Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: glock89 on November 17, 2008, 08:45:38 PM
-
Break the sound barrier? I have this magazine and show a model of a Me-262A1 and the pilot who Hans-Guido Mutke said to break the sound barrier with this plane? Dose any one know if this is true?
-
Ahh, the old Mutke story.
Short answer: No - the plane wasn't aerodynamically able to do that.
http://www.aerospaceweb.org/question/history/q0198c.shtml
-
Oh thank you for that when i saw that i was WTF :eek:.
-
I'd say that it is possible that Mutke did break the sound barrier but it is only a fluke that he was still alive to tell about it - as well it is possible that he didn't. Speed indication and loss of control do not mean that he did, however.
So to be a bit more specific there was probably nothing in the design of 262 that would prevent getting to Mach 1 in favourable conditions but aerodynamically it could not do that in controlled flight.
Nice article but it does not cover if the drag of the aircraft would prevent the a/c from reaching Mach 1, only that the instrumentation could not be trusted to give correct indication of speed and that control was not possible, both which are certainly true.
Anyway, Mutke was lucky to be in a plane that could hold together at those speeds and to have a fully movable elevator.
-C+
-
I have heard claims from 51 pilots that they did push the control surfaces through the barrier, i.e. loosing control and regaining at higher speed.
However that is the airspeed over the wing and/or tailplane, NOT the airspeed of the aircraft itself....
-
Isnt it quite possible that they were in the transonic region?
Even at speeds as low as .85 mach its possible to have Mach flow over some wings.
Race
-
Isnt it quite possible that they were in the transonic region?
Even at speeds as low as .85 mach its possible to have Mach flow over some wings.
Race
Of course it is. What do you think compressibility is? Local shock waves over the surface of the aircraft, typically the upper surface of the wing.
Edit: Sorry Race, didn't want that to sound like I was talking down to you. :salute Your comment is absolutely correct.
-
All WWII fighters could get into compressibility (some more controlled than others). However, local supersonic flow is not the same as supersonic flight. The aircraft itself is not flying faster than sound.
I have seen nothing that makes me believe the 262 cannot achieve Mach 1 in a dive, nor have I seen any credible evidence that it did. I've heard many say that the fuselage of the 262 is too think to allow supersonic flight, but that is bull. Some business jets have broken the sound barrier by accident, and the Boeing 727-31 TWA flight 841 which went supersonic in an accidental dive in 1979. On August 21, 1961 a Douglas DC-8 broke the sound barrier at Mach 1.012 in a controlled dive through 41,088 feet. So it is certainly possible that the 262 did so too.
-
What was the name of that American fighter that had to be redesigned because it couldn't reach Mach 1 despite being powered by a J57 engine of 17,000lb thrust? Oh yes, the F-102.
-
What was the name of that American fighter that had to be redesigned because it couldn't reach Mach 1 despite being powered by a J57 engine of 17,000lb thrust? Oh yes, the F-102.
Get your facts straight. The YF-102 flew supersonic in level flight but it was below the design goal. In a dive it would be able to reach Mach 1 with the engine idling. Even now a Frenchman is preparing to skydive supersonically by parachuting from a balloon with a special aerodynamic suit.
-
I dont think the engine of the 262 would like supersonic flight.
Subsonic jet engines work by compressing the air, igniting it, and that air if forces through a turbine on a shaft that runs back to the compressor. At these subsonic speeds, the air is forced faster through small spaces, much like putting your thumb over the end of a hose.
Supersonic jet engines work differently. At supersonic speeds, the air acts completely opposite of subsonic speeds. The air will actually slow down and pile up through a narrowed region instead of speeding up and forcing its way through. The air needs to be slowed down before reaching the compressor. Early jet engines did this by incorporating a point coming from the center of the compressor ahead of the engine inlet. As the air hit this point, it piled up on itself and slowed to a subsonic speed. This air was then put through the engine. New supersonic engines do not include a compressor, they simply narrow the inlet gradually. This narrowing compresses the air and then it is combusted.
From a jet engine standpoint the plane could not do it. Maybe in a dive, but the engines themselves would cause huge amounts of drag (air piling up). and would add no additional thrust.
I think it could probably hit the transonic range.
-
I have this magazine and show a model of a Me-262A1 and the pilot who Hans-Guido Mutke said to break the sound barrier with this plane?
No, the only thing that breaks the speed of sound around here is your ability to hit 'reply' and 'post', numerous times in succession.
-
I dont think the engine of the 262 would like supersonic flight.
Subsonic jet engines work by compressing the air, igniting it, and that air if forces through a turbine on a shaft that runs back to the compressor. At these subsonic speeds, the air is forced faster through small spaces, much like putting your thumb over the end of a hose.
Supersonic jet engines work differently. At supersonic speeds, the air acts completely opposite of subsonic speeds. The air will actually slow down and pile up through a narrowed region instead of speeding up and forcing its way through. The air needs to be slowed down before reaching the compressor. Early jet engines did this by incorporating a point coming from the center of the compressor ahead of the engine inlet. As the air hit this point, it piled up on itself and slowed to a subsonic speed. This air was then put through the engine. New supersonic engines do not include a compressor, they simply narrow the inlet gradually. This narrowing compresses the air and then it is combusted.
From a jet engine standpoint the plane could not do it. Maybe in a dive, but the engines themselves would cause huge amounts of drag (air piling up). and would add no additional thrust.
I think it could probably hit the transonic range.
Boeing reports that the Boeing 747 broke the sound barrier during certification tests. A China Airlines 747 almost certainly broke the sound barrier in an unplanned descent from 41 000 feet to 9500 feet after an in-flight upset on 19 February 1985.
(http://upload.wikimedia.org/wikipedia/commons/3/36/Jal.747.newcolours.arp.750pix.jpg)
If this thing can break the sound barrier in a dive...
-
Not really. A 747 has more sweep on its wings which will allow it a far higher critical mach number than a 262. Wing section is probably better too. Also it has an all flying tail, which will allow it better control in the transonic region.
-
Critical Mach and controllability is irrelevant. We are not talking about a controlled dive here. And the 262 did have a flying tail for trim (same as the 109). There is no reason why the 262 shouldn't be able to reach Mach 1 in a "suicide dive". Hell, even the Spitfire reached Mach 0.9 in a test dive, though the prop and reduction gear fell off and the wings were bent backwards.
(http://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Spitfire_XI_EN_409.jpg/180px-Spitfire_XI_EN_409.jpg)
-
Get your facts straight. The YF-102 flew supersonic in level flight but it was below the design goal. In a dive it would be able to reach Mach 1 with the engine idling.
The F-102 concept was later redesigned useing the "Area Rule Concept" in developing the F-106 DELTA DART aircraft which could easily do over Mach 2 with virtually the same engine.
(http://www.military.cz/usa/air/post_war/f106/f106deltadart.jpg)
:salute
-
Area ruling was incorporated in the YF-102A prototype which led to the production F-102A. The F-106 (originally named F-102B) had so many changes that is was essentially a new aircraft. Your "virtually the same engine" argument does not hold water either. The F-102A's J57 produced 17,000 lbs of thrust. The F-106's J75 produced 24,500 lbs of thrust.
How hard can it be to look these things up? Get your facts straight.
-
Not really. A 747 has more sweep on its wings which will allow it a far higher critical mach number than a 262. Wing section is probably better too. Also it has an all flying tail, which will allow it better control in the transonic region.
all flying tail meaning?
-
AFAIK the 262 was capable of transsonic flight, but was rarely ever able to recover from it due to structural failure as a consequence. If it actually ever broke the sound barrier is hard to tell (perhaps as it desintigrated), as we all know Germany lost the war and few 262 pilots lived to tell their tale. Even fewer experienced transsonic flight in the 262 and survived it, in fact, Mutke may be the only one.
-
all flying tail meaning?
I think they're referring to a trim system where instead of trim tabs on the elevators the whole horizontal tailplane shifts. IIRC the 109 had this as well.
-
Area ruling was incorporated in the YF-102A prototype which led to the production F-102A. The F-106 (originally named F-102B) had so many changes that is was essentially a new aircraft. Your "virtually the same engine" argument does not hold water either. The F-102A's J57 produced 17,000 lbs of thrust. The F-106's J75 produced 24,500 lbs of thrust.
How hard can it be to look these things up? Get your facts straight.
1. The YF-102 (NOT YF-102A - your original statement) DID NOT employ the area rule principle - one reason it was redesigned.
2. Agreed, so many changes were made to the design - it was changed to the F-106 - but alot of these were internal and to the radar and fire control system. Nothing of what the post was talking about about the aerodynamics of the aircraft or how it related to the ME-262 breaking the sound barrier.
3. If I am correct - the J57 is still a "J57" just a different version with more thrust so "essentually" it is the SAME engine isn't it? Virtually the same size and weight?
I would also suggest YOU might better spend your time looking up your facts and get off Wikipedi - while your at it you might want to see about learning some manners.
:salute
-
1. The YF-102 (NOT YF-102A - your original statement) DID NOT employ the area rule principle - one reason it was redesigned.
You said "The F-102 concept was later redesigned useing the "Area Rule Concept" in developing the F-106 DELTA DART...". That is wrong. Area ruling was incorporated in the F-102 design before the development of the F-106. The production model F-102A included area ruling.
3. If I am correct - the J57 is still a "J57"...
What?
-
It may be worth mentioning that the F-80 Shooting Star was unable to exceed Mach .96 under any circumstances, verified by NACA wind tunnel testing.
The chances that an Me 262 exceeded Mach 1 are nil. Even the F-86, a genuine transonic fighter, could barely exceed Mach 1 (Mach 1.09) in an extended dive from 35,000 feet.
My regards,
Widewing
-
It may be worth mentioning that the F-80 Shooting Star was unable to exceed Mach .96 under any circumstances, verified by NACA wind tunnel testing.
Well look at it...
(http://upload.wikimedia.org/wikipedia/en/thumb/2/2d/P80.600pix.jpg/300px-P80.600pix.jpg)
-
The 262 was aerodynamically superior to any other jet of it's era. Yes look at the P-80 and it's predecessor (P59??? don't recall the name of it but it looks like a porked pig on wheels when parked), look at the Meteor, no wonder the allies didn't consider the jet to be ready for front line use. They weren't fast enough to be considered worthwhile. (http://hem.bredband.net/turnik/icons/icon_doh.gif)
To compare the 262 with the P80 is like comparing the, well... Supermarine Spitfire MkI with the Hurricane MkI, they are that different. Aerodynamically and design philosophy, totally different but of the same time. (Actually that isn't true, the P80 is a later design, look at the P59 instead.) The angle of the swept wing of the 262 happened to be a very lucky configuration. The german engineers didn't know it when it was drawn (I don't know the particulars of it), but the test results of the a/c showed in black and white what a capable design it was.
-
Jets of the 1940's
USA - Bell P59 Airacomet
(http://upload.wikimedia.org/wikipedia/commons/thumb/5/5b/050324-F-1234P-004.jpg/300px-050324-F-1234P-004.jpg)
UK - Gloster Meteor
(http://www.oldtimerfan.nl/wp-content/galerij/gloster/meteor-f8/024dbdaabdb020423cccc415f716ee20_n.jpg)
Germany - Messerschmitt Me262
(http://www.raf.mod.uk/history_old/t_images/me262a1.jpg)
So tell us, which design would appear to be the most advanced?
-
(http://img145.imageshack.us/img145/1904/p80vsme2625mv.jpg)
Comparison testing at Wright Field showed that the P-80A was superior to the Me 262 in every performance category except dive acceleration. In a sustained dive, the 262 pulled away slightly initially. However, it entered full compressibility at Mach 0.84 and continued diving would result in the 262 nosing over through vertical and suffering a sudden catastrophic break-up. On the other hand, the P-80A pilot could simply pop his speed brake....
The YP-59s were testbeds... Never intended for combat. Also, the Meteor you show is a post-war F8 which outclassed the 262 by a considerable margin. The late-war (flying combat sorties before the surrender) F.MkIII was very much the equal of the 262.
My regards,
Widewing
-
Okay, there we have the answer, and I stand corrected. Does your sources tell the exact mach speed at which the 262 airframe would start to break up?
Also there are 262 replicas flying today, do you know how close to the original they are in performance?
:salute
-
Those replicas aren't even using the same engine or anything even resembling the original engine. It is a much smaller engine inside dual housings to make it appear like the original Jumo and it also has greater thrust than the original Jumo.
To draw conclusions or based on the replicas would be erroneous.
-
They should still be able to simulate fairly closely the original 262 by limiting use of thrust to what the original had, no? The airframe should also be identical or nearly identical, though they would be stupid to fly near the high-speed end of the envelope with replicas.
-
Big BLACKHAWK fan there Widewing? ;)
-
Comparison testing at Wright Field showed that the P-80A was superior to the Me 262 in every performance category except dive acceleration.
If so, then why was the Boyd report suppressed? The report had the 262 superior in speed and acceleration and equal in climb. The P-80 was better in handling and had better visibility.
Also, if you are to make comparisons with the P-80A, then compare it to the 262 which would have been using more powerful Jumo 004 engines.
............................. ............................
The replica 262s use J-85 engines with thrust pushing 3000lb. Because of the excess of power, they they have flight restriction so as to not over stress the airframe.
-
If so, then why was the Boyd report suppressed? The report had the 262 superior in speed and acceleration and equal in climb. The P-80 was better in handling and had better visibility.
Also, if you are to make comparisons with the P-80A, then compare it to the 262 which would have been using more powerful Jumo 004 engines.
............................. ............................
The replica 262s use J-85 engines with thrust pushing 3000lb. Because of the excess of power, they they have flight restriction so as to not over stress the airframe.
If I recall correctly, wasn't the early comparison test done with the surviving XP-80A (Silver Ghost)? I have heard about this report for years, but haven't found anyone who has actually seen it.
My regards,
Widewing
-
Inconvenient and/or counterproductive test results are often supressed by authorities in order to prevent that the general public and even concerned professionals get upset. Especially in times of war, such as WW2 or the "cold war". It's been done by all nations throughout history, in all aspects of society. I very much doubt the USofA to be a exception in that regard. :lol I'm not saying that it happened in this particular case, just saying that there's a official truth, and a inofficial and confidential truth. All nations, no exceptions.
-
(http://img145.imageshack.us/img145/1904/p80vsme2625mv.jpg)
Comparison testing at Wright Field showed that the P-80A was superior to the Me 262 in every performance category except dive acceleration. In a sustained dive, the 262 pulled away slightly initially. However, it entered full compressibility at Mach 0.84 and continued diving would result in the 262 nosing over through vertical and suffering a sudden catastrophic break-up. On the other hand, the P-80A pilot could simply pop his speed brake....
The YP-59s were testbeds... Never intended for combat. Also, the Meteor you show is a post-war F8 which outclassed the 262 by a considerable margin. The late-war (flying combat sorties before the surrender) F.MkIII was very much the equal of the 262.
My regards,
Widewing
Your image:
(http://img145.imageshack.us/img145/1904/p80vsme2625mv.jpg)
So the Me 262 was longer, had a greater wingspan, and grater weight than the P-80. The P-80's Allison J33 turbojet engine rated at 5,400 lbs of thrust, and the Me 262's two Junkers Jumo 004B-1 turbojets only managed a combined 3,960 lbs of thrust.
So the Me 262 was bigger, heavier and had only two thirds the power available, but still managed to be almost as fast as the P-80. What does that say for the relative aerodynamics of the two aircraft?
-
As for the Meteor III being the equal of the Me 262 I put great faith in the words of Eric Brown who flew both aircraft (and he told me this personally), I paraphrase: "In a fight between the Me 262 and the Meteor there would be no contest. The Meteor was a pedestrian aircraft by comparison."
-
So the Me 262 was longer, had a greater wingspan, and grater weight than the P-80. The P-80's Allison J33 turbojet engine rated at 5,400 lbs of thrust, and the Me 262's two Junkers Jumo 004B-1 turbojets only managed a combined 3,960 lbs of thrust.
So the Me 262 was bigger, heavier and had only two thirds the power available, but still managed to be almost as fast as the P-80. What does that say for the relative aerodynamics of the two aircraft?
This is incorrect. You are describing the J33-A-35 that was installed in the last 561 F-80C fighters, which didn't begin delivery until the fall of 1948.
The P-80A was powered by a J33-A-9 generating 3,850 lb of thrust.
Thus, the P-80A was notably faster on less thrust.....
My regards,
Widewing
-
Actually its interesting to look at the speed vs. altitude.
The 262 is slower on the deck that at 15000, then slows again at 33000.
The P-80 is fastest on the deck, and decreases in speed with altitude.
What I determine from this is that the P-80s speed is limited by thrust. It goes higher, less air density, less thrust, lower speeds. The 262 on the other hand is more limited by drag. On the deck the engines should be making the most thrust, but the drag of the plane slows it down. The ideal altitude is 15000ft were the density allows for good thrust and lower drag.
Conclusion, P-80 is the aerodynamically superior design.
-
Despite a difference in gross weight of nearly 2,000 lb (907 kg), the Me 262 was superior to the P-80 in acceleration, speed and approximately the same in climb performance. The Me 262 apparently has a higher critical Mach number, from a drag standpoint, than any current Army Air Force fighter.
World War II Fighting Jets
ISBN 1-55750-940-9
Jeffrey Ethell and Alfred Price
Motorbooks International, 1994
page 180
-
Was Eric Brown quoting the Meteor III or the I then?
-
Immediately after World War II, Kelly Johnson, the legendary Lockheed Skunkworks engineer, built a six-foot-wingspan, 600-pound, solid-steel model of thee Lockheed P-80A Shooting Star (later designated F-80) and had it dropped from a P-38 at altitudes close to 40,000 feet. “In a vertical dive,” he wrote in a letter to Fisher, “the model would not exceed a true airspeed of higher than Mach .94. With the full scale model of the Lockheed F-80A, these results were confirmed, and there was no recorded case where this jet fighter, clean as it was, could ever exceed Mach .9.”
http://www.airspacemag.com/history-of-flight/Mach_1.html?c=y&page=9 (http://www.airspacemag.com/history-of-flight/Mach_1.html?c=y&page=9)
Personally I doubt the two big Jumo pods of the 262 let it go any faster.
-
http://www.airspacemag.com/history-of-flight/Mach_1.html?c=y&page=9 (http://www.airspacemag.com/history-of-flight/Mach_1.html?c=y&page=9)
Personally I doubt the two big Jumo pods of the 262 let it go any faster.
This is a good article and the next page goes into detail about Herb Fisher. I know Herb's son (Herb jr.) and have a large collection of Herb's data and photos. Some of these are published on my website at: http://home.att.net/~historyzone/Fisher.html (http://home.att.net/~historyzone/Fisher.html)
For more info on who, in all probability was the first man to exceed Mach 1 (certainly in controlled flight), you can read about it here, http://www.airspacemag.com/history-of-flight/mach.html (http://www.airspacemag.com/history-of-flight/mach.html) and on my site, here: http://home.att.net/~historyzone/Welch2.html (http://home.att.net/~historyzone/Welch2.html)
My regards,
Widewing
-
World War II Fighting Jets
ISBN 1-55750-940-9
Jeffrey Ethell and Alfred Price
Motorbooks International, 1994
page 180
Again, I am aware of the this. However, no one has yet to produce the original test document. The only P-80 that I am aware of that was ever tested head to head with a captured Me 262 was S/N 83022, which was the second XP-80A.
My regards,
Widewing
-
Was Eric Brown quoting the Meteor III or the I then?
The Meteor in general. He flew them all and the 262 so I guess he's the authoritative test pilot source on these early jets.
-
Interestingly the Me 262 "survived" the war. 12 were made post-war by Avia in Czechoslovakia and flew into the 1950's.
-
The Meteor in general. He flew them all and the 262 so I guess he's the authoritative test pilot source on these early jets.
Then the question remains, for shortly after the war the meteor was the fastest of the lot.
262 had one quirk though which could be fixed, - no regulator. So throttling up and down was very delicate. But on full power and going that is not an issue.
-
WW great website. I've book marked it! The thing that is most often missed that amazes me is the courage the early jet pioneers and everyone that did mach busting testing had to do their job.
-
Then the question remains, for shortly after the war the meteor was the fastest of the lot.
Well, that's not really a fair comparison given the rapid advancement of engine development at that time. If the war had dragged on with a functioning German industry the 262 would also have had more powerful engines at that time. The 262 is really a spring/summer 1944 aircraft and changed very little performance wise throughout the war.
-
Well, that's not really a fair comparison given the rapid advancement of engine development at that time. If the war had dragged on with a functioning German industry the 262 would also have had more powerful engines at that time. The 262 is really a spring/summer 1944 aircraft and changed very little performance wise throughout the war.
Agreed with that one.
-
Well, that's not really a fair comparison given the rapid advancement of engine development at that time. If the war had dragged on with a functioning German industry the 262 would also have had more powerful engines at that time. The 262 is really a spring/summer 1944 aircraft and changed very little performance wise throughout the war.
The 262 probably wouldn't. The engines at the power they had, did incredibly short service time and were quite unreliable.The reason was that the design exceeded the available material.Germany in shortage.
However, it would have been interesting to see a 262 powered with the post war Meteor engines;)
Bear in mind though that they were a different design, and the concept is no longer in use...
-
IIRC Adolph Galland, who flew Meteors post war in South America, said his ideal jet of the time would have been a 262 with Rolls Royce engines.
-
The 262 probably wouldn't. The engines at the power they had, did incredibly short service time and were quite unreliable.The reason was that the design exceeded the available material.Germany in shortage.
However, it would have been interesting to see a 262 powered with the post war Meteor engines;)
Bear in mind though that they were a different design, and the concept is no longer in use...
Yes it was a production quality issue, not a design issue. Let's put it like this: If the British or US had copied the 262 design after VE day in 1945 (a one year old plane at that time) and built it using proper materials and in proper production facilities (as opposed to in a forest clearing somewhere in Germany), this "allied 262" would have been far, far superior to the British and US designs at that time.
Fact is that many 262's were made from scrap in the bush using hand tools, and still they were more than a match for the best the allies could make.