]

Once again you are putting your own spin onto a paper that it presented to you.

Originally Posted by Crumpp

Good stuff...

He says 25 were lost due to structural failure he uncovered in his research. That is quite a few.

That is only the ones that were lost due to total failure as well as the ones we know about. It does not tell us the number of aircraft which flew home with bent wings or the ones that broke up over enemy territory.

To put that 25 unfortunate Spitfires in perspective:

~2488 Spitfire Mk I and II's were produced

2488/25 = 99.52

Where does he say only Mk 1 and II's? He doesn't so lets apply your logic to all the spits produced in the war
23,000/25 = 920

So for every 100 Spitfires, one was lost to structural failure.

So for every 920 Spitfires one was lost to structural failure

Now let's compare that to the Beechcraft Bonanza which also had some developmental issues with the V-tail that resulted in structural failure. It is the airplane that forged the "Doctor Killer" reputation.

>17000 Beechcraft Debonair/Bonanza's have been built.

Taking structural failures from 2007 on back we find that 148 airframes have been lost. We have much better records of a peacetime GA aircraft.

http://www.thomaspturner.net/infligh...ups%20NTSB.htm

17,000 / 148 = 114.8

So, For every 115 Beechcraft Debonair/Bonanza's built, ONE has experienced structural failure.

So for every 920 Spitfires produced in the war ( I could increase this number to all spits built) One experienced a structural failure.
In other words you are about 8 times safer in a Spit in wartime than in a peacetime Bonanza

I think the early Mark Spitfire would have had the same reputation in peacetime as the Bonanza due to its high rate of structural failure.

I think the early Mark Spitfire would have had a much better reputation in peacetime than the Bonanza due to its much safer record iro structural security

[6S.Manu]

Thks for the answers.

Originally Posted by NZtyphoon

1) The body responsible for investigating air accidents before and during WW2 was the AIB (Accidents Investigation Branch) which was responsible for investigating all air accidents. http://www.aaib.gov.uk/about_us/history.cfm
2) Why bother speculating on a question which can never be answered? It's like asking how long is a piece of string.
3) Presumably whatever was available - if a wreck was at the bottom of the sea AIB would not have gone chasing after it.
4)Again, unquantifiable speculation

Originally Posted by bongodriver

1) in all probability yes....it's their job, why call in people who aren't qualified?
2) probably a very small amount, in all likelyhood just the events which lead to MIA and unknown fates.
3) as long as the methods produced the answer does it matter?
4) let's not forget that most Spitfire pilots were flying with a squadron and the squadron pilots are all credible eye witnesses to what happens, through all of the recounted stories and biographies etc nobody ever mentioned the Spitfire as being 'particularily' weak or seeing squad mates breaking up with any regularity.

1) I looked in the website but I asked because it's not written that's the only responsable of investigation but it's part of the entire Department.

A Department could delegate some accidents to a company and other crashes to another: my doubt is the existence of another qualified company during that time... it's a natural to make use of external help (the AAIB was indipendent) during difficult times. So is it sure that the RAF had not a internal investigation departement and AAIB was the only responsable? Could it be that it was responsable for the accidents in a determined territory (England)?

2) & 3) I ask because of the possibility of not investigated accidents regarding structural failure: if so the Mr.Newton's numbers posted by Glider are far less interesting: as I said, since those were only accidents with a defined wreckage, how many more planes went down for structural failure over the sea (the channel, Malta ect)?
I think an investigation would always require witnesses... my question was if there would be an investigation at all in case of no wreckage.

4) Bongo, I know... infact I expect that the loss of the wings was a rare accident: I think more of a not critically damaged airframe for which, I think to have read somewhere, the plane had to be partially rebuild... could a plane with partial airframe damage have the same performance? Does its manouvrability and stability remain the same? Because IMO in combat area easily a damaged plane would be taken down by the enemy...

I know it's speculation, but not useless IMO. To have the complete picture we need to be sure of these things, otherwise there is no absolute truth.

[NZtyphoon]

Originally Posted by Crumpp

Good stuff...

He says 25 were lost due to structural failure he uncovered in his research. That is quite a few.

That is only the ones that were lost due to total failure as well as the ones we know about. It does not tell us the number of aircraft which flew home with bent wings or the ones that broke up over enemy territory.

To put that 25 unfortunate Spitfires in perspective:

~2488 Spitfire Mk I and II's were produced

2488/25 = 99.52

So for every 100 Spitfires, one was lost to structural failure.

Garbage, he's talking about all Spitfires built



~20,351/25 Spitfires built = 1 in 821

Originally Posted by Crumpp

>17000 Beechcraft Debonair/Bonanza's have been built.

Taking structural failures from 2007 on back we find that 148 airframes have been lost. We have much better records of a peacetime GA aircraft.

http://www.thomaspturner.net/infligh...ups%20NTSB.htm

17,000 / 148 = 114.8

So, For every 115 Beechcraft Debonair/Bonanza's built, ONE has experienced structural failure.

http://www.tsgc.utexas.edu/archive/g...ics/vtail.html

Originally Posted by Crumpp

I think the early Mark Spitfire would have had the same reputation in peacetime as the Bonanza due to its high rate of structural failure.

Nope, the Beechcraft, a high speed interceptor fighter built to withstand combat conditions in wartime, was 7 - 8 times more likely to fall apart.

Originally Posted by Crumpp

He says 25 were lost due to structural failure he uncovered in his research. That is quite a few.

That is only the ones that were lost due to total failure as well as the ones we know about. It does not tell us the number of aircraft which flew home with bent wings or the ones that broke up over enemy territory.

One can speculate on this as much as one likes - unless Crumpp or anyone else can provide documentary evidence to back such statements that's all it is. Besides which Spitfires returning home, even with buckled wings (assuming the stacks of buckled wings seen in MU hangers can be believed), were not destroyed through structural failure and could be repaired and put back into service.

To match Beechcraft Bonanza stats for every Spitfire known to have been destroyed through structural failure another 4.5, or over 100 at least would have to fail over enemy territory - a wonderful propaganda opportunity had it happened. No doubt Crumpp can present lots of documented evidence that this happened.

Originally Posted by IvanK

So now we have Beechcraft Bonanzas and Debonairs in this Spitfire thread !!!!!! .... talk about thread drift.

Keeping with the drift though, in your Bonanza V tail structural failure number crunching example you quote 17,000 Bonanza/Debonairs being made but isnt the Debonair a single fin aeroplane ? Did it have the same structural issues as the V tail Bonanzas ? If it did fair enough but if it didn't should it be included ?

Dont really care either way just saying.

The V-tail has a very high rate of in-flight failures. Compared with the Model 33, which is the same aircraft with a conventional straight-tail, the V-tail has a fatal in-flight failure rate 24 times as high as the Straight tail Bonanza. In spite of this glaring statistic, Beech claimed that there was no problem with the V-tail, and for many years the public seemed to agree with Beech. However, the deaths from in-flight failures continued to mount. The V-tail Bonanza is a classic tale of a dangerous item, which because of its popularity continued to kill.

Can't remember anything like this being written about the Spitfire, even by its harshest critics, including NACA and the Pilot's Notes...

[Crumpp]

Because IMO in combat area easily a damaged plane would be taken down by the enemy...

That is correct. A bent airframe is not good. The plane is hard to control and weakenend.

I ask because of the possibility of not investigated accidents regarding structural failure

There were plenty of uninvestigated accidents. In wartime, they would be chaulked up to the enemy. Common sense tells us that wings coming off in a dogfight would be chaulked up to enemy fire or pilot suddenly breaking out of a turn to wings level was hit.

There would be no way to resurect the dead or examine the wreckage to discover the airframe was broken during a flick maneuver or bent in a hard turn above Va.

Facts are we will never be able to quantify that statistic. None of this changes the defined and measured characteristics of the aircraft nor does it invalidate the Operating Note warnings.

Where does he say only Mk 1 and II's?

The issue was solved in the Spitfire Mk V!!

You understand that the bob-weights and subsequent empennage changes to the design were to fix the instability??

It is only a factor in the early Mark Spitfires.

Aerodynamically, the instability is a very easy fix. The only reason it was not solved much earlier is the fact the Air Ministry had no defined standards for stability and control. Without measureable standards, the pilot stories of "easy to fly" simply overshadowed the few engineers who knew better.

[NZtyphoon]

Originally Posted by Crumpp

The issue was solved in the Spitfire Mk V!!

You understand that the bob-weights and subsequent empennage changes to the design were to fix the instability??

It is only a factor in the early Mark Spitfires.

Please provide documented evidence that Henshaw was only referring to Spitfire Is and IIs, otherwise this is just clutching at straws.

AA876 Vb 2223 EA M45 FF 25-10-41 during test flight 6-2-42 George Pickering reached a speed of 520mph in a dive. The aircraft disintigrated He was severely injured and never flew again. SOC before delivery not to be replaced. Airframe to RAE 9-4-42 for accident invest

MA480 IX CBAF M63 46MU 1-6-43 82MU 14-6-43 La Pampa 2-7-43 Casablanca 14-7-43 Middle East 1-9-43 Dived into ground Egypt FACB 10-10-43

[Glider]

We do seem to be in the normal situation where one side produces evidence to the best of their ability and often in duplicate. And the nay sayers produce nothing to support theirs and depend on ever more silly questions.

On the Bent wings waiting repair being a 1944 issue
1) An original document from the NA which is clear as to the cause of the problem in late 1944 and how to resolve it
2) the 2TAF series of books from C Shores a highly recognised author on aviation which also says the same

On the Bent wings waiting repair being a BOB issue
1) Someone says that they remember reading something somewhere
2) Crumpps statement with nothing to support it
In other words nothing

On the number of Breakups due to structural faiulure being small
1) A published work written by someone involved in Air Investigations for 50 years
2) The numbers matching those printed in the M S book
3) Henshaws paper the number are different but even lower

On the numbers of breakups being higher
1) I looked in the website but I asked because it's not written that's the only responsable of investigation but it's part of the entire Department.In otherwords the department has more responsibilities and this section is responsible for Air Investigations.
2) Statements that others may have come down at sea or in enemy held areas.
Of course this almost certainly happened. However its a question that we will never know the results to. Its something that happens to every airforce all we can do is do the best we can with what we know. In the same way we do not know how many of these had been damaged in combat.

[Al Schlageter]

So can we take it that Crumpp, given, the chance, would not pilot an early Mk of Spitfire as it was a death trap?

Notice they are all over the sky and even upside down.
http://www.youtube.com/watch?feature...&v=TXxzlOH92as

http://www.youtube.com/watch?v=c6c3v...eature=related