Placing the Bell P39 Aircobra.

[Jukka Juutinen]

If Spits did not use vertical dives (not that BS of 60 deg as "vertical"), then why is that mentioned in the Spitfire bible? It is mentioned on the section dealing with complaints of wrinkled wings in Spit IX fighter bomber ops. It is clearly mentioned that most wrinkling was experienced by pilots who dove vertically (not at 60 deg) and pulled out hard at low altitude and escaped at tree top level.

[tcolvin]

Originally Posted by Kutscha

Actually your interpretation of vertical dive is wrong. Typhoons pilots found that by making a steeper dive than they usually did with bombs increased the accuracy of the RPs. This was not vertical, but like the Spit's 60* angle it felt like it was vertical.

This is not my 'interpretation' of anything. It is what the practitioners say they did - time and again.

Just one example; "With bombing we liked to roll over and go down vertical style. You could get a fair old speed up, and one got quite good at it in the end". Flight Lieutenant A.G. Todd, 164 Squadron. Quoted in 'Typhoon Attack', by Norman Franks, page 75.

"We usually rolled in at 1,000 feet and pulled out at 6,000 feet so as to beat the flak. ...In echelon we usually slowed it up to 230 mph on the clock, pull it up at the last minute, and in the Typhoon 230 is slow; it only cruised at 280, so it was sluggish at 230. Then as the Typhoon ahead of you went over, you just rolled and kept the nose up till your speed had dropped a lot, because if you went in at speed you'd pull your wings off, as by then you'd be going straight down, and it got up one hell of a lick! .... it went down like a brick, and in the dive you had to line up on the target. You put your gun-sight on and you'd pull your vertical line on the sight through the target, and as it disappeared under the nose, just drop your bombs. That's as accurate as you could get, taking no account of wind but making sure the target was far enough under your nose. I'd say it was pretty accurate, and you'd probably hit the target". Sergeant R.W. Cole, 3 Squadron, page 57 of Norman Franks' book already cited.

Cole probably didn't hit the target, but that is not the point. He tried his best, and his best was vertical.

Tony

[Graham Boak]

You can wrinkle a Spitfire's wing - or indeed most fighter's wings - by pulling too much g. You don't have to be vertical, or anywhere near it. However, in a steep dive the acceleration is such that you can readily exceed limiting speeds (and approach limiting altitudes!) and then have to pull the excessive g to recover. The Spitfire was an older design with a thin wing, which did not have the intrinsic strength of thicker sections. It was strengthened with the Mk.Vc, or universal wing, but experience with the pointed-wing Mk.VIIIs also lead to excessive wrinkling in air-to-air combat at lower altitudes. Despite its virtues elsewhere, the Spitfire was not an aircraft to go dive-bombing in.

Did pilots go vertical in the Typhoon - probably, although almost certainly less often than is claimed. Did this make them more accurate? Very doubtful indeed. If accurate dive-bombing was possible without airbrakes, then why did specialist aircraft have to have them?

[Jukka Juutinen]

Possible more able pilots are able to benefit from the vertical dive while the average one needs more time afforded by dive brakes.

[Kutscha]

Originally Posted by Jukka Juutinen

If Spits did not use vertical dives (not that BS of 60 deg as "vertical"), then why is that mentioned in the Spitfire bible? It is mentioned on the section dealing with complaints of wrinkled wings in Spit IX fighter bomber ops. It is clearly mentioned that most wrinkling was experienced by pilots who dove vertically (not at 60 deg) and pulled out hard at low altitude and escaped at tree top level.

Better read again. Note the 45* to 60* angle mentioned.

pg 329 and pg 330 of the Spit bible

Farnborough Nov 1944. V-g records for Spitfire Mk IX during operations in France and Belgium. A number of V-g recorders were installed in a/c of a Spitfire Mk IXLF Wing on the Western Front , in order to investigate skin wrinkling on mainplanes. Spitfires of No. 125 Wing had experienced a large number of buckled wing within the space of a couple of weeks. A/c involved in the tests were:- NL345, NH476, PT357 The 2 forms of attack suspected of causing wing damage were armed recon and dive bombing. For bombing one 500lb bomb was carried under the fuselage and two 250lb bombs under the wings. The pilots generally dived into the target at an angle of 45* to 60*. Lowest altitude reached was about 1000ft choosing one vehicle and diving across the road and not along it. After the attack the Spitfires were climbed immediately out of range of the heavy flak using rapid aileron rolls, weaving, tight turns and inverted flight. Escape low down was nor favoured as the flak could concentrate easily at that height. The pull out was considered severe and black out, a common occurance, was ignored.

Also see pg 316 and pg 317 where it again mentions 45* and 60* dive angles and some are said to be almost vertically. Note the 'almost'.

Tony, you to note the 'almost'. As well, the target would not disappear in a vertical dive though it would in a high angle dive.

[tcolvin]

Originally Posted by tcolvin

"We usually rolled in at 1,000 feet and pulled out at 6,000 feet so as to beat the flak. ...

Sorry. For 1,000 feet read 10,000 feet.
Tony

[tcolvin]

Originally Posted by Kutscha

For bombing one 500lb bomb was carried under the fuselage and two 250lb bombs under the wings.
Also see pg 316 and pg 317 where it again mentions 45* and 60* dive angles and some are said to be almost vertically. Note the 'almost'.

Tony, you to note the 'almost'. As well, the target would not disappear in a vertical dive though it would in a high angle dive.

Please explain your note to me in the light of;
a) these are Spitfires not Typhoons. They were not necessarily flown the same, and pilots did not switch from one to another from sortie to sortie.
b) Spitfires did not carry RPs.
c) Spitfires carried the large bomb under the fuselage. Therefore they could not drop from the vertical because of hitting the propeller arc.
d) IIRC it was only in a vertical dive that you made the target disappear under the spinner.

Tony

[tcolvin]

Originally Posted by Graham Boak

Did pilots go vertical in the Typhoon - probably, although almost certainly less often than is claimed. Did this make them more accurate? Very doubtful indeed. If accurate dive-bombing was possible without airbrakes, then why did specialist aircraft have to have them?

Because it was hairy and dangerous to dive a fighter without air brakes as the wings would come off over a certain speed.

The point is this. Accuracy required vertical delivery. The RAF refused to operate aircraft designed for vertical delivery. Typhoon pilots wanting accuracy delivered from the vertical nevertheless. Therefore the RAF are condemned of supplying the wrong equipment. QED.

[Kutscha]

Did you miss the part where Spits carried bombs beneath the wings. Hard to to put a bomb through a prop when dropped from that postion.

Think instead of parroting. An a/c shooting at an a/c (target) directly in front of it does not have the a/c (target) disappear. Now, if the shooting a/c pulls some lead, then the a/c (target) will disappear.

An a/c flying horizontal has the ground target disappear at a certain distance (speed, height and cowling size dependent). Depending on the a/c, the angle the a/c is flying (ie dive angle), this distance will decrease until the a/c is vertical/perpendicular.

So the a/c could not be vertical if the target disappeared.

A dictionary should be able to help you with the word 'almost'.

[Jukka Juutinen]

Kutscha, 60 deg cannot be described as "almost vertical". Or would you describe 6000 euros as "almost 9000 euros"???