Warbird Information Exchange

So since its 60yrs since Mach 1 was broken officially.. here some questions.

In ww2 it was known that mach 1 was broken in a dive in various planes. So this didnt count?

The first plane to really break Mach 1 in level flight was the F-100 / Mig19?

The Bell X-1 doesnt count as it is purely a JET rocket aircraft,not a jet engine aircraft. I find this is mostly overlooked by ALL when they discuss the topic.

The F-86 could break Mach 1 again only when in a dive.

So what do you all think of the issue?

Should Mach 1 be claimed by a pure jet engine or a rocket aircraft?, rembering rocket aircraft is a totally different bird of prey let alone not a real jet in my lines of thinking.

Depends on your question. Most people accept that the Bell X-1 was the first aircraft to break Mach-1 in level flight and under control, as well as under test conditions able to validate the claim. That's why (most) earlier claims aren't regarded as 'the record', either control or validation were issues.

The dive vs level flight issue is a different one of course. I think we'd agree that the aircraft we are looking to 'recognise' as achieving Mach-1+ needs to do it under it's own power, not requiring gravity, although that data, for aircraft going Mach-1 in a dive is of interest as an aerodynamic achievement and powerplant shortfall.

Incidentally, the Bell X-1 isn't eligible for the official Fédération Aéronautique Internationale (FAI) record as it didn't take off under its own power, and was air launched; quite reasonably, for any records, the FAI expect the aircraft do be able to do the whole task. Doesn't invalidate the achievement though.

The power plant of the aircraft is irrelevant IMHO, unless you are asking for the 'first Mach-1 jet aircraft'. If it was powered by an elastic band and did the job, it'd still have the record. (As well as a pilot with a very strong winding finger...)

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James K

"Switch on the underwater landing lights"
Emilio Largo, Thunderball.

www.VintageAeroWriter.com

I'll think you'll find this isn't known at all.

IIRC, the Spitfire has the highest critical mach number of aircraft from that era at just over 0.9 Mach.

People who understand far more than me, which isn't difficult, have stated the claims to be impossible.

The Navy claimed that the X-1 couldn't tkaae off on it's own power, but Yeager himself did pilot it on a take off. The main reason this was dangerous was the fragile landing gear wasn't desinged to hold the weight of a fueled aircraft.

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Chris Henry
EAA Aviation Museum Manager

Am I allowed to post on this thread?

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Don't touch my junk!!

Jack I think you should be allowed to post on this subject as long as you don't mention George Welch...

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Zane Adams
There I was at 20,000 ft, upside down and out of ammunition.
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Well that sucks Can I mention Pappy B.

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Don't touch my junk!!

Do we get to talk about Yeager being an a$$hole in this thread...just to make it a WIX 'hat trick'?

To use a quote from a John Wayne movie.

"When the legend becomes fact, print the legend."

Hence, Yeager was the first to break Mach 1.

Bill

I know Mudge likes them Duke movie quotes.

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Bill


Website

how's this..............
NAA test pilot/insert name/ did it first

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Don't touch my junk!!

Re Spitfire dive mach numbers. First I have read some silly stories, ie P-38 in a 600 or more mph dive, P-47 over .9 mach.I don't believe any WWII prop plane dove over Mach I. I have heard Yeager and/or Hoover say a Mustang had a higher mach crit number than a Spit, I believe about .82. My Spitfire Pilot Notes, par 52 clearly lists max dive speed as .85. This is not a test plane , but a fully armed and operational fighter. I have heard that in service this was extended slightly to .88. Famed Test Pilot Alex Henshaw wrote that he test dove Spits to .89. Two other pilots took an unarmed recon Mk XI (Merlin) to over .9 mach. There was no problem with the wing, luck or genius or both got this right; but both times the prop backing plate or gears failed. The first time the pilot was able to glide to a safe landing. The second time at mach .92 the failure was severe and the pilot was killed. They did not try more tests. I don't know how accurate all the instruments were in each plane, it is logical that the Bell X-1 may have had the best of that. I was recently offered to trade some Spitfire time for a ride in that space plane. Don't now how sincere or realistic that offer was, but it made me think. I guess I am kind of fond of Earth's atmsosphere.

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Bill Greenwood
Spitfire N308WK

Bill,
Read Al Blackburn's book on the mach race it's excellent. It's really a great book. He states the Spit had the greatest mach limit. He also noted the the X-1 group slowly crept toward mach 1 while Welch (oops!) had no fear of it what so ever. He'd watch the V-2s bust mach repeatly with no problem at White Sands. I find it funny that on his second trip through the speed of sound he boomed Pacho's and dove past Yeager who was just releasing from the B-29!!

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Don't touch my junk!!

Whats wrong with mentioning George Welch?


I've always wondered if he broke it. Its a good possibility that he did.

I think George Welch is probably one of the underestimated pilots around. Kinda neat to know he was one of the few pilots off at Pearl Harbor...in a P-40 no less.

Cheers,
Nathan

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To return briefly to the WW2 era...

There are 3 very high-speed dives in Spitfires that I'm aware of without poring through books.

Two were conducted by the same chap, Sqn Ldr Tony Martindale (I think), at Boscombe Down. I think they were reported as 0.92M and both times he lost the prop and reduction gear. He succeeded in landing the aircraft and the first time he got away with it but the second time he suffered serious back injuries and had to retire.

The other flight was related in a couple of articles in Aeroplane Monthly a few years back. It was a PR.XIX flown by Flt. Lt. E Powles from Singapore or Hong Kong. I can't recall why now but he dived from very high altitude, 35 or 40,000 feet, and claimed to have reached a speed of 0.94 or 0.96M.

I can't remember now if it was proved to be that fast or not.

Didn't I read somewhere that one of the Convair jetliner designs (880, 990, 990A, etc) exceeded Mach 1 in a dive during flight testing? Have any other "intended to be subsonic" jet airliners ever gone past Mach 1?

Those Convair jetliners sure were pretty to look at, and darned fast, too!

Cheers!

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Dean Hemphill, K5DH
Port Charlotte, Florida