Ta-152C equivalent to Tempest?

pattern14 said:

Few people seem to remember that the British attempt at a cheap mass produced single engined jet, the E1.44, was a complete flop.

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You have forgotten DH Vampire about as cheap as it was possible to build a jet. Part of the forward fuselage was built of Plywood

de Havilland Vampire - Wikipedia, the free encyclopedia

Few people seem to remember that the British attempt at a cheap mass produced single engined jet, the E1.44, was a complete flop.

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Thanks Fastmongrel; I was just about to say the same thing. Don't forget the enormously successful Vampire, of which over 4,000 were built.

The E.1/44 was originally built to Specification F.1/44 and started life on paper as the E.5/42 Ace, the name by which the E.1/44 was known, or the Gloster Gormless as its pilots called it. The E.5/42 differed from the E.1/44 and drawings of the F.1/44 (anyone confused yet?) featured the taller fin with the tailplane mounted on it as how the Ace was later modified and not the fuselage as the aircraft was completed. It could have been quite a good aircraft had it been prioritised and finished sooner, but Gloster lost interest in the project and by the time it was finished in 1948 it was too slow and overtaken by events.

Yes, great information Delcyros and yes, I agree with you; putting the He 162 into context as a first generation jet; its problems seem characteristic of its contempraries. Like its contemporaries, given the chance to mature, it would most certainly have been an excellent service jet with its performance, but with the fate of the Reich as it was, it was not to be. It was born out of desperation and the very thing that spawned it also resulted in its ultimate fate. As such it is overlooked as being anything other than a failed experiment, which might be a little harsh considering its potential, but that's life.

Despite his opinionated approach and arguable hypotheses, Brown's summary of the He 162 is apt:

"It would certanily have been an effective gun platform, and its small dimensions would have rendered it difficult to hit. Even if somewhat underpowered, it had good performance - it could certainly run rings around the contemporary Meteor - but it was no aeroplane to let embryo pilots loose on, and it would have demanded more than simply a good [Brown's italics] pilot to operate it out of a small airfield. Nevertheless as a back up for the formidable Me 262 it could conceivably have helped the Luftwaffe to regain air superiority over Germany had it appeared sooner. Personally, I shall always recall the He 162 with affection as it gave me some exhilarating hours in the air, and I cannot help but feel that the Allies were fortunate for, had another month or two and the necessary fuel been available, the He 162 might well have got in among our bombers in numbers at a time when desperate measures might just have achieved sensational results."

Hello nuuumannn
but one must remember that Brown has also written "The Volksjaeger Salamander, wit its pygmy size and very limited range, was an impractical proposition." Wings on my sleeve (2007) p. 138. French, who used a few post-war as a jet familiarzation a/c, were not fond of it, IIRC the main complain was its totally inadequate flight time. But as Delcyros wrote, all 1st generation jet fighters had their share of problems and He 162 had had very short development time.

Juha

".... it would have demanded more than simply a good pilot to operate it out of a small airfield."

'Aye, there's the rub', if I may quote the bard. Good or even competent pilots were one of the many things the Luftwaffe did not have an ample supply of in late 1944/early 1945.

Cheers

Steve

Yes, Juha, that is interesting; in Wings of the Luftwaffe, from where I took the earler quote, his opinions of it were high. This book was based on notes he had made at the time he flew these aircraft and throughout the book he quotes from the notes he kept. The contents originally appeared as a series of articles in Air Pictorial and Air International in the 60s and 70s prior to Wings being published. It's not surprising that in the intervening years he reassessed his position on the He 162; he's right; it was an impractical proposition and, like I said, it was a victim of the very thing that gave birth to it - the Nazis were desperate after all.

Here's further quotes from Brown about how he regarded it at the time. The first is a quote directly from his notebook that he wrote when he encountered it for the first time:

"An exciting looking aeroplane, though not exactly beautiful. There is so much wood around that it looks as though it has been built by a modelling enthusiast. Its narrow track undercarriage is likely to make it a handful in a cross wind. an oversize V 1 on wheels!"

"On the credit side [having just described its side slip problems] however, the aircraft had excellent directional snaking characteristics, making it a good gun platform. From this aspect it was the best jet fighter of its time, and I was certainly one to judge, having flown every jet aircraft then in existence."

"My first impressions of the Volksjager were not to change much, although I was to fly the little aeroplane quite frequently. It was like all German jets - a superb aeroplane in its element but quite a handful to take off and land. I had never met better flying controls yet they could be so easily mishandled..."

To anyone at the time the aircraft would have been eye opening, but by 2007, when Wings on my Sleeve was published, Brown had flown everything from the He 162 to an F-4 Phantom II and then some. A reassessment of his earlier thoughts was only natural.

I have a 87 English and a 88 German edition and as far I can judge the translation is accurate. In both books his comments are very positive regarding the He162.
cimmex

Hello Nuuumannn and Cimmex
yes, I had read Brown's earlier assesments on He 162 and I was at first rather surprised when I read the description in the Wings on mys sleeve but then I remembered that also his assesment of Zero had changed over the time, in Zero's case to more positive. My thought was that B. had re-valued the He 162 after reading on French assessments on it because IMHO the easiest way to explain the change of his oppinion on Zero is that the clearly more positive assessments of others had influenced him. Of course nuuumannn might be right that his later experiences with more mature jets had chanced his oppinion on He 162.

Juha

Juha said:

Hello Delcyros
what is the source of your quotes from the US evaluation report in your very interesting message #87?

Juha

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It´s in one of the NACA TN files but I have to look into that again. It´s not an evaluation per se, just a side comment, IIRC.

TIA delcyros, your info was very interesting indeed!

Juha

I have looked into some fuel data for various engines and 1st generation jets.

That makes for a nice mathematical challenge, which I ´d like to share with You.

First I pay attention to Bedienvorschrift He-162 mit TL-Triebwerk BMW-003, 1944 (issued 1945).

The He-162A2 had a max allowance of 772kg of internal aviation fuel, corresponding to a MTOW of 2866kg: one large fuselage tank 640ltr, two wingtanks with 140 ltr each for a grand total of 920ltr and 772kg (p.4). Alternatively, one normal 470ltr fuselage tank would be combined with an emergancy fuselage tank (170ltr) and the wingtanks with 140ltr each for a grand total of similar 920ltr.

The specific fuel consumption of the BMW-003E2 is given with 1.41 kg/hr/kp at SL and 100% thrust rating. The total consumption therefore is 1.128 t. per hour for 800kp thrust at Sea level, agreed?
Thus, the internal fuel buncerage is sufficient for a theoretical 41 minutes of powering the engine to 100% thrust at SL (corresponding to 427kts TAS -without short time overrew). If You substract fuel for warming up the engines, taxiing, acceleration and take off, the 30 minutes rating reproduced in the literature seems reasonable.


Now do some exercises with the following planes:

Yak-15
internal fuel capacity: 710 ltr / 590kg
RD-10 specific fuel consumption at SL and 100%: 1.44 kg/hr/kp
RD-10 100% SL thrust rating: 890 kp
What is the theoretical endurance at 100% power and Sea level, corresponding to 410kts TAS?

MiG-9
internal fuel capacity: 1625 ltr / 1349kg
RD-20 specific fuel consumption at SL and 100%: 1.41 kg/hr/kp
RD-20 100% SL thrust rating: 800 kp
What is the theoretical endurance at 100% power and Sea level, corresponding to 475kts TAS?

P59A
internal fuel buncerage: 470 US gallons / 1098ltr max
J31 GE-5 specific fuel consumption: 1.25 lbs/hr/lbs thrust at 100%
J31 GE-5 100% thrust rating: 3,100lbs (acc. to Kay)
What is the theoretical endurance at 100% power and Sea level, corresponding to 326kts TAS?

P80A1
internal fuel buncerage: 470 US gallons / 1779ltr max (some sources say 435 US gallons / 1647 ltr max, altough I believe that´s already accounting for fuel needede to warm up, taxiing take off and acceleration)
J33 GE-7 specific fuel consumption: 1.22 lbs/hr/lbs thrust at 100%
J33 GE-7 100% thrust rating: 3,825lbs (acc. to Kay)
What is the theoretical endurance at 100% power and Sea level, corresponding to 461kts TAS?

XP84
internal fuel buncerage: 378 Imp gallons / 1709ltr max
J35 GE-1 specific fuel consumption: 1.12 lbs/hr/lbs thrust at 100%
J35 GE-1 100% thrust rating: 3,750lbs (acc. to Kay)
What is the theoretical endurance at 100% power and Sea level, corresponding to 506kts TAS?

Vampire F Mk I (late production with Goblin II)
internal fuel buncerage: 202 imp. gallons max (=918.3ltr or 1680lbs) (no drop tanks possible)
Goblin II specific fuel consumption at SL and 100%: 1.233 lbs/ hr/ lbs thurst
Goblin II 100% SL thrust rating: 3000lbs
What is the theoretical endurance at 100% power and Sea level, corresponding to 443kts TAS?

Meteor mk III (mid block production lot, compare note below)
internal fuel buncerage: 490 imp. Gallons or 2227.6 ltr or 4075lbs -note for a varying tankage account in Flight magazine:

"at present the air-craft has a standard permanent tank capacity of 330 gallons but has only been cleared for
a normal tankage of 275 gallons. When the R.A.F. begins to take delivery of its Meteor IVs the machine will doubtless
be cleared for carrying not only its full tankage of 330 gallons but also the ventral drop tank of 180 gallons for which provision has been made."

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-Flight dated feb. 1946, p.157.
Dervent II specific fuel consumption at SL 100%: 1.17 lbs / hr/ lbs thrust
Dervent II 100% SL thrust rating: 2200lbs *2 (twin engined A/C)
What is the theoretical endurance at 100% power and Sea level, corresponding to 424 kts TAS?

Me-262A (1944 production model)
internal fuel buncerage: 2600ltr = 2158 kg (other sources mention 2000ltr, the rear 600ltr fuselage tank was shipped for long endurance missions and could be removed when not needed. Typically with poor directional stability due to cog shift aft)
JUMO-004B specific fuel consumption at SL and 100%: 1.44 kg/hr/kp
JUMO-004B 100% SL thrust rating: 890 kp *2 (twin engined A/C)
What is the theoretical endurance at 100% power and Sea level, corresponding to 450kts TAS?

What conclusions do You draw from these theoretical but comparative figures You arrive with?

Once You have gone through this exercise You will find the "low endurance He-162" hype beeing just another myth busted. The reason lies in different definitions how to attain endurance figures, whiches meaning hasn´t been comprehended by many authors...
I need to correct my previous statement of the Vampire F1 endurance, which was taken unreflected from aircraft performance charts and refer to throttled back condition.

As thorough as your research is, Delcyros - and I don't want to detract from your efforts at all, but the problem with quoting figures from manuals is that in real situations the figures available in tests or trials were invariably not always attainable to frontline operational aircraft for varying reasons. Just because the figures might state a particular engine is not as thirsty as other engines, in practise the pilots who flew the aircraft might have a different view owing to outside factors not taken into account by official figures; finish of the aircraft, for example owing to the rigours of service will degrage its performance because of increassed drag etc. There are countless examples of aircraft not meeting their performance figures in practise. The He 162s and other types in general that Brown flew were not factory fresh; some had been flown in service and were the worse for wear for it.

That´s fair and well. We understand numerous differences between theoretical and practical endurance (both operationally, the most important beeing the avaiability of aviation fuel for the Luftwaffe as well as technically with regard to f.e. unusable quantities of fuel in the fuel lines). We know that JG1 pilots in part were flying their mounts not topped off with fuel due to the sparse quantity avaiable in arpil 45). However, if we talk about design defects and in this context adress low endurance of the He-162A as a specific weakpoint in the design we should not make the mistake in forgetting the context these statements refer to. And while it may be possible to be worse than spec (the british post war tested He-162 f.e. suffered from a jet engine with performances far below specification) it hardly is possible to be better than specification in terms of buncerage and specific fuel consumption. As I mentioned previously, I found the claim of 30 minutes low altitude endurance of the He-162A after allowances for ground handling, take off and acceleration to be believable in light of the fuel tankage and consumption figures of the engine.

But what has been missed is that the internal fuel capacity and corresponding endurance of the He-162A is -contrary to popular believe- not to different to the endurance on internal fuel of the Meteor III and XP-84 (within seven and four minutes, respctively -not accounting for the fact that Meteor III´s only beeing cleared for 275 gallons internal in 1945) and roughly similar to the P80A1 Shooting Star (it differs by seconds rather than by minutes) and somehow superior to other first generation jets like P-59A, MiG-9, Yak-15 and Vampire MkI (the latter would be closer to 1 quarter an hour endurance after allowances for ground handling, take off and acceleration and would fail to meet 30 minutes endurance at 100% thrust on any static ground test) . But while nobody hesitates to hark on the He-162A´s design defect of low endurance they hardly ever mention that contemporary jets existed to have a significantly worse endurance than the He-162. I wonder why that is, one reason is possibly that in wartimes these defects are operational issues and thus exposed more clearly than in peacetime operation (mostly P80, Vampire and soviet A/C). But maybe it´s also uncritically reflected accounts and perception issues. The He-162 had lower endurance than the Me-262 (by roughly ten minutes) and the latter had significantly lower endurance than the Ar-234B on internal fuel (by ~23 minutes), making the He-162A the shortest legged german jet fighter (we are not talking about rocket interceptors here) but the pilots who flew them couldn´t possibly know how poor the others endurances were...
The truth is that all 1st generation jets had exceptionally poor low altitude endurance, which is why most of them received drop tanks sooner or later and were advised to cruise at high altitude.

Hi Delcyros, my comments about figures were not specifically about this particular topic, but about figures and actual operational aircraft in general, although referencing the figures you mentioned. I don't stick specifically with published figures as the last word on the performance of an aircraft for this reason - each individual aeroplane is different and behaves differently and is often subject to maintenance issues that others might not be subject to. I like to think of official figures as the designer's benchmark by which the aircraft could reach, but for whatever reason might not. In testing, many types, of course did not reach their official figures stipulated in the manuals.

As for the He 162's range I agree with you, by comparison with existing jets, it was not too shabby, to the extent that in Brown's initial flight tests he did not comment on the subject. It seems the He 162 could have carried more fuel; here is an excerpt from Wolfgang Wagner's book The History of German Aviation; The First jet Aircraft;

"The fuel tank in the fuselage held 790 liters [sic]. The 30 liter tank for starting the engine was located in the wing center section.The two 320 liter wing tanks were housed in either wing half. Other sections of the wing could hold 700 liters of fuel, plus room for an additional tank in the leading edge. The entire wing could also be used to carry 900 liers of fuel, so that if the gross weight allowance was increased the aircraft would have enough reserves for greater ranges."

But while nobody hesitates to hark on the He-162A´s design defect of low endurance they hardly ever mention that contemporary jets existed to have a significantly worse endurance than the He-162. I wonder why that is, one reason is possibly that in wartimes these defects are operational issues and thus exposed more clearly than in peacetime operation (mostly P80, Vampire and soviet A/C). But maybe it´s also uncritically reflected accounts and perception issues.

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I guess it depends on what is being used as a frame of reference. Post war analysts might have used existing aircraft performance - i.e. piston engined machines as their source of comparison, so by those standards, yes, the He 162 did have poor range, as did all first generation jets, but we know that already. As we all should know, the transition from piston engined aircraft to the first generation in service jets was far from smooth, although at the time the presumption was very much that they would be as easy to fly and handle. The high rate of incidents and accidents of Vampire and Meteor pilots in the RAF throughout the late 40s and 50s is testimony to the fact that the early jets had a bit of a way to go before they were reliable and 'easy to fly' enough for a tyro pilot to make a successful transition from earlier types to them. A number of early jet losses in the RAF was down to a tendency to ignore the fuel gauges, as well as the usual reliability issues with engines and systems, also cockpit ergonomics and design faults often arises.

Brown himself comments on the fact that he had no training whatever on many of the aircraft he flew and in the absense of notes of any sort, manuals not necessarily being available, was expected to take a cursory glance round the cockpit before kicking its tyres and jumping in for a test flight.

buncerage

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You might have to enlighten me on this term, Delcyros.

cimmex said:

Czech built Me 262 (Avia S92 and S199) flew till 1957
cimmex

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Good point; I had over looked the Avia. To the best of my knowledge they were only built in very small numbers, never used operationally, and primarily served as a trainer.

"bunkerage" is simply the amount of fuel a vehicle carries. I thinks it most commonly used wrt ships, eg a KGV had xxxxx tons of oil bunkerage.

Hello
according to Philippe Couderchon's The Salamander in France article in Aeroplane April 2006 the French He 162 No 1 (ex-WNr 120223 "Yellow 1" of 3./JG 1) had according to a French memo usable fuel capacity of 640lit (470 + 170 for reserve.
And according to the 2nd part of the article in the May 2006 Aeroplane Lt Jean Bourguignat, who flew He 162s twice remembers that No 2 (ex-WNr 120015 "White 21" or "Yellow 21" of 1./JG 1) had a larger fuel tank (650+170lit) than the other two (No 3 was ex-WNr 120093 "White 2" of 1./JG 1).
It would be nice to know what any French pilot who flew both He 162 and Vampire F.1 thought of those two planes.

Juha

I don't think that a French pilot had access to a Vampire FI before 1950 and even 1952 for a Mistral SE 535 (French built Vampire). At this time no He162 was operational any more.
cimmex

Hi Nuumann,

I definetely agree in Your points. Since the fuel capacity (the naval term buncerage is my mistake, thanks for the pointer) has been a matter of discussion, I may offer some of my findings here.

As for the He 162's range I agree with you, by comparison with existing jets, it was not too shabby, to the extent that in Brown's initial flight tests he did not comment on the subject. It seems the He 162 could have carried more fuel; here is an excerpt from Wolfgang Wagner's book The History of German Aviation; The First jet Aircraft;

"The fuel tank in the fuselage held 790 liters [sic]. The 30 liter tank for starting the engine was located in the wing center section.The two 320 liter wing tanks were housed in either wing half. Other sections of the wing could hold 700 liters of fuel, plus room for an additional tank in the leading edge. The entire wing could also be used to carry 900 liers of fuel, so that if the gross weight allowance was increased the aircraft would have enough reserves for greater ranges."

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and Juha´s comments later:

French He 162 No 1 (ex-WNr 120223 "Yellow 1" of 3./JG 1) had according to a French memo usable fuel capacity of 640lit (470 + 170 for reserve.
And according to the 2nd part of the article in the May 2006 Aeroplane Lt Jean Bourguignat, who flew He 162s twice remembers that No 2 (ex-WNr 120015 "White 21" or "Yellow 21" of 1./JG 1) had a larger fuel tank (650+170lit) than the other two (No 3 was ex-WNr 120093 "White 2" of 1./JG 1).

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The original main fuel tank in the fuselage was supposed to be an unprotected 790 ltr tank. However, EHAG Aktenvermerk 11/45, dated february 1945 states explicitely at page 2 that

"Firma meldet den Verlust von 150 ltr. durch Abschneiden des Rumpfbehälters, um kleinere Schwerpunktwanderung zu erhalten"
(translation attempt:
"Company reports the loss of 150ltr caused by cutting the fuselage tank in order to attain a smaller cog /trim shift"

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My guess is that Wagner didn´t traced down all Heinkel Aktenvermerk sources for updating his data on fuel capacity and reproduced the intended size of the main fuel tank, not the actual one executed.
In this context it is mentioned that the freed space would be sufficient to allow 80 instead of 60rpg 30mm MK108 ammo to be carried. However, a permanent weight instead of a used up weight was more desirable and 42kg of ballast were added to the cockpit if the large fuselage tank was to be shipped (EHAG AKTENVERMERK 66/45). This should be replaced in april 45 production by an armoured windscreen and EZ42 computing gunsights for weight neutrality.
Note that only the small, 450ltr measuring fuselage tank could be used in connection with the 170ltr measuring emergancy fuselage fuel tank (Baubeschreibung pilot notes from feb 45)! Also, there appear to be two wingtank sizes avaiable. EHAG AKTENVERMERK 11/45 notes that the total fuel capcity is:

Brennstoffinhalt bei Fläche mit kleinen Behältern insgesamt 960ltr., Start- Rollstrecke 800m
(...)
Brennstoffinhalt bei Fläche mit großen Behätern insgesamt 1300ltr., Rollstrecke 1100m

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These figures differ a bit from mine because I ignored the small fuel tank for starting the engine. The corrected figures for the large wingtank would in turn make the internal fuel capacity and corresponding endurance of the He-162 taking the lead over other 1st generation jet fighter with a theoretical endurance of 57 minutes on SL and 100% (except the Ho-229, which I wouldn´t classify as a "fighter type" aircraft). The main fuselage fuel tank was of self sealing type, the wing tanks (and emergancy tank) were not. Appearently, the french examples were flown WITHOUT wing tanks at all. This was possible and resulted in a very low take off weight (around 2.5t), but has been used only for pilot familarisation planes, which were deemed unfit for operational service (caused by missing automatic jet nozzle controll, which degraded thrust by 1/3 and speed by 1/6). Admittently, many He-162A manufactured and delivered before april 1945 fall in this category.

hope this helps,

cimmex said:

I don't think that a French pilot had access to a Vampire FI before 1950 and even 1952 for a Mistral SE 535 (French built Vampire). At this time no He162 was operational any more.
cimmex

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Hello Cimmex
according to Jones' De Havilland Twin-boom Fighters (2004) French ordered 30 ex-RAF Vampire F.1s in 1948, delivery was made in 4 weeks with the last a/c arriving on 8 Jan 1950. IMHO it is very probable that some of the French pilots who had flown He 162 in 1947 - 48 also flew Vampire F.1 later on during their career.

Juha