Which jet was better, the Me 262 or the Gloster Meteor? (1 Viewer)

[Magnon]

LETTER TO OWNERS/OPERATORS NO 2420
ROLLS-ROYCE DERWENT MK 8 AND MK 9 ENGINES FITTED TO GLOSTER METEOR AIRCRAFT
ENGINE CRITICAL PARTS CYCLIC LIFE

Ref http://www.caa.co.uk/docs/1594/LTO2420.pdf

"...Derwent engines do not have formally defined critical parts as modern engines would. Those parts that are considered to be critical are the impeller, the turbine disc and the turbine shaft. It is known nowadays that failure of these parts is caused by metal fatigue, which is driven by cyclic usage. A failure of these parts could lead to uncontained engine debris with high release energy. There was no cyclic life control applied to these critical parts as the inspection of these components for evidence of cracks were carried out frequently at overhaul or during hot end change. Thus, the inspection interval for these critical parts would have been up to 450 hours for the turbine disc and up to 900 hours for the impeller and shaft sections, the number of cycles accumulated would have been very small..."

OK. I know this proves nothing as to the early (ie WW II TBO figures, but it gives some indication).

 

[Magnon]

From Me-262: Wunderplane or compromise?

After the war, "Watson's Whizzers," led by Colonel Harold E. Watson from USAAF Air Technical Intelligence, shipped several intact Me 262s to the United States for further evaluation. The tests, conducted by Albert Boyd (the head of flight test for the USAAF) and a soon-to-be-legendary Chuck Yeager, determined that the performance of the Me 262 was essentially equal to the P-80A. The Me 262 had a slightly higher critical Mach number-0.83 Mach versus the handbook limit of 0.80 Mach for the P-80A--but the difference was of little value in the real world since the Me 262 could only reach that velocity in a dive, whereas the P-80A could do it in level flight. However, despite the fact that the Me 262 was almost 2,000 pounds heavier than the P-80A, the German aircraft accelerated quicker and had approximately the same climb performance.
[That would have been acceleration with the nimonic hot end components... a big difference to the wartime Me 262]

During the tests it was found that the slightly swept wing of the Me 262 provided no useful reduction in drag, mainly because the triangular cross-section of the fuselage created so much base drag that nothing could really help much. The swept wing did not change the critical Mach number by a measurable amount, and certainly did not help performance in the low transonic region where the Me 262 was particularly unstable. The P-80A had much better handling characteristics than the Me 262, largely because it was more refined aerodynamically and had its thrust vector on the centerline of the aircraft instead of at the quarter-span of each wing.

Summary

Was the Me 262 a Wunderplane? As always, it depends on the situation. The Me 262 was clearly the best interceptor used during the war. It was extremely fast by the standards of the day, was equipped with a powerful set of cannon, and had the ability to carry rockets as supplemental weapons. The radar-equipped versions added versatility to the mix.

As a tactical fighter, the Me 262 was not nearly as successful. It had relatively poor maneuverability, and the heavy cannon armament was not particularly effective against maneuvering fighters or ground targets. The jet engines spooled up slowly, severely limiting acceleration, placing a premium on the emerging concept of energy management. As an escort fighter, as with all early jets, the Me 262 was hopeless because of its short operating range.

Nevertheless, the Me 262 had excellent performance compared of other early jet fighters. It was clearly superior to the Meteor Mk I, its closest contemporary, and was essentially equal to the later Meteor Mk III. It is possible that at certain altitudes the Me 262 could out-climb a Meteor, albeit only by a slight margin. The most telling difference was the reliability of the British engines and their relatively benign response to throttle movements.

 

[Magnon]

...Another limitation of the F4 that I recall was a totally inadequate compass system that collapsed when any aerobatic manoeuvre was performed, quite a disadvantage in an aircraft designed as a day fighter. Again this was rectified on later marks of Meteor with the introduction of the G4B compass, an instrument that has seldom been surpassed, in my opinion, for accuracy and reliability. The engines of course being Rolls Royce were magnificent, you could literally throw a brick into the intake and the Derwent would spit it out the back end in small pieces with just the faintest of nicks on the centrifugal compressor and turbine blades. It had very few moving parts and in all my hours on Meteors I only had one engine failure, and that successfully relit at the first attempt.

The Meteor's handling qualities were truly excellent; it was the most forgiving of aeroplanes and was a joy to fly. It performed quite happily at Mach 0.74 with only marked control stiffening causing any great problems above that speed. A favourite trick in the Meteor was to point it straight up until the airspeed indicator read zero, then leave everything to see what happened. Usually the aircraft would simply fall into a vertical dive back towards mother earth and sort itself out quite happily. Only the Meteor's single engine performance was perhaps questionable, the engines were, of course, mounted on the wings, heaven knows why as they could just as easily have been positioned against the fuselage. The result was that at low speeds and high power, the rudder was only just man enough for the job; later marks of Meteor, with the straight fin and rudder, improved the asymmetric handling. The approach was flown at 110 knots and was straightforward with the view over the nose being completely uninterrupted. This took a while to get used to as the absence of a nice fat engine cowling was initially disconcerting, resulting in a feeling of sitting out in a void...
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...The approach was made at 125 – 130 mph with flaps and air brakes down. Full lateral and fore-and-aft control was maintained right down to stall at about 105 mph...
Aircraft Profile 078 - Gloster Meteor F IV

 

[Glider]

And the point is?

 

[Rocketeer]

How amusing are the poll results!!! Like all these polls, it is difficult not to be subjective....the Me262 is 'prettier', however, as we all know, that is never the full answer. The basic engine design (axial flow) of the Me262 was better than the centrifugal compressor of the Meteor, but material engineering was not as advanced to make best use of it (witness the very low MTBFs and MTBSs).
The ultimate measure is longevity.....Meteors are still working for a living (and have been since inception)...i.e the Chalgrove Ejection seat test beds and recently retired drones. Me262s (apart from a few licence built post war aircraft) died with the 3rd reich. The new builds use modern axial flow engines...so do you STILL stand by the Me262?!!!!!

 

[DerAdlerIstGelandet]

The ultimate measure is longevity.....Meteors are still working for a living (and have been since inception)...i.e the Chalgrove Ejection seat test beds and recently retired drones. Me262s (apart from a few licence built post war aircraft) died with the 3rd reich. The new builds use modern axial flow engines...so do you STILL stand by the Me262?!!!!!

No that is not the ultimate measure. It is not the fault of the Me 262 production ended when the 3rd Reich died. The Me 262 would have evolved and had a much longer service life. You can't give points to an aircraft that was able to be further developed because it was on the winning side.

 

[Magnon]

And the point is?

Lower approach speed... all things being equal, better soft field performance. But it wasn't equal; the Me 262 was often overloaded with subsequent undercarriage failure in landing on concrete strips.

Also, I neglected to say that the quoted speeds were for the F IV, which had a shorter wing than the F III. Again all things being equal, the latter F IIIs would have had lower corresponding speeds.

 

[Magnon]

No that is not the ultimate measure. It is not the fault of the Me 262 production ended when the 3rd Reich died. The Me 262 would have evolved and had a much longer service life. You can't give points to an aircraft that was able to be further developed because it was on the winning side.

That's not entirely true. Ten were constructed in Czechoslovakia after the war. See:
Warbird Alley: Messerschmitt Me 262

"Using equipment and components manufactured during the occupation of Czechoslovakia, some Me 262s were produced by Avia, in Czechoslovakia after the war, under the designation S.92."

The bottom line is that despite all their manufacturing capability and access to German tooling, the Czechs only built ten. It was a dead end as an individual aircraft because its engines were dreadful and the airframe was badly designed. The proposed Jumo 109-004H engine only had a thrust to weight ratio of 1.5:1 as against 2.8:1 for the Derwent V. The Jumo weighed 1.2 tonnes as against 568 kg for the Derwent V. That's a big handicap to overcome. The new German jets in the pipeline weren't going to be the answer to their problems.

On the other hand, as a concept, it had some features that were to be influential in the immediate post war years.

 

[DerAdlerIstGelandet]

That's not entirely true. Ten were constructed in Czechoslovakia after the war. See:
Warbird Alley: Messerschmitt Me 262

"Using equipment and components manufactured during the occupation of Czechoslovakia, some Me 262s were produced by Avia, in Czechoslovakia after the war, under the designation S.92."

The bottom line is that despite all their manufacturing capability and access to German tooling, the Czechs only built ten. It was a dead end as an individual aircraft because its engines were dreadful and the airframe was badly designed. The proposed Jumo 109-004H engine only had a thrust to weight ratio of 1.5:1 as against 2.8:1 for the Derwent V. The Jumo weighed 1.2 tonnes as against 568 kg for the Derwent V. That's a big handicap to overcome. The new German jets in the pipeline weren't going to be the answer to their problems.

On the other hand, as a concept, it had some features that were to be influential in the immediate post war years.

The point is the war ended in 1945. We can only speculate what would happen post 1945. Therefore post war longevity is not a factor.

 

[Magnon]

The point is the war ended in 1945. We can only speculate what would happen post 1945. Therefore post war longevity is not a factor.

OK. But longevity and general reliability during the war is a VERY big factor. That's more than enough in its own right to damn the Schwalbe as a fighter.

 

[Glider]

Lower approach speed... all things being equal, better soft field performance. But it wasn't equal; the Me 262 was often overloaded with subsequent undercarriage failure in landing on concrete strips.

Also, I neglected to say that the quoted speeds were for the F IV, which had a shorter wing than the F III. Again all things being equal, the latter F IIIs would have had lower corresponding speeds.

I thought that might be the case but you were quoting the Mk IV post war version, I think you will find this interesting


http://www.wwiiaircraftperformance.org/meteor/Meteor-CFE.pdf

Para 54 gives the structural limitation of 500mph.

Para 65 gives the Approach spead of 150mph, last turn in at 140mph and a touch down of 115 mph.

Para 73 covers the heaviness of the Ailerons making even moderate turns tiring

Para 76 the lack of stability in bad weather

Para 115 covers the impact of directional snaking on accuracy.

Apendix D covers surging and how this happens if the throttle is opened or closed too quickly.

The second part of your comment re the overloading of the Me262 on landing and failures. We did cover this earlier and I asked if you could find any references to this actually happening. Without that the comment doesn't stand.
I do not claim to be an expert on the problems with the Me 262 but failure on landing isn't one of the ones that I can remember reading about and you certainly could be correct, all I ask is that you support that statement with examples that happened during the war.

A similar situation exists with your statement about soft field performance. You have mentioned this before and all I have asked is that you support this with examples of any first generation jet operating from soft fields. I don't believe they did operate without tarmac and cannot find an example. Again you could well be correct and all I am asking you to do is to support your statement, without support the statement doesn't stand.

Its worth remembering that peacetime rules and standards do not apply during war time, let alone modern standards. An example one that supports this comment is the P51D. If you look at the wartime pilots notes for the P51D the dive speed is red lined at 505mph, look at the pilots notes printed after the war and the red line dive speed is 450mph.

 

[DerAdlerIstGelandet]

That's more than enough in its own right to damn the Schwalbe as a fighter.

If you say so...

 

[Shortround6]

...... The basic engine design (axial flow) of the Me262 was better than the centrifugal compressor of the Meteor, but material engineering was not as advanced to make best use of it (witness the very low MTBFs and MTBSs).

Something to remember is that while the basic IDEA of the engine design (axial flow) was better it took several more years for it to show much advantage in practice, and, no, it wasn't just due to material engineering.
It took several years for axial compressor design to equal centrifugal design on a pressure ratio basis and several more for axial compressors to equal or surpass centrifugal designs on an airflow to weight ratio and for pressure ratio. The Axial compressor did wind up exceeding the centrifugal compressor on both counts and sometimes by a very hefty margin but that was not the case in 1944-45-46.

 

[Magnon]

Thanks for the Meteor source, Glider. Networking like this is what we should be all about.

There are so many points here I am going to have to address them one by one.

Quote: I do not claim to be an expert on the problems with the Me 262 but failure on landing isn't one of the ones that I can remember reading about and you certainly could be correct, all I ask is that you support that statement with examples that happened during the war.
Glider

Well, I think when we have:
1. The ME262 Handbook indicating the machine exceeded its permissible landing weight when it had a full fuel tank - "In case of a very short flight in which fuel has not all been used from the auxiliary tanks, use caution in landing as the allowable landing weight is exceeded due to fuel load..."
Me 262 A1 Pilots Handbook
2. We have also - "...The landing gear was also suspect, and many 262s were destroyed or damaged due to landing gear failure."
Me262 - Aircraft Profile - Messerschmitt : Me262
3. From Me 262 Pilot Debriefing: A "Preliminary Flight Permission" (Vorlaeufige Fluggen Schimung) brought along by this pilot states that the maximum weight for starting is 7100 kg. This includes the basic weight of the aircraft, 3870 kg plus 3230 kg allowance for fuel and bombs. If the weight when landing was more than 5700 kg, special caution must be taken.
4. And feedback from the Me 262 Project: "As the landing gear was known to be another weak area on the original Me 262, a detailed analysis of landing gear stresses was directed. This process revealed that a shock loading was generated by the spin-up forces of the large, heavy main wheels, which had to be reacted into by the wing landing gear attachment structure. This placed a severe demand upon wing spar area and the airframe simply had to absorb these forces. Over time, this would have had a devastating effect upon the aircraft."
"In part, this problem can be traced to the history of the aircraft. As originally designed, the Me 262 was equipped with a standard tail wheel (in lieu of the nose wheel)."
"In the tail-dragger configuration, the main gear was bolted directly onto the wing spar; however, the tricycle modification resulted in the creation of a separate wing torque box to be used as a mounting point. This torque box was susceptible to damage, and very difficult to repair."
"On the new Me 262s, this area has been reinforced with additional structural features, and the project is considering additional design changes that may further enhance the safety and longevity of the landing gear. In addition to the wing box reinforcement, the nose gear mounting point and strut assemblies have been greatly improved. In short, the entire system has been strengthened by a significant margin above what it was originally."
These guys would have access to pretty much state of the art CAD stress analysis software. They are not anti the Me 262. They are also trying to build some replicas, which indicates that they have some positive regard for it surely? Or at least they did when they started out.

I think that a reasonably objective person would find this adequate evidence. If you don't, well that's fine, but then we will just have to agree to disagree.

 

[Magnon]

Something to remember is that while the basic IDEA of the engine design (axial flow) was better it took several more years for it to show much advantage in practice, and, no, it wasn't just due to material engineering.
It took several years for axial compressor design to equal centrifugal design on a pressure ratio basis and several more for axial compressors to equal or surpass centrifugal designs on an airflow to weight ratio and for pressure ratio. The Axial compressor did wind up exceeding the centrifugal compressor on both counts and sometimes by a very hefty margin but that was not the case in 1944-45-46.

The other thing is that Britain was running two jet development strategies in parallel. Both axial and centrifugal compressor based systems were being developed in competition with each other. If one failed, the other might work. It was the right strategy, proven by the superiority of overall performance of the centrifugal in the short term, which pragmatically was all that counted.

In fact, some in Germany realised the shortcomings of the axial. They had a hybrid centrifugal/axial under development. See Origins of German jet power . And also:
Helmut Schelp:
"Schelp also used his influence to force Heinkel to develop one of his pet projects, the "diagonal compressor", a sort of combination of the centrifugal and axial designs. At the time the pure axial compressors were having problems with surging and air intake turbulence, while the centrifugal designs proved fairly immune to these problems. Although it was mechanically possible to arrange a centrifugal stage in front of axial ones, this arrangement would require a large frontal area, and a small frontal area was the only real reason to use an axial arrangement. Schelp's diagonal stage appeared to offer the best of both worlds, only slightly larger than an axial stage of the same air flow, but with much wider-chord blades that should be more resistant to airflow problems. Schelp demanded that the HeS 011 use this design, which proved to be much more difficult to build than originally thought, and led to lengthy delays in that project.
After the war, Schelp was taken to London where he was on 24-hour call if anyone in the Air Ministry wanted to talk to him. This was rarely done, and Schelp found himself able to wander London at will. On one such trip he came across the Gloster E.28/39, bearing a plaque that stated it was the first turbojet powered aircraft to fly. It had actually been beaten into the air by over a year by the Heinkel He 178, and when Schelp pointed this out it was wryly suggested there may be some inaccuracy with the plaque. The correct lineage now appears on the E.28 display at the Science Museum."

I have seen reports that Rolls Royce were having minor trouble with surge on a design as late as the Conway, which with the Avon, was in the first generation of their axials. Design to minimize surge has only been mastered now with the advent of powerful computational fluid dynamics (CFD), which was out of the question in the 1940s.

 

[dennis420b]

I went with the 262, but I never was happy with the armament. the 4, 30mm mk 108 cannons are great for destroying bombers, but if the war would have gone on longer, and dog fighting between jets had become common, then high velocity 20mm's would have been needed, something the Meteor already had.

 

[johnbr]

The Mauser 213c 20mm had a velocity of 1200 m/s with rate of fire of 1200.

 

[Magnon]

The Mauser 213c 20mm had a velocity of 1200 m/s with rate of fire of 1200.

A very good weapon but it was never put into service.

 

[dennis420b]

The Mauser 213c 20mm had a velocity of 1200 m/s with rate of fire of 1200.

That would be perfect for dog fighting the Meteor, but not the Mk 108's is the point I was making.

 

[Magnon]

That would be perfect for dog fighting the Meteor, but not the Mk 108's is the point I was making.

Absolutely... I have argued that we are not really comparing two fighters here. The Me 262 was actually a specialist bomber destroyer. The low velocity 30 mm weapons were adequate for that role only.