Spitfire structural failures

[Crumpp]

Pretty sure that is IAS.  A 109F2 WrkN 9228 flown by Heinrich Beauvais reached 906 TAS which comes out to around 750 IAS (mach .80).  Makes sense the 109K could outdive the 109F2.

Crumpp

[Wotan]

As I understand the definition of critical mach varied. Critical mach is not the same as maxium achievable mach or as maximum tactical mach.

Just comparing factory limits can lead to inaccurrate conclusions.

Critical mach number of fighters like the P51,  Spit, 109  and 190 was around .75, while it was around .70 for the P-47D and around .65 for the P-38.  

Maximum achievable mach was about .73 for the P-47D (without dive flaps) and  .79 for the 109.

Tango and Hohun discussed Critical Mach in several threads. The info in my reply comes from these threads.

[Crumpp]

The officially laid down dive limit could be exceeded by 200 km/h IAS in these tests w/o an damage to the aircraft.

I don't think it could Barbi.  I believe you are confusing IAS with TAS.  

Crumpp

[Guppy35]

Originally posted by GScholz
Nothing is wrong with that statement, it is true. So is this one:

The 109 was a great airplane, that was loved by the pilots who flew it.  It shot down more planes than any other fighter in history.

It was well built, with one of the best engines ever made.

The Luftwaffe did not lose the war and all their aircraft because their aircraft were inferior.

And therin lies the seemingly unconquerable problem with these threads.  Somehow, liking Spits for example, to some means that that person must hate 109s.

Having an interest in both is not impossible.

But again, somehow it becomes this big debate about which was better.

They both did their job, were respected by their foes, appreciated by their pilots and were well built with quality powerplants.

So there!

I like em both.

Dan/Slack

[Guppy35]

Originally posted by Wotan
They didn't loose the fight to the Spitfire, that's for sure. LW pilots ran up huge kills against Spits. Both in the 109 and 190 over Western Europe and NA. Hell, look at Deippe where the allies had numbers over JG 2 and JG 26,

Here count umm up...

http://fw190.hobbyvista.com/dieppevictories.htm

If LW planes were deficient or bettered by Spit engineering then what does that say about the Spitfire pilots? If there aircraft was so good you think it would stand out. The 109 was more then a match for the Spitfire.

Priller shot down 69 Spitfires alone.

Here's a list of the top Spit killers:

http://www.luftwaffe.cz/spit.html

Germany lost the war but not at the exclusive hands of Spitfire pilots.

So yeah the LW lost. It took the combined strength of the VVS-RKKA and the USAAF to achieve this.

Relax Wotan.  No one said that the LW lost the war to the Spitfire alone.  No one said that the 109 was a hunk of junk.

I merely responded to the statement isigrim made about reversing my original statement.

Jeez you guys.  They were both  good aircraft.  Relax for heaven's sake.  You'd think I'd insulted your mother.

Dan/Slack

[Nashwan]

Is this IAS or TAS?

Judging by the title it's IAS. However, 800 km/h IAS at 11 km is around mach 1.4, at a guess. (don't have the stuff to check it now)

[GScholz]

No, 800 kmh is a little less than 0.8M. Kmh is easy that way. 1M is just over 1000 kmh (Edit: at 30,000 feet)

[gripen]

That Bf 109K dive chart is for "Fahtmesser höhenkompensiert" ie the speed meter had compensation for altitude. In practice this means that these values are not comparable with normal IAS values (except at sea level).

Regarding g limits, people are  mixing things here quite badly. Most WWII fighters were originally designed for breaking load factors well over 10g and safe load factors were normally around 6-8g (depending on standard) at given weight. As an example the Mustang was originally designed for safe load factor 8g at weight 8000lbs with safety coefficien 1,5 ie the breaking load factor was 12g. At higher weight load factors are naturally lower; the weight of the Mustang (just like weight of the Spitfire and Bf 109) raised during production for various reasons, therefore safe load factor decraesed and but  It should be noted that the planes rarely reached their safe limits in practice. In the case of the Bf 109 the airframe was strenghtened several times after last major redesign (Bf 109F) and same is certainly true for the Spitfire.

The dive limits had nothing directly to do with max loading factors. The main limit was critical mach number ie the mach number were the compressibility effects started (buffeting, porpoising, dutch roll or what ever). In the test conditions many planes certainly reached higher mach numbers, as an example that Bf 109 which reached mach 0,8 was not a standard plane but a Bf 109F/G hybrid with revised aileron throw and ejection seat. The test pilot, Lukas Schmid (see "Test Pilots" by Wolfgang Späte ), noted that without revised aileron throw  he would have probaly died; the Bf 109 developed strong dutch roll motion above it's critical mach number which is about mach 0,76 according to German documentation and that fits also quite nicely to it's dive limits.

Regarding aileron reversal speeds, according to DVL tests the Bf 109F had aileron reversal speed about 1000km/h at 3km (about 620mph at 10k). As for comparison RAE tests give:

Fw 190 750mph
Mustang I 850mph
Mustang III 880mph
Spitfire V 580mph (standard wing)
Spitfire V 660mph (clipped wing)
Typhoon 740mph

gripen

[GScholz]

The last major redesign of the 109 was the G, not the F. There were significant structural changes made, both to strengthen the airframe and to increase production.

[Crumpp]

Gripen,

Do you have a copy of these test?  I would like to see them.
Thanks.

Crumpp

[gripen]

GScholz,
Main differences from the structural viewpoint between the Bf 109G and F were just thickness of the materials and reinforcements in the critical points (namely around wheels in the wings), the F-4 being closer the G-2 than F-2.

Crumpp,
The numbers are mostly from the RAE 1231, for the rest you should be just patient (or find them yourself).

gripen

[Wotan]

Originally posted by Guppy35
Relax Wotan.  No one said that the LW lost the war to the Spitfire alone.  No one said that the 109 was a hunk of junk.

I merely responded to the statement isigrim made about reversing my original statement.

Jeez you guys.  They were both  good aircraft.  Relax for heaven's sake.  You'd think I'd insulted your mother.

Dan/Slack

You are the one that has taken up the "I am offended attitude".

I give. THe Spit was a lousy airplane, that every pilot who ever flew hated. It never shot down anything. It didn't accomplish one mission it ever set out to do.

It was weakly built with one of the worst engines ever made.

The Luftwaffe won the war without the loss of a single aircraft.

What’s this about?  

Angus and you brought up "well the Luftwaffe lost the war" as apart of your argument on "how good" you think the Spitfire was. Why bother making such statements if you aren’t implying something?

In a thread about Spitfires if some resorts to "well the Luftwaffe lost the war" an easy, reasonable rebuttal is "well not to the Spitfire". If that bugs you why mention it at all?

[Crumpp]

The test pilot, Lukas Schmid (see "Test Pilots" by Wolfgang Späte ), noted that without revised aileron throw he would have probaly died; the Bf 109 developed strong dutch roll motion above it's critical mach number which is about mach 0,76 according to German documentation and that fits also quite nicely to it's dive limits.

Only on the last dive did Schmid lose the stick for a second. Yes in that instance the stops saved him from disaster. He tested the 109 from Jan to Mar. 1943.  From 850-890 kph an "overbalance" developed according to the reports but it was not hard for the pilot to deal with it nor did it spell disaster for a "normal" 109.

Several sources list Mach .80 as the mach number of the 109.  Including Schmid.

Your Post Gripen seemed somewhat misleading so I thought it needed some clarification.

Crumpp

[Guppy35]

Originally posted by Wotan
You are the one that has taken up the "I am offended attitude".

 

What’s this about?  

Angus and you brought up "well the Luftwaffe lost the war" as apart of your argument on "how good" you think the Spitfire was. Why bother making such statements if you aren’t implying something?

In a thread about Spitfires if some resorts to "well the Luftwaffe lost the war" an easy, reasonable rebuttal is "well not to the Spitfire". If that bugs you why mention it at all?

Go back, read it again, note smile at the end of the original "Spit was a lousy airplane" paragraph.

I was responding to isigrim.  He then makes the comment about reversing that "Spit was a lousy airplane" paragraph so I did at which point my original "the Luftwaffe won the war without losing a single aircraft"  became the Luftwaffe lost the war etc.

You seemed to take that very seriously, and you seem to take it as some sort of insult to the 109, at which point I then am asking why folks have to hate one of the two if they like the other.  And then I said I liked both the Spit and the 109, that they were both good aircraft and both did their jobs well etc.

What part of that don't you get?  And how does that make me offended by any of it.

To be honest I think it is rediculous how any Spit thread had to degenerate into how the LW aircraft were better, and any 109 thread has to become how the US or RAF aircraft were better.

So maybe you ought to turn of your LW sensitivity meter.

Dan/Slack

[gripen]

Crumpp,
This is pretty damn simple, Schmid reached mach 0,8 with a specially prepared plane and he had problems. For one reason or another you and Isegrim want to claim that speed as safe limit. Using same logic I could claim mach 0,86 as safe limit of the P-47 because an instrumented plane reached it without damage (according to documentation).

gripen