Spitfire structural failures

[GScholz]

The mention of the 10G limit was in the first post in this thread.

[VO101_Isegrim]

Originally posted by GScholz
The mention of the 10G limit was in the first post in this thread.

Ah, I see. Appearantly that 10G is kindofa 'breaking point' for the airframe, not a 'safe' load factor. It seemed awfully high to be of the latter kind.

What I know for 109s, there was some testing of that, I think HoHun posted the details a while ago.

[GScholz]

The 109s could take 12Gs before breaking.

[Nashwan]

Two Spitfire wing were tested, one failed at 12.3 G, one at 13 G. Spitfire The History, p57

[mw]

Flying Limitations of the Spitfire IX (from Pilot's Notes)
Maximum speeds in m.p.h I.A.S.
Diving (without external stores), corresponding to a Mach No. of -85:


Between  S.L. and 20,000 ft. -450  
  20,000 and 25,000 ft. -430  
  25,000 and 30,000 ft. -390  
  30,000 and 35,000 ft. -340  
Above  ..................35,000 ft. -310  

Flying Limitations of the Me 109 G (From Technical Instructions of the Generalluftzeugmeister, Berlin, 28th August 1942.)

Reference Me 109 - wing breakages.  Owing to continually recurring accidents caused by wing breakages in Me 109 aircraft attention is drawn to the following:

.......(1) The maximum permissible indicated airspeeds in the different heights are not being observed and are widely exceeded. On the basis of evidence which is now available the speed limitations ordered by teleprint message GL/6 No. 2428/41 of 10.6.41 are cancelled and replaced by the following data:


Up to 3 km (9,842 ft.) 750 km/h. (466 m.p.h.)  
At 5 km (16,404 ft) 700 km/h. (435 m.p.h.)  
At 7 km (22,965 ft) 575 km/h. (357 m.p.h.)  
At 9 km (29,527 ft) 450 km/h. (280 m.p.h.)  
At 11 km (36,089 ft) 400 km/h. (248 m.p.h.)  

.......These limitations are valid for the time being for all building series including the Me 109 G. A corresponding notice is to be placed upon all air-speed indicators in aircraft.

.......(2) Yawing in a dive leads to high one-sided wing stresses which, under certain circumstances, the wing tip cannot support. When a yawing condition is recognised the dive is to be broken off without exercising force. In a flying condition of yawing and turning at the same time correction must be made with the rudder and not the ailerons. The condition of wing tips is to be examined and checked with TAGL. Bf 109 Nos. 5/41 and 436/41.

.......(3) Unintentional unlocking of the undercarriage in a dive leads also - especially if only one side unlocks - to high wing stresses. Observation and the carrying out of TAGL. No. 11/42 and the following numbers is, therefore specially important.
Note. Trouble has been experienced owing to undercarriage unlocking in a dive and a modification has been brought out to prevent this.

.......The dive speed limits listed above are also to be found in Vorläufige Fluggenehmigung BF 109 G-2 and G-6

Dive limitations from: Bf 109 G-2, G-4, G-6 Bedienungsvorschrift, June 1943 edition

.......Dive: Adjust trim in such a way that the airplane can be held in a dive. The elevator forces and tailplane loads become great at high speeds. The tailplane adjustment must work perfectly; otherwise shifting of the tailplane is possible.
Sturzflug: Trimming so einstellen daß das Flugzeug durch Drücken im Sturzflug gehalten werden kann. Die Höhenruderkräfte und Flossenbelastungen werden bei hoher Fahrt sehr groß. Hemmung der Flossen verstellung muß einwandfrei arbeiten; sonst ist Selbst verstellung der Flosse möglich.

.......Maximum diving speed 750 km/h. Hard aileron manipulation while diving leads to failure, particularly when pulling out. Höchstzulässige Sturzfluggeschwindigkeit 750 km/h. Harte querruder betätigung im Sturz und besonders beim Abfangen führt zum Bruch.

http://www.fourthfightergroup.com/eagles/spit9v109g.html

Mach .89 Spit Thanks Neil!

[Crumpp]

Dive speed table from the handbook:
It is the same table for all the FW's from the A-1 to the A-9 Jabo or Jager.  There is a second table which reflects the same as the 109 depending on the AIRSPEED indicatior.  

0-2 km - 850 kph

3 km - 800 kph

5 km - 700 kph

7 km - 600 kph

9 km - 500 kph

Below 5 KM ASL the FW-190 was faster in a dive up to a max of around 50 mph. At 29,527 feet the Spitfire Mk IX had a 30 mph speed advantage once it overcame the FW's initial dive acceleration.

Keep in mind too that the RLM left it up to the manufacturer to test dive speeds.  Very few high speed trials were conducted.  The 109 and the 110 are the only two Luftwaffe A/C I can say for sure had trials done.  Both test pilots recieved 10000 Reichmarks for the test dives at a time when a loaf of bread cost .02 Pfenning.
Crumpp

Crumpp

[VO101_Isegrim]

109 F/G dive trials. Comparison of safe dive speed limits in 1943.



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


Underlined by the combat experience of US pilot Robert C. Curtis  :


"My flight chased 12 109s south of Vienna. They climbed and we followed, unable to close on them. At 38,000 feet I fired a long burst at one of them from at least a 1000 yards, and saw some strikes. It rolled over and dived and I followed but soon reached compressibility with severe buffeting of the tail and loss of elevator control. I slowed my plane and regained control, but the 109 got away.

On two other occasions ME 109s got away from me because the P 51d could not stay with them in a high-speed dive. At 525-550 mph the plane would start to porpoise uncontrollably and had to be slowed to regain control. The P 51 was redlined at 505 mph, meaning that this speed should not be exceeded. But when chasing 109s or 190s in a dive from 25-26,000 it often was exceeded, if you wanted to keep up with those enemy planes. The P 51b, and c, could stay with those planes in a dive. The P 51d had a thicker wing and a bubble canopy which changed the airflow and brought on compressibility at lower speeds"



Butch2k:

"109 wing torsion is similiar to what could be found in US fighter planes. No aileron reversal at high speed, which came as a suprise to US engineers in charge of evaluation the 109 aerodynamic properties."


Guppy35


"No question that the 2 250 pounders and 1 500 pounder was used extensively pre and post D-Day. 453 RAAF Squadron and 602 Squadrons were doing this pre-D-Day and many of the IX and XVI squadrons on the continent were flying ground support in this configuration.

One of the problems at the time was if the bomb did not seperate from the plane. Spits were losing wings that way. "





Bf 109 K dive limits from K-4 Handbuch.



Notice the the dive limits are the same, 527 mph, with underwing cannon gondolas weighting over 500 lbs, or clean.

For comparison, Spitfire Mk XIV maximum dive limits (w/o external stores) :

Between S.L. and 20,000 ft. - 470 mph
20,000 and 25,000 ft.           - 430  mph
25,000 and 30,000 ft.           - 390 mph
30,000 and 35,000 ft.           - 340 mph


Banning of dive bombing operations on the Spitfire Mk VIII, due to structural weakness, 14th August 1945 :


"Signal T.783 from RAAFHQ advising due to defect reported from overseas spitfire Mk 8 a/c are not to be used on operations involving dive bombing or low attack."


http://www.x-plane.org/users/isegrim/FvsF/7-diveprohibition.jpg

http://www.x-plane.org/users/isegrim/FvsF/9-MkVIIIdive-restriction.jpg

[Guppy35]

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.

Happy now?

Dan/Slack

[VO101_Isegrim]

Never said the Spitty was a lousy plane, or a bad aircraft.
IMHO it`s the only thing ~equal/closest to the 109 in ETO.

Just for the record. Oh, and BTW, reverse your post and you got what Mr. Mike Williams is thinking/propagating with questionable means.

[Guppy35]

Originally posted by VO101_Isegrim
Never said the Spitty was a lousy plane, or a bad aircraft.
IMHO it`s the only thing ~equal/closest to the 109 in ETO.

Just for the record. Oh, and BTW, reverse your post and you got what Mr. Mike Williams is thinking/propagating with questionable means.

OK then get something straight.  What they did with combat aircraft from both sides during the war often as routine exceeded the manuals.  

Go check up on the bombers guys.  They routinely took off far over max weight because the mission demanded it, and in wartime the risks involved in exceeding the manual were worth it.

As for Spits.  You'll have to define a rough airfield for me then.  Those Spits are operating from PSP fields, put up by the engineers on the continent.  They were not concrete runways.  

Keep in mind that because of that as the Spit IX/XVI was moved into the ground attack role, the wing was strengthened in particular because of the addition of the wing hard points.  This was of course in the 44-45 time frame not 42-43

Clarifying it better. The strengthend wing was obviously the "E" Wing.  As you can see in the photos, the Spits with the three bombs on seperate hardpoints are E wings.  

The wing failures when bombs failed to come off, were pre D-Day with Spit IXs using Universal wings, as in those with the 2 20mm and 4 303s.

You don't see E Wing Spits until right after D-Day for the most part.

Dan/Slack

[Guppy35]

Originally posted by VO101_Isegrim
Never said the Spitty was a lousy plane, or a bad aircraft.
IMHO it`s the only thing ~equal/closest to the 109 in ETO.

Just for the record. Oh, and BTW, reverse your post and you got what Mr. Mike Williams is thinking/propagating with questionable means.

Forgot to reverse the post.

The Spitfire was a great airplane, that was loved by the pilots who flew it.  It shot down a lot of enemy planes and accomplished the missions it set out to do.

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

The Luftwaffe lost the war and all their aircraft.

What part of that statement isn't true?

Dan/Slack

[GScholz]

Originally posted by Guppy35
Forgot to reverse the post.

The Spitfire was a great airplane, that was loved by the pilots who flew it.  It shot down a lot of enemy planes and accomplished the missions it set out to do.

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

The Luftwaffe lost the war and all their aircraft.

What part of that statement isn't true?

Dan/Slack

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.

[Angus]

The Luftwaffe lost the fight.

Not a quality issue though.

[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.

[F4UDOA]

Is this IAS or TAS?

BTW,

The porposing issue with the P-51D was resolved by the use of a dorsal fin. The same occured in the P-47 when switching to the bubble canopy.

What is the critical mach of the 109K?