Mistakes in Aviation

[FLYBOYJ]

BTW a "simple" fuel control from a helicopter turbine engine.

[kool kitty89]

On the materials for German engines issue I pretty much agree, but even without them the engines were producing much more than the initial design thrust (004D with 930 kp normal and up to 1050 kp thrust overrev w/out AB at 10,000 rpm and TBO of over 60 hr, and 1000 kp normal for the 004E 1,200 kp AB) with improvements. (and the 003E's annular combustion chamber had a life of over 300 hr in testing, made largely of mild steel!)

The transition to nonstrategic materials didn't so much limit performance, it just delayed development of the engines.

I do think that things would have gone better if development of the 001 (HeS-8 ) 006 (HeS-30), 004, and 003 had been focused on and any larger (and more problematic) designs left on the drawing board.

In particular the HeS-30 (006) would have been excellent on the 262, power levels equal or greater than the 004m at half the weight and at ~24 in diameter roughly 1/2 the frontal area. (in addition to being much shorter) And with much lower fuel consumption. (using a reaction type 5-stage axial compressor, achieving similar performance to the jumo's 8-stage impulse bladed compressor at a high efficiency) And much better operating characteristics and engine life.

Range, speed, climb, roll rate, turning ability, and spool-up performance all increased dramatically. (and weight reduced to ~12,500 lbs with full internal load, compared to 14,100 lbs)


And as to the need of more powerful engines for the larger single engined fighters like the P.1101 (or improving the He 162) even without the class II engine designs (HeS 011A rated for 1,300 kp, while weighting roughly 900 kg) developments of the 004 and 003 were sufficient (not to mention possibilities for the 006) with the 004E producing 1,200 kp with afterburner (possibly more with overrev to 10,000 rpm) weighing roughly 700 kg and the smaller 003D (redesigned reaction type compressor) producing 1,200 kp dry weighing only ~550 kg.

[red admiral]

You wrote the Meteor was a good a/c, and I just forwarded that IMO the Meteor of 44, 45 wasn’t a good a/c, but started to develop into such in the 50th.

The Meteor I, II and III were all prototypes rather than actual fighters with the Meteor IIIs being rushed into service to shoot down V-1s because they were fast at low level. The Meteor IV from the middle of 1945 was the first real fighter version with a considerable excess in performance over the Me 262. The Mach limit with the longer nacelles was increased to M0.81 before control problems started to occur. Speed and rate of climb massively jump up to better the Me 262's figures.

Most of the new jet aeroplanes in the pipeline for the Luftwaffe were only likely to "work" in 1946-47 and even then, there are considerable flaws with the designs most likely to be produced. Take the Ta 183 for example, which was produced in Argentina post war by FMA as the Pulqui with a massively more powerful and reliable engine. It was still a dog to fly. Most of the Luft 46 designs pin their hopes on the HeS 011 which never came close to making it's designed thrust in postwar development.

[Kruska]

Hello red admiral,

I don’t quite agree to your posting.

The first F 4 prototype flew on 17 May 1945, and went into production in 1947. So it wouldn’t be a fitting match for the 1944/45 Me262.

Also the comparison to a Pulqui doesn’t fit since Argentina had no previous a/c industry to back such a project. However the FW team in majority was taken into Russian “hospitality”, so that the MiG15 for sure incorporated a major share of these engineers knowhow.
The wing design is an absolute match to the previous FW design plans. From what I read the Meteor F4 and the later Korean versions FR9 or NF11 was no match for a MiG15.

In most publications referring to the Meteor, it shows that despite a vast range of mission roles and models, the Meteors mostly were used in the Ground Attack role, due to non satisfying performance as a fighter.

But my main point of view would be the fact that the Me262 could never proof or show its true potential due to non existing – extremely limited – metals/alloys and a totally out powered industry. Other forum members are far more knowledgeable then me in regards to the engine/turbine design of the German jets, but for what I conclude the problem was the usage of inferior materials – not the jet design itself.

Regards
Kruska

[red admiral]

The first F 4 prototype flew on 17 May 1945, and went into production in 1947. So it wouldn’t be a fitting match for the 1944/45 Me262.

There was no rush to produce the F.4 postwar, in any scenario where war rolls on then they start on the production line in late 45 but probably without the clipped wings.

The design team on the Pulqui II was lead by Kurt Tank and most of the FW design team in Argentina. The MiG-15 had absolutely minimal input from German designs, this myth being debunked back in the 80s. The argument of "it looks the same" i.e. it is single engined and has a swept wing is fairly ridiculous compared to the hard data showing its evolution from earlier Soviet projects such as the MiG-9.

The Meteor was used mostly for ground attack as by Korea it was outmatched by the 2nd generation of jet fighters. It became a two-seat night fighter instead given the lack new design for this requirement (eventually Sea Vixen and Javelin)

The problem with the German jets was the design itself (especially the 004) rather than any materials problems. The materials limit turbine entry temperature, which the Germans got around mostly from air cooled blades. The TETs of the Allied jets were only about 50K higher at most giving very slight advantages in specific thrust and fuel consumption (around 5%). With the Jumo 004, the German designers managed to design a jet that offered similar thrust to the Whittle designs, fuel consumption about 50% worse, chronic unreliability from surge problems with the axial compressor, and that weighed twice as much. Most of the problems came from the axial compressor, which weighed loads, had a very low pressure ratio, poor reliability (mostly surge from quick throttle movements) and had poorer efficiency than the supposedly inferior centrifugal compressors.

[Glider]

I think its worth remebering that the later Meteor III had the changes to the Nacells which significantly improved the speed of the aircraft making it a match in speed at least to the 262.
Also had the war continued I am confident the Mk IV would have been in production well before 1947. The basic design was very similar and no real difficulties would have been expected.

There is no doubt that the lack of suitable raw materials hindered the production of reliable engines for the 262 or any other German jet.

[Kruska]

Hello red admiral,

Unfortunately I do not have my Kurt Tank book with me, but I do recall the figure of about 1300 scientists, researchers, engineers and skilled workman from FW were entertained by the Russians, compared to about 25 in Argentina.

I also do not think that it has much to do with just copying existing German features (maybe to a small fraction) but having the extensive research protocols and evaluations of those features by a/c manufacturers which in turn had a significant impact on the timeline of the future development of a/c in any of the allied countries for the period of 10-15 years after the war.

E.g. variable geometry wing design wasn’t even dreamt about in any country besides Germany before 1944. That the US managed to modify and improve on it is understood since Germany didn’t exist for the next 4 years and had to rebuild its ruins for another 10 years.

So indeed I could forward that the F-111 is based on the experience and data collected through a XF-10F and Bell X-5 via a Me P1101. After all Bell had 6 years time to improve the Me P1101 developing an in-flight "variable-geometry" platform.


Regards
Kruska

[KrazyKraut]

Pfft, by the time the F.4 had been with combat units (late '45 at earliest), one of the HG versions of the 262 would've been ready. Even without improved engines it would've been a match and with newer versions of either jumo 004 or bmw 003 who knows how capable it would've been. The airframe was competetive until the late 40s at least and it's not like airframe development would've stopped.

BMW 003s were not only used in the MiG-9 but also were also developed into the Atar, which still powers the aircraft of several airforces to this day, so yeah there was tremendous potential. The Meteor was simply inferior.

[red admiral]

Going from P.1101 that didn't really have variable sweep wings, 10° change in angle and even then only on the ground, to the F-111 is a huge step and neglects the fact that the F-111 didn't really work very well. Another advocate of variable sweep wings was Barnes Wallis postwar with Wild Goose and Swallow projects. These were extremely advanced using only the wings as control surfaces with no tail or ailerons. The model built worked reasonably well on test flights before being cancelled from finanicial issues. Even so, variable geometry wings for such a small aircraft are a bad idea. Something slighter larger than the Tornado is the break-even point (the Tornado needing VG for landing restrictions)

one of the HG versions of the 262 would've been ready.

The HG II and HG III performance projections are completely ridiculous, especially for the HG III. Those performances weren't achieved for another decade and even then with hugely more powerful engines and a lot less drag from research in between.

The Atar is not the BMW 003 (which was a pretty good early axial engine actually. Probably second best behind the Metrovick series of the early efforts). Theres a large step between being the same and having the same arrangement.

The Meteor was simply inferior.

The I, II and III series of prototypes yes. The first acutal fighter version, the F.4 was superior to the Me 262 except in the rolling plane.

[KrazyKraut]

So you want to seriously tell me the Atar 101 isn't a direct evolution of the 003 and essentially a scaled up version of the latter? Despite being developed by pretty much the same team of German engineers? Do you know what the R in ATAR stands for? I assume the CETME is also not a descendent of the Stg-45 then?

And the projections for the HG didn't even have to be remotely true to be competitive or superior to the F.4, especially not with a new iteration of the 004 or 003. Given the pace of evolution of aircraft and (jet) engines at the time, to think that by late '45 there would not have been a second generation of 262s (which was only in the infancy of its lifecycle) available, especially with the evidence of its progress readily available, is just kidding oneself. And late '45 is a very optimistic guess for first operational use of the F.4, too, considering the maiden flight of may that year.

The airframe of the 262 was more progressive than that of the Meteor and the underwing engines, while aerodynamically inferior, made adaption to new engines pretty easy.

[kool kitty89]

Admiral the Mk.I was the Meteor to fight V-1's (albeit somewhat unsuccessfully due to the jamming problems with the cannon)

The Mk. III was the one to go on strafing missions over Germany in the last weeks of the war. (note, initially with short nacelles only ~20-30 mph faster than the Mk I, with long nacelles it did ~520 mph with Derwnt I's)


And the advantage of the 004's axial compressor was to reduce frontal area and improve aerodynamic efficiency, not fuel efficiency. Granted it was a conservative design (kind of a conservatively advanced design) intended to reach production in the shortest possible time, however problems with switching to non-strategic materials delayed production by ~2 years. (due mostly to the vibration problems along with some development time for air cooling, not solved until the 004D, which could overrev to 10,000 rpm and produce 1050 kp alo with TBO increasing to ~60 hr)

The air cooling developments were certainly an advanced feature though. And SFC was only ~20-30% worse for the 004B-4 than the Welland or Derwent I.

The 003 was a considerably better design though (the annular combustor, made largely of mild steel, lasting over 300 hr in testing) much more compact and lighter than the 004, though heavier than the Whittle engines, and more fuel efficient than the 004. The 003E producing ~920 kp with overrev, and a redesigned 003D (featuring a reaction compressor) producing 1,200 kp with little increase in weight or fuel consumption. (and thus specific fuel consumption went way down)


And there's the HeS-30 which cancelled in possibly the worst mistake in German jet development in the war. Weighing about the same as the Welland and producing up to 910 kp in testing, it utilized the more efficient reaction type compressor (opposed to the impulse blading of the 004) and produced about the same compression ratio in its 5 stage compressor that the 004 did in its 8 stage one, with 10 can-type combustion chambers, and a diameter of ~24 in, and excellent specific fuel consumption. (overall performance compared to weight, frontal diameter, and fuel consumption not exceeded until the J34 or MetroVick F.2/4 of the late very end of the 1940's)

The only difficulty with this design was that the compressor blades required machining and rotors used thrust bearings, opposed to the simpler blading of the 004 which were made of stamped steel.



And while the performance estimates were inflated for the HG-II/III they still would have been comparable to the Korean War era a/c if fitted with uprated engines (in the 3000 lbf thrust range), I don't see why high transsonic speeds wouldn't be possible (.96 Mach at alt planned for the HG-III) as the F-86 came fairly close to that (~.92 iirc) at best altitude with relatively little thrust. It would certainly be capable of a supersonic dive. (as would the HG-II, thought the engines would flame out due to the outboard placement with intakes resulting in compressor stall due to shock wave)

[red admiral]

So you want to seriously tell me the Atar 101 isn't a direct evolution of the 003 and essentially a scaled up version of the latter?

There was quite some progess between 1943 and 1946 in addition to extra resources at SCNECMA's disposal. It would not be possible to develop the Atar for German use in the timeframe because the effort was going into making the 003 work. The 003 was a good engine, considerably better than the 004. The Metrovick series were better, offering greater reliability, more power and less weight. This engine was developed into the AS Sapphire with pretty much the same design team. The Sapphire is not the same engine as the F.2 series, coming later after the problems (not many actually) with the F series had been found.

Given the pace of evolution of aircraft and (jet) engines at the time etc.

003 and 004 are maxing out at about 2300lbf. The new engine available in the time frame was the Hes 011 which never came close to making its designed thrust postwar. There weren't more powerful engines available for the Germans. Comparatively, the Nene and Derwent V had just been tested in the UK in addition to already more powerful Goblin. The difference in speed from the HII derivative is minimal, even going with the predicted performance. The M0.96 figure for the HG III is based on flawed data that effected all the fast Luft 46 planesThere was insufficient data for proper estimation in the transonic range, and no research to get any.

The wing sweep on the Me 262 was adopted for balance reasons, not aerodynamic. The 18° sweep puts up Mcrit by an entire 0.01. With the longer nacelles, both the Me 262 and Meteor were limited to around 0.81-0.82. The conception that the Me 262 was more advanced is flawed because all people fix on is the fact that it has swept wings. So has the C-47.

Admiral the Mk.I was the Meteor to fight V-1's (albeit somewhat unsuccessfully due to the jamming problems with the cannon)

The Mk I fought over the UK. The Mk III fought V-1s over Antwerp and did ground strafing, being ordered not to fly over German lines.

And while the performance estimates were inflated for the HG-II/III they still would have been comparable to the Korean War era a/c if fitted with uprated engines (in the 3000 lbf thrust range), and didn't the HG-III incorporate area rule into the design? (which would allow excellent speed with even underpowered engines, possibly supersonic with adequate engines)

I very much doubt it but as they were never built its rather hard to get a definitive answer. The early F-86 wasn't that much faster than the Meteor F.4 but the swept wings allowed for a higher Mcrit which means diving speed and more control. There was no area rule on the HG -III, it had yet to be invented. Actually, it does completely the opposite of what area ruling requires with a very large change in area because of the fuselage mounted engines. Mcrit might stay similar to the HG-III despite the extra wing sweep. The only way the design is going supersonic is vertically towards the ground or with a huge honking rocket attached.

[kool kitty89]

Yeah I edited my post on the area rule thing, however area rule did exist:

The area rule was first discovered by Otto Frenzl when comparing a swept wing with a w-wing with extreme high wave drag [1] working on a transonic wind tunnel at Junkers works in Germany between 1943 and 1945. He wrote an inventor message on 17 December 1943, with the title “Arrangement of Displacement Bodies in High-Speed Flight”; this was used in a patent filed in 1944.[2] The results of this research were presented to a wide circle in March 1944 by Theodor Zobel at the “Deutsche Akademie der Luftfahrtforschung” (German Academy of aeronautics research) in the lecture “Basically new ways to increase performance of high speed aircraft.” [3] The design concept was applied to a variety of German wartime aircraft, including a rather odd Messerschmitt project, but their complex double-boom design was never built even to the extent of a model.

On the HG-III agree it wasn't going supersonic w/out a steep dive.

But what about the HeS-30 (006) I mentioned, and the 003 topped out at 1,200 kp (2643 lbf) in the 003D with reaction compressor. (same type as the HeS-30)

And the 004E produced 1,200 kp with afterburner (1,000 kp dry w/out overrev, in in testing with overrev 1,100 kp dry) and in post war development as the RD-10 the RD-10F (developed 004E) produced 1,100 kp thrust dry in production models.

[kool kitty89]

One other thing that I forgot to mention was that, while the Me 262's ~18.7 degree sweep was primarily for CoG issues (though it did help a little), the Me 262 did use some advanced aerodynamic features.

It used a thin (11% root 9% tip TR) low drag airfoil with full span automatic LE slats and relatively thin (somewhat swept back) tail surfaces with an electrically operated variable incedence tailplane. (for trim, also useful for recovering from dives) Giving the a/c a critical mach number of .86 in Messersmitt testing and giving excelent high speed control characteristics.

One flaw, however, was a lack of airbrakes and thus it could not regulate speed (particularly in dives) like the Meteor or P-80. (I can't remember if early Vampires featured airbrakes)

[KrazyKraut]

This is obviously turning into another pointless battle of will that seem common here, so I will leave you to your opinion even though I think you base them on wishful thinking rather than trying to be objective. You are comparing an aircraft that didn't become operational until 2 years after the war to one that was available in mid to late '44 and assume that it would make it in time to be operational in numbers by late '45 (wishful thinking) and that it's potential enemy in question would've remained the exact same, eventhough evidence of its progress is plentiful. You also tell me, contrary to the all the books I have read on the subject, the developments of the 003 are in fact not (despite having the same German design team, which you continuously ignore), maybe you ought to contact some aviation historians and tell them they're all wrong.