The Sound Barrier
 

As I thought the spin-off discussion on early supersonic flight was getting interesting I thought I'd give it an outlet...If anyone is interested!!!
Although I agree completely with the assertion in Camel Pilots post in the Lindberg v Armstrong thread that the M52 would never result in a supersonic fighter it wasn't ever supposed to as it was purely a research vehicle. However to describe it as 'wierd' as I.M.Esperto has done is unfair. Miles were a company known for investigating unusual and advanced techniques on a very small budget and the M52 was a typical example of this. wether it was a dead-end or would have resulted in the first supersonic aircraft...Well, we'll never know! The X1 was a less ground breaking basic design but it was designed that way to achieve it's purpose..supersonic flight and there is no doubt that this is what it did achieve. I was fascinated to find out it was built to +18/-18g! But that little appeared to have been learned in the use of rocket fuels and organic based lubricants and that a number were destroyed in resultant explosions!

What do you guys think?
Spiney

Yes, interesting stuff indeed.
Just digressing even further if I may, I was wondering if anyone knew what the first Soviet supersonic aeroplane was? I haven't been able to find out anything about it specifically.

Perhaps yet another new thread on Barnes Wallis as well? ;)

Hi 18-Wheeler.
Soviet supersonic aircraft research is interesting indeed, and as you say, accurate information seems hard to come by. There were certainly rumours, (but no hard evidence), that the USSR first exceeded Mach 1 in May 1947 using a copy of the German DFS 346. This was a swept-wing, dual rocket powered research aircraft designed to achieve Mach 2.65 at 114,000 ft! A huge amount of DFS research fell into the hands of the USSR at the end of the second world war and so did some of their research scientists and the DFS test pilot, Wolfgang Ziese. DFS were a fascinating company in that they developed from a glider manufacturer to a serious research organisation involved with supersonic and stratospheric flight. I'm not aware of any books specifically about their work but if one exists it would certainly be a good read!
Being the type of society that it was in the late 1940's, the USSR can best be described as having a 'distorted' view to reporting facts accurately and it's very unlikely that the DFS 346 did fly supersonically in that country. It would appear that the first supersonic Soviet aircraft was the Lavochkin LA176, which was supersonic in a dive and was designed to be the worlds first truly supersonic fighter but in fact was quickly superceeded by better designs. The first published date I've seen for the LA176 going supersonic is 26th September 1948. I stand to be corrected on this however!

Spiney

Supersonic flight:

I recently read an article concerning the breaking of the sound barrier in a German aviation magazine. According to the article the sound barrier was actually broken sometime in 1945 by an Me 262 pilot. The story goes that he was off on a test sortie when he was re-called to base asp. He was somewhere over Austria at the time at a pretty high altitude. He turned for home stuffing the nose down at full power when he started to experience pitching, buffeting and slight control reversal ( all things associated with trans sonic flight), when suddelly all everything went fairly quiet. The pilots at the time were forbidden to carry out any high speed flight at the time due to the precious lack of Me 262's at the time, so he kept quiet about it. The only thing that (after landing) let him down was the evident airframe buckling that had occured!
If any one is interested I could dig out the article and translate it for you.
There's a chap in the USA building one at the moment fitted with Lear jet engines as far as I remember, anyone know when it's due to fly?

Abso-bluddy-lutely fascinating Spiney, THANKS!

Indeed several Me262s are being built in Seattle, with the first example undergoing engine test in preparation for a first flight sometime in the very near future. They are powered by the commercial equivalent of the F-5's engine. (Could very well be a Learjet engine, but I'm not that familiar with Learjets)

For more info: Me262 project

That is some project!

History repeating itself. :cool:

CamelPilot:

I do not agree that level flight was a requirement (as you implied) to qualify as first through the sound barrier . Also your choice of the word " attempt" when referring to George Welsh's flight is not really a good one.
The level flight scenario is simply a reflection of speed whereas the barrier was something else ie a wall . What did it matter if the first man through was in level flight, nose down, or for that matter vertical. First through was First through and if George Welsh did it in a dive then the credit is his. I'm starting to form the opinion that it is not only the Japanese who distort history but others as well. Nothing personal my friend, just trying to tidy things up a bit.

Prince of Dzun

Hi Cyclic Rick.
Very Interesting info re the Me262. I must admit, I've never seen any good info on the subject of supersonic flight, either attempted, or by accident in the Me262! The period you mention is fascinating for me because so much new technology was available to pilots, particularly of the Luftwaffe, and yet official control of their exploits was so low that what you actually did with it was pretty much up to you! We'll never really know if an Me262 went supersonic, or the Miethe Flying disc actually flew but wouldn't you like to think so? I know I would.
Messerschmitt did actually build a prototype variant of the Me262 to test the airframe Mach limitations. This being V12 (Werk-Nr. 130 008, VI+AG). But unfortunately, the maximum speed officially recorded for this aircraft was 624 Mph. I'd guess that the stories about supersonic flight in the Me262 are probably inaccurate due to the many and varied problems associated with the Jumo 004 turbojet which was prone to catastrophic failure due to lack of suitable metallurgical research and manufacturing technique. And secondly due to a known fault where, at high speed, the fairing over the starter engine, known as the Zweibel, would detach, sealing the engine exhaust causing an immeadiate flame out and such violent yaw that the aircraft would break up! But, as with all these things...you never know!

Spiney

My reading of Yeager's book...and watching everything I have ever stumbled across on TV/DVD/Video on the subject leads me to believe,

1/. The US attempt at the sound barrier was conducted in a climb...so if things turned to poo they could slow down quickly.
2/. Even Bell Technical people were dumbfounded/relieved that the Miles M52 was abandoned...they believed it was good technology.
3/. Some 6 months after Yeagers 'official' first supersonic run a scale M52, radio controlled, exceeded the speed of sound.
4/. Lots of good evidence to suggest Welsh was the first man through...hushed up for political reasons...the second time that man was thoroughly screwed in his career...the other time being when the Army Air Corps downgraded his CMH to a lesser award because he was not 'authorised' to take off from Haliewa during the Pearl harbour Attack...he shot down 5 minimum that day...if the US AAC could be that childish under those circumstances I'm certain they could claim the SoS for themselves. Friends of mine who have been supersonic in F86s (Australian version) say it was effortless in a shallow dive and as smooth as silk...can't of been that much of an effort for Welsh.
5/. Watched an interview with an ex ME262 German test pilot from the Reichelin days who claims that SoS was impossible in M262. Way too much drag was his reason, coupled with unreliability.
6/. The drag from the propeller coupled with the way shock waves form on the thick straight wings of WW2 piston fighters means SoS impossible....a lot of VERY talented pilots killed exploring high speeds in Spits, Mustangs etc.
7/. My own father tried VERY hard in early Vampires, Meteors to see how fast he could make them go in the early 50s...full power straight down from above 30000'....and not even close!!:eek:


Chuck.

The sound barrier was actually broken by a New Zealander called Richard Pearse in 1946. I know this for a fact because I read it in a book. It was on a website as well. Several reliable witnesses, interviewed in the late 1990s, saw they saw him take off in an ingenious, homebuilt rocket plane, fly a complex aerobatic routine and then multiple sonic booms were heard over a radius of several hundred miles.

All this stuff you have heard about Chuck Yeager being first is simply rubbish. Yet another example of aviation history being re-written by the Americans, denying the credit to a brave and ingenious Kiwi...

Reading it in a book does NOT make it fact! Books are given to us to help us understand. We can only hope that what they say is truth.

Having said that. Richard Pearse was indeed a great aviator. He also claimed to have flown before the Wright brothers. Who do you believe? There is record of the Wright's. There is not one of Pearse's 'attempt.'

I quoted from a book written by one of the country's finest. Respected by all test pilots from the early 40's when he joined Hawker's to the day he died. Many of these were at his Memorial service in February of this year.

What you have to be sure of is "your" facts, because when it comes down to it there is precious few of them. And when you have "your" facts before you where did they come from - books most likely.

I have to say that I don't buy the theory that Welsh broke the sound barrier because there is nothing to back it up. Try finding reference to it on the internet. That there was a cover up is possible but there are no facts. There is plenty on Welsh but nothing about him breaking the s/b. In his own books he doesn't lay claim to it either. Just his efforts in American football, where he was a coach, and a very good one.

This is still a good thread but I would suggest that the pedantic use of knowledge gets us no-where - if you see what I mean. Just for the sake of correctness, the sound barrier is in fact a virtual wall, where the air is compressed until it will compress no more.

Chimbu chuckles.
You're spot on regarding the M52 models. I didn't mention them in my original post because I wanted to make the point that the written evidence appears to be that the project was scrapped due to the usual political ineptitude and interference . It would appear that in the final stage of model tests the M52 achieved M1.38 but, and here's the best bit, the model based programme cost ten times the projected cost of the manned aircraft programme! Some years after the M52 programme had been abandoned, (1955), A government white paper was published which stated 'the cancellation of the M52 seriously delayed the progress of aeronautical research in the U.K.' I don't think there is any doubt about this considering that the M52 was not just a simple vehicle designed to penetrate the sound barrier but a turbojet powered aircraft which would have given valuable evidence on transonic wing and intake design, plus useful info on re-heat development.

Spiney

Indeed there's no such thing as a sound 'barrier'. It's no wall.

What does exist is the transsonic region where airplanes not designed for the speeds in this region will experience many strange (to the untrained) phenomena such as mach tuck, compressibility issues, control reversal, buffetting, unreliable airspeed indications etc.

Now mind the last one there: unreliable airspeed indications! As the airplane is not designed for these speeds, the ASI won't be calibrated for it either! So any story about people flying WW2 era planes 'through the sound barrier' must be taken with a pinch of salt in my opinion. A pilot may well have experienced buffeting and strange readings that made him think that he exceeded the speed of sound, but he might still have been quite a bit slower than that, he was just getting close to the limiting mach number for that specific aircraft.

I seem to recall that when the Bell engineers examined the M-52, they realised that the M-52's all-flying tail would give them the control they needed for the Mach 1 attempt. Up to this point the X-1 had had a conventional fixed tailplane and elevators.

Puts on flak jacket and retreats to bunker......

Chcuk Yeager told me he was sick of the Brits forever whining to him about how the M.52's design had been stolen by the Yanks. He said that the all-flying tail was the particular thing that marked the X-1 out from the M.52 - he confirmed what LowNSlow says, that it was the crucial part of the Bell's supersonic success. However Yeager was adamant that this was an American not a British innovation. If the all-flying tail was indeed a feature of the M.52's design I would be very interested to learn more about it.

btw Yeager also told me that when he left Europe after WW2 he disliked the English more than he disliked the Germans... he is some character!

The brits had a all flying tail plane installed and working on a aircraft long before the M52 or the Bell x ,will track the article and photo down and post it.

PS. we have a tv prog here run by a guy called Jerremy Clarkson, he is doing a series on speed at the moment, allbeit a light hearted look.
He was talkin about this very thing in his program last week
He showed a clip of Chuck making that statement and immediatly after showed a clip of the early flying tail plane aircraft.

pps, there are dozens of articles on the web re M52, google lists many, here is a snippet I just found.

The M52 was to be the first supersonic aircraft in the world, but the Government-funded project was cancelled abruptly.
Mr Kite said: “It was assumed by Ben Lockspieser, the Minister of Aircraft Production, that it was too dangerous to risk pilots’ lives trying to get through the sound barrier.”
To add insult to injury MLA was ordered to hand its work and designs over to the American Bell Aircraft Company.
A year later Major Chuck Yeager, of the US Air Force made the world’s first supersonic flight in a Bell-X1

Back to the Me262 topic, some time ago I read accounts from several 262 pilots (can't remeber the source) attacking bomber formations from the considerable heights they started their attack runs. Some mentioned lots of turbulence as the speed increased, then smooth flying with the ASI off the clock having seen it kick just as the flight became smooth. Sounds like SoS to me, although they may not have known it at the time.

Me262 Supersonic?
 

I'm afraid I'll have to doubt that. The airflow over a part of the airframe or wings may have gone supersonic, or may have gotten close to it, which could account for some buffet, but not the whole plane. Had this happened the centre of lift would have shifted back and there wouldn't have been enough elevator authority to keep the nose up!

More likely they experienced some local compressibility effects, producing mild 'turbulence' and when they descended the increasing density made the local airflow go back to subsonic.

I don't think the basic Me262 design would be capable of going supersonic, definitively not with a normal elevator! But if anyone can produce some facts on this I'm always interested!

Did not our dithering politians of the mid/late forties give the Miles jet to the Americans( in return for some favour or something), who at that time were far away from total control at SOS speed, it was the discovery of the fully movable or flying rear wings that allowed the Bell company to go on and break the sound barrier and in typical form claimed it as their success only?
I seem to think that Aeroplane monthly did a run on this not long ago!
My regards
PeterR-B