Sound barrier

Discussion in 'Aviation' started by Coors9, Oct 9, 2011.

  1. Coors9

    Coors9 Member

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    Who was the first ??? Was reading about Hans Mutke,He claims to have done it chasing a Mustang in a 262.
     
  2. vanir

    vanir Banned

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    #2 vanir, Oct 9, 2011
    Last edited: Oct 9, 2011
    Reputation is a fair consideration, but history likes documented references. Some US Navy pilots are documented above Edwards iirc, going supersonic in dives on the same afternoon the Bell X-1 exceeded the sound barrier in level flight. So navy boys in F-86 (or whatever their navalised proposed variant was called), are documented as first, the Bell X-1 as first in level flight.

    I have heard Mutke's claim do the traps at the Luftwaffe Experten board, if anyone would know they would and the consensus was a highly unlikely claim. There were several claims of breaking the sound barrier towards the end of WW2 but they are documented as falsified under test conditions in the same aircraft (eg. P-47C tested to this effect by Lindberg for the Army, this was his job during the war what a lifestyle hey; also P-38, Corsair, hell even the old P-36 Hawk were all tested according to regulation in near vertical power on dives, all nearly killed their pilots), the conclusions among test pilots (published) is that compressability and other aerodynamic effects, including structural failure was confused with exceeding the sound barrier, plus keep in mind things like wingtips can exceed the speed of sound well before the aircraft, if poorly designed for supersonic flight, and they will tend to rip off at about 0.87 sound for this reason.

    Also props don't like the sound barrier, or anywhere near it, iirc you can't get them past 0.88 sound, a Griffon Spit with laminar wings specially prepared did this once, but a Mustang is so clean the build quality generally so high they'll do about 0.87 sound out of the box iirc. But no other piston aircraft will get near it. And the 262 isn't structurally capable of tolerating transonic speeds either, it wasn't designed for it but may have a higher subsonic speed tolerance than straight wing contemporaries, supersonic compression would be delayed a little for the swept wings but keep in mind they weren't designed to do this, just an accident.

    Of course I'm posting on memory, someone else may correct my figures or points, but the general gist ought be fairly close.
     
  3. GregP

    GregP Well-Known Member

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    I don't believe there were any Navy boys flying F-86's. The XP-86 test pilot was George Welch, and he is said to have broken the sound barrier in the XP-86 the day before Yeager did in the X-1, but it is definitely not documented. It is all hearsay. Later it was proven the production F-86's, with an improved engine, could slightly exceed mach 1 in a dive, but since George wasn't supposed to be doing that, there were no recordings or test data backing it up, and no witnesses except at Pancho Barnes Happy Bottom Riding Club ... and that doesn't suffice to aviation records.

    The Me-262 has been proven several times to have been incapable of exceeding mach 1, even in a vertical dive under power.

    I think the Mile M.52 would have had a great chance, but the British mysteriously cancelled the program when the airframe was all but completed, and handed the research over to the USA. It must have been politics ... there is no other rational explanation.

    The D-558-1 wasn't a Mach 1 aircratf in level flight and the D-558-2 wasn't built at the time Yeager exceeded Mach 1.
     
  4. FLYBOYJ

    FLYBOYJ "THE GREAT GAZOO"
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    I lived in the Antelope Vally for a few years and met people who witnessed Welch breaking the sound barrier. A few are still with us today,
     
  5. Edgar Brooks

    Edgar Brooks Active Member

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    There was an article, on Welch v Yeager, in "Air Space" several years ago, but I couldn't begin to hazard a guess on the date.
    Edgar
     
  6. Gixxerman

    Gixxerman Member

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    #6 Gixxerman, Oct 10, 2011
    Last edited: Oct 10, 2011
    The story I have seen (a few times) is that the man responsible for the Miles project at the Ministry of War (as it then was) Sir Ben Lockspeiser was horrified at the possibility that this dangerous project was likely to kill a number of young British men just after the horrendous blood-letting of WW2.
    I have looked him up he was a veteran of WW1 so I don't think that mentality can be completely discounted.
    Geoffrey de Havilland, Jr's death was around this time quite a shock (and reinforcing the 'highly dangerous' and maybe the 'can't be done' reputation of the barrier)

    If we also factor in the dire financial situation Britain was in post-war and I can see why such a promising project was canned, however damaging or short-sighted the decision.

    Interestingly the (30%) scale model powered by a small rocket went to close to mach 1.4.

    As for the Miles people sharing data with Bell?
    Well it was supposed to be a reciprocal arrangement from what I've read we showed ours but Bell never did show their research.

    (wiki does mention Sir Ben Lockspeiser was known to have an interest in communism after the war - but there is no suggestion he acted to stop the Miles project on behalf of foreign agents etc etc)

    As for the Me 262, vanir GregP are right.
    The swept wing on the Me 262 was a fortunate accident, it was done for a C0G change; the benefits delaying transonic shock etc were recognised later.
    Fundamentally the wing just isn't strong enough (and I am sure I've seen somewhere that it isn't of the right aerofoil section either).
    I am certain that I've read that post-war tests in the UK USA proved that before mach 0.9 is reached the aircraft went totally out of control with all control surfaces becoming ineffective.
     
  7. GregP

    GregP Well-Known Member

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    Flyboyj,

    Did these people withess the event before Yeager's flight, on the same day, or did they witness it in the course of F-86 testing some time later? ... you didn't mention the date ...

    Did any of them have any recording devices and were they using them to document the event? Not a sarcastic question here, just asking if there is any record of it other than people saying it. Nobody will likely change the records as they now stand without some pretty solid proof.

    We all know Welch dived down right above Barnes' club, but a jet whipping by close doesn't mean it is supersonic. In fact, neither the XP-86 nor the production F-86's were superconic at low altitudes, even after a dive. If it was supersonic, it was at about 18.000 feet and above in a power-on dive, and not much above Mach 1 at that. The sonic boom would have followed the aircraft down and probably caught up with the Sabre about the time the Sabre passed through 5,000 feet or so on the way down as he pulled out.

    I have heard many people describe a close encounter with a jet as "supersonic." Several were with me once when we were in Alaska outside anchorage and had a F-15 pass us in a supersonic departure out of Elmendorf AFB. They seemed astonished at a real supersonic boom, though most had said previously they were familiar with the sound of supersonic flight. In reality, they weren't.

    The only reason I knew a supersonic boom was that I used to live in Tennessee, and we were located in a supesonic corridor in the 1960's. So we got sonic booms from time to time, mostly from F-4's, sometimes from unidentified aircraft, and I once got passed at low level by an F-104. At first I thought he was supersonic because the noise got very loud as he went over. Later I realized he passed over me (actually "us" on dirt bikes), engaged afterburner about that time, and pulled up into a steep climb. To say he surprised us is an understatement! One guy went down on his dirt bike ...

    If not for that experience as a kid and highschooler, I might also not have known what a sonic boom sounded like up in Alaska when we were there in 2001 or so.

    Absolutely no disrespect towards your friends in the valley, and I'm not saying or trying to imply they were wrong, either. Just asking some clarifying questions and relating my own exeprience with people who said they knew what they were talking about.

    On a side note, perhaps you could relate some other stories from Antelop Valley you might have heard over time from some of the old timers? They are always treasues of aviation lore, and almost always unusual ... or they would not have stood out in the minds of the people at the time to be remembered years later.
     
  8. FLYBOYJ

    FLYBOYJ "THE GREAT GAZOO"
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    #8 FLYBOYJ, Oct 10, 2011
    Last edited: Oct 10, 2011
    Hi Greg - according to these folks Welch blasted over Barnes' place and then climbed to altitude. It was after that where they heard "the boom." Some of them claimed that Welch actually knew the XP-86 would exceed the sound barrier (even with the original engine) and planned to do so because he didn't like Yeager (I was told that Welch had a very grumpy side to him, again just local here-say). One of the eye-witnesses I knew real well claimed to witness this passed away in 2002. He worked for NA and said that Welch gave some sketchy comments to the NA mechanics servicing the aircraft that he was going to do this, but never came out and said it or admitted it after it was done. I met a least 2 other people who claimed to be there and witness this as well.

    The rest of the story was second hand but it seemed to match what "Larry" told me. Might be BS, folklore or the truth, but it lingered around the Antelope Valley for over 60 years.
     
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