p-80 V Me 262

[Kurfürst]

Originally Posted by kool kitty89

The 262 only had the speed advantage at medium altitudes as its speed dropped once above a certain point. At the P-80A was faster but by less than 10mph more than the 262's optimum. The 262 had lower roll characteristics due to its long engine nacelles while the P-80's wings were unobstructed. There was a chart that compares their peformance on the first page of this thread. Also the P-80 had quite an altitude advantage (~1000ft).

I am not sure of this, but I haven't seen an actual speed chart for any P-80 variant so far. Common sense though tells me that since the P-80s maximum speed of nearly 900 kph was reached at SL, it means that at all altitudes it was slower than that. The 262 peaked out at 6000m.

I'd love to see that 262/80 Wright Field tests, too. Heard about it so many times..

[kool kitty89]

Did you see the chart on page 1? It compares both plane's capabillities as well as top speeds at various altitudes.
Also I think the P-80's better low altitude performance is due to the 800lb thrust water-alcohol boost. From wikipedia: "The J33 was a US-produced development of Frank Whittle's early Rolls-Royce Derwent, enlarged to produce dramatically more thrust, starting at 4,000 lbf and ending at 4,600 lbf with an additional low-altitude boost to 5,400 lbf with water-alcohol injection." Without this the top speed is substancially lower.

[Kurfürst]

Yes, but I am cautious with charts with limited background information.

The thrust used is simply not known. Correct me if I am wrong, but P-80A is a later and powerful version than the YP-80 that saw some flights towards the end of the war. It's not known wheter these results for the P-80 are measured or early calculations, wheter they are for a single plane or an avarage of production planes.

The Me 262 figures, for example, appear to be coming from a mass-measurement of serial production Me 262s, involving some 120 plane's avaraged data IIRC !

[drgondog]

Kurfurst - the first P-80A deliveries started in late Februart 1945. I believe both the GE and Allison J-33's (GE-9 and -11, Allison A9) had 3850 pounds of thrust.

I've seen teo references that stated the higher SL speed which is curious to me as a jet engine is more efficient when the temperature difference between intake and exhaust is greater - and it is a lot colder at 40,000 feet!

I'm still looking for different data on the P-80C delivered with 25 Allison with 5400 pounds of thrust to see the best altitude for TAS.

curious..

[JoeB]

Originally Posted by drgondog

I've seen teo references that stated the higher SL speed which is curious to me as a jet engine is more efficient when the temperature difference between intake and exhaust is greater - and it is a lot colder at 40,000 feet!

I'm still looking for different data on the P-80C delivered with 25 Allison with 5400 pounds of thrust to see the best altitude for TAS.

The temperature effect is dominant at constant pressure. So for example the s/l thrust of an turbine engine decreases noticeably at higher ambient temperature, important everyday effect for takeoff.

But, when increasing altitude you're decreasing air density a lot and thus mass flow, so the max thrust declines. The drag on the airplane is also tending to decline with altitude, but the combination of those offsetting effects was that early jets had flatter characteristics of speed v altitude than props usually did and some jets did max out at s/l. A slightly later plane more or less comparable to the F-80C is the F9F-2: this link shows its complete speed/altitude curves, it's either max at s/l or almost completely flat depending on configuration, see pg 6.
http://www.history.navy.mil/branches/hist-ac/f9f.pdf

This tendency increased as fighter performance increased and planes got closer to the Mach drag rise in level flight. The lower the altitude the lower the Mach for a given speed so the drag rise is delayed. So, for example the F-86 and MiG-15 both maxed out at s/l.

This changed for supersonic afterburning fighters because the turbine inlet temp no longer limited mass flow, the afterburner did, plus drag characteristics change in supersonic flight. Their max TAS often occurred as high as the tropopause, where air temp stops falling (ca. 50k ft). I don't know the speed/altitude characteristic of plane like the F-22 which can well exceed M1 at high altitude w/o afterburner, but that's getting pretty far OT.

Another example back in WWII was the Meteor I. It didn't max at s/l but the difference in max speed w/ altitude was smaller than for props, so it was faster than most prop fighters at low altitude, but slower the best props at medium altitude. Hence its combat niche as V1 interceptor at low altitude.

Joe

[drgondog]

Originally Posted by JoeB

The temperature effect is dominant at constant pressure. So for example the s/l thrust of an turbine engine decreases noticeably at higher ambient temperature, important everyday effect for takeoff.

But, when increasing altitude you're decreasing air density a lot and thus mass flow, so the max thrust declines. The drag on the airplane is also tending to decline with altitude, but the combination of those offsetting effects was that early jets had flatter characteristics of speed v altitude than props usually did and some jets did max out at s/l. A slightly later plane more or less comparable to the F-80C is the F9F-2: this link shows its complete speed/altitude curves, it's either max at s/l or almost completely flat depending on configuration, see pg 6.
http://www.history.navy.mil/branches/hist-ac/f9f.pdf

This tendency increased as fighter performance increased and planes got closer to the Mach drag rise in level flight. The lower the altitude the lower the Mach for a given speed so the drag rise is delayed. So, for example the F-86 and MiG-15 both maxed out at s/l.

This changed for supersonic afterburning fighters because the turbine inlet temp no longer limited mass flow, the afterburner did, plus drag characteristics change in supersonic flight. Their max TAS often occurred as high as the tropopause, where air temp stops falling (ca. 50k ft). I don't know the speed/altitude characteristic of plane like the F-22 which can well exceed M1 at high altitude w/o afterburner, but that's getting pretty far OT.

Another example back in WWII was the Meteor I. It didn't max at s/l but the difference in max speed w/ altitude was smaller than for props, so it was faster than most prop fighters at low altitude, but slower the best props at medium altitude. Hence its combat niche as V1 interceptor at low altitude.

Joe

You're right Joe - I should dragged out the propulsion books rather than rely on a memory 40 years out of current

[kool kitty89]

I think the Me-262 airframe was superior to both the P-80 and the Meteor, but the plane itsself was not optium. I said earlier that the 262's long nacelles wewe a problem with roll, well I should correct myself. I should have said that the weight of the Junkers 004 (more than 1600 lbs each) engines was what limited roll and with smaller/lighter engines like the originally planned BMW003s (~1300lbs) or, even better, the more powerful smaller, lighter HeS-30 had it not been canceled (only 860 lbs with over 2000lb thrust) it certainly would have been superior (but with such engines the He-280 might even be close to superior.

As it was the 262 was far superior to the F1 meteors (only 417mph max) but the F3, which was deployed over Germany for armed recon and ground attacks in early 1945) was upgraded with better aerodynamics (better, more strongly raked canopy and longer nacelles) was capable of over 490mph at altitude even with only the older 1600lbf welland engines (which only the first 13 F3s were fitted with as the 2000lbf derwent I wasn't available yet) and with the rest of the F3s fitted with derwents their speed would bave been markedly increased. Though the F3 was still about 50mph slower than the 262 its ligher engines (under 1000lbs each) would have allowed for better roll characteristics and its engines were more durrable, lasting many times longer than the 004 engines (which lasted for only around 20 hours with an avrage pilot) and it also had a flight ceiling advantage of a couple thousand feet.(40,000ft compared to the 262's 37,500 ft max) I'm not saying the F3 meteor is superior overall, but it would at least give the Me-262 a run for its money.

Im not sure how the gun accuracy compared, but even if the F3 meteor's was better this wouldn't be a fair comparison because the 262's 30mm cannon was equipped primarily for bomber attacking (at which it was quite effective) and not for dogfights. As a side note, when the F3s were first stationed in germany in '45 they were often mistaken for Me-262s by friendly anti-aircraft implacements and sometimes even other friendly aircraft. This led to the Meteors being painted white to distiguish them. Luckily there wer no friendly kills resulting from these accedents and the only meteor lost in service over Germany was in a mid-air colission durring bad weather.

Also I think the YP-80A performed about the same as the P-80A but had more engine troubles mostly caused by the fuel-pump and, to a lesser extent, the air intakes (many of which resulted with fatal results). But the P-80A wa already in production before the end of the war anyway:
"The initial production order was for 344 P-80A's after USAAF acceptance in February 1945. Eighty-three (83) had been delivered by the end of July 1945 and 45 assigned to the 412th Fighter Group (later redesignated the 1st Fighter Group) at Muroc Army Air Field."

[delcyros]

Originally Posted by kool kitty89

Though the F3 was still about 50mph slower than the 262 its ligher engines (under 1000lbs each) would have allowed for better roll characteristics and its engines were more durrable, lasting many times longer than the 004 engines (which lasted for only around 20 hours with an avrage pilot) and it also had a flight ceiling advantage of a couple thousand feet.(40,000ft compared to the 262's 37,500 ft max) I'm not saying the F3 meteor is superior overall, but it would at least give the Me-262 a run for its money.

I cannot fully agree here. Both planes have a comparable linear acceleration (the Me-262 tops out at high speed) and a fairly identic climb speed (the Meteor tops out at very high altitude) but I haven´t seen any details about the roll charackteristics. As a matter of fact, the roll speed is also dependent on the deatils of aerodynamic lift distribution and the controll surfaces, from which I haven´t seen figures to draw conclusions on.
I would also like to point out that the engine life is relative to the turbine section only. It could be as high as several hundreds of hours for -004A and as low as 6 hours for early production lots of -B-1 serial engines (it typically levelled off at 20 hours for the 004B-3 with hollow air cooled blades). However, the turbine section of the engine could be replaced in 20 minutes by experienced mechanics, after which the engine was cleared for another 10 hours. After these total of 30 hours, the engine has the be disassembled and investigated by a engine producer workshop, with the option of another 20 hours (this barely happened as there were lot´s of new engines coming in 45, they simply replaced the engines as a less time consuming measure).
More importantly, the Meteor was a flight restricted airframe, not cleared for acrobatics and with a comparably low critical Mach figure. Both isn´t good in high speed combat, so I don´t think the MK 3 is up to par with the -262 in it´s fighting abilities.

Originally Posted by kool kitty89

Im not sure how the gun accuracy compared, but even if the F3 meteor's was better this wouldn't be a fair comparison because the 262's 30mm cannon was equipped primarily for bomber attacking (at which it was quite effective) and not for dogfights. As a side note, when the F3s were first stationed in germany in '45 they were often mistaken for Me-262s by friendly anti-aircraft implacements and sometimes even other friendly aircraft. This led to the Meteors being painted white to distiguish them. Luckily there wer no friendly kills resulting from these accedents and the only meteor lost in service over Germany was in a mid-air colission durring bad weather.

Interesting, I hadn´t known much about the details of Meteor combat sorties over europe. The white camouflage however is a serious disadvantage, I think. No doubt, the four 20mm guns of the Meteor are better suited for high speed combat, nevertheless the -262 is somehow a one shot killer...

The YP-80 remains somehow a mystery to me. Does anybody know wheter or not there is a flight instructions manual for this A/C (or the P-80A) online?

kind regards,
delc

[Glider]

Originally Posted by kool kitty89

I'm not saying the F3 meteor is superior overall, but it would at least give the Me-262 a run for its money.

I believe the above is the key statement. In real life, few 262's were destroyed in 'open combat' the vast majority were caught on take off or landing. Once they had their speed up they were almost untouchable, giving them a huge tactical advantage.
Having Meteor F3's around would have gone a long way to removing that advantage.

An observation of the Meteor IV. Although it didn't enter production until 1947, it first flew in July 1945 with the delay not caused by any technical difficulties, it was a decision based on the likelyhood of war and the financial position of the UK. Had the war continued for another 12 months, there is little doubt that the Meteor IV would have been entering service in roughly the same timescales as the P80 and of course the Vampire.

[kool kitty89]

I pretty much agree with your responces. The disadvantage of heavy engines limiting manuverabillity was speculation on my part. I know the control surfaces have alot to do with manuverabillity, but since they never sucessfully used any other engines to compare performane its hard to tell.(The large and thick wings on the P-59 heavily contributed in its poor performance, the high area and span limiting maneuverability and the thickness contributing to poor top speed)

The low mach number of the meteor was greatly impacted by the nacelle design and this was fixed on the F3 but not until later in production (after this was changed the earlier F3s were refitted with new nacelles) but I'm not sure if this came in time forthe meteors serving over Germany). Also the Germany stationed meteors managed to destroy ove 40 german aircraft in their ground attack missions, tough none were in flight). Also I think the white paint would have helped more than it hurt since by this time in the war friendly fire waold have been more of a danger than the remaining German ground implacements.

The engine turbines were the biggest difference between the prototype 004s ond the production models. What I meant by durrable was that the steel turbines couldn't be abused as much as the british engines though this still wasn't a huge disadvantage (actually some of the pre-production 004Bs passed 100 hour tests but these tests were ground only on very well quality controlled producs).
RG Lunatic (I know that he caused alot of fuss and did deserve to be banned for lack of self controll and we all probably have mixed feeling about him) once said that lack of advanced industial science and industrial ability in germany made them incapable of producing sufficient numbers of engines and the V-1 and V-2 were a wast of time compared to their realitive effectiveness. I agree to an extent to the V-2 comment and to the V-1 to a lesser extent (it was fairly affective for its cost), I have to dissagree about the engines. They produced them fine in quantty (the hollow, air-cooled blades was an ingenious idea) and the industry wasnt all that far behind in metalergy as they produced stainless steel in quantity when they had access to sufficient chromium but lack of this durring the war scratched stainless steel off the list of prduction-quantaty materials. Though I'm not sure why they didn't use nickel-steel as this has good high temp properties and I don't think nickel was too scarse to be used for this and the steel would have been greatly improved for these purposes with only 10% nickel added though higher pecentages would have been even better. Plain nickel would have also worked well without the need of cooling though I don't think they had enough to use in this manner. Nickel and nickel alloys are still the primary material for use in gas turbine blades today.

Had the He 280 been produced (which would have required that at least one of Heinkel's class 1 jet engines be produced, preferably the HeS-30) it certainly havebeen a better fighter than the 262 because of its high maneuveabillity (in moch combat it outmaneuvered a FW-190), but it would have been a worse interceptor as it's speed was less due to the great speed aerodynamics (low drag area). So I think the 280 would outfight the meteor as well and probably the P-80A due to it's high maneuverability and ample speed.

Just imagine would have happened if Heinkel could have escaped Germany and defected to the allies with some of his designs in 1942. (this wouldn't have heen an unthinkable possibillity based on Heinkel's vew of the Nazis and especialy when they took over his company by "nationalizing" it in 1942. Though the nazis probably had a close watch on him and escape would have been unlikely. Still it would have been neat if he had somehow managed to leave and smuggle out copies of the HeS-30 and He 280 and gone to the allies for sactuary and in hopes that his designs would have been used. Though I still am unsure of why he didn't do somthing like this after the war...

[delcyros]

The low mach number of the meteor was greatly impacted by the nacelle design and this was fixed on the F3 but not until later in production (after this was changed the earlier F3s were refitted with new nacelles) but I'm not sure if this came in time forthe meteors serving over Germany).

I believe that this may have been improved but the problem never was fixed in the sense of beeing "cured". Even with long engine nacelles, the Meteor suffered from an appreciably lower crit Mach figure compared to the -262. This should be regarded as a tactical disadvantage.

Also the Germany stationed meteors managed to destroy ove 40 german aircraft in their ground attack missions, tough none were in flight). Also I think the white paint would have helped more than it hurt since by this time in the war friendly fire waold have been more of a danger than the remaining German ground implacements.

Yes, the closest they came to jet vs jet combat was an attack on an Ar-234B airfield. My problem with the white camouflage is that it is easier to distinguish. The few remaining german medium AAA by this time was equipped with the advanced Askania Zielgerät 43/44, which could track low level intruders and compute advance helm points up to 1250 Km/h.

RG Lunatic (I know that he caused alot of fuss and did deserve to be banned for lack of self controll and we all probably have mixed feeling about him) once said that lack of advanced industial science and industrial ability in germany made them incapable of producing sufficient numbers of engines and the V-1 and V-2 were a wast of time compared to their realitive effectiveness. I agree to an extent to the V-2 comment and to the V-1 to a lesser extent (it was fairly affective for its cost), I have to dissagree about the engines. They produced them fine in quantty (the hollow, air-cooled blades was an ingenious idea) and the industry wasnt all that far behind in metalergy as they produced stainless steel in quantity when they had access to sufficient chromium but lack of this durring the war scratched stainless steel off the list of prduction-quantaty materials. Though I'm not sure why they didn't use nickel-steel as this has good high temp properties and I don't think nickel was too scarse to be used for this and the steel would have been greatly improved for these purposes with only 10% nickel added though higher pecentages would have been even better. Plain nickel would have also worked well without the need of cooling though I don't think they had enough to use in this manner. Nickel and nickel alloys are still the primary material for use in gas turbine blades today.

My impression, beside all other things was that RG Lunatic is a very knowledgable Person. I had enjoied his valuable contributions, even (-better: because!) if they may sometimes have been controversial. His positions were usually well founded and he is a potent fighter for arguments. His approach from an techno-economical point of view is attractive and deserves to be mentioned here. He once stated that reliable jet engines couldn´t be produced by Germany outside the labs but I think he missed out some points. Out of the 5000+ Jumo-004´s which were produced in ww2 Germany, he considered 30-40% working jet engines. But this hardly could be the case. There is plenty of evidence from the -262 Werknummern database that around 1500 -262 have been finished (or worked so far as to receive Werknummern). Each of those takes two -004´s so that are around 3000 Jumos. Add 300-500 Jumos for the Ar-234 and around 50 for various prototypes and You have a minimum of 3350 -004 jet engine which were used. Naturally, several Jumos have been replaced on the planes following the end of their service life and a number of Jumo´s were used for training and tooling purposes. Therefore I regard the "reliable" output for jet engines to be at least 80% (conservative estimate). However, RG certainly could return a good argument and it is bad he isn´t around anymore.
Nickel also was considered a scarce ressource in Germany, hence the adoption of Tinadur and Chromadur as turbine alloy.

Just imagine would have happened if Heinkel could have escaped Germany and defected to the allies with some of his designs in 1942. (this wouldn't have heen an unthinkable possibillity based on Heinkel's vew of the Nazis and especialy when they took over his company by "nationalizing" it in 1942. Though the nazis probably had a close watch on him and escape would have been unlikely. Still it would have been neat if he had somehow managed to leave and smuggle out copies of the HeS-30 and He 280 and gone to the allies for sactuary and in hopes that his designs would have been used. Though I still am unsure of why he didn't do somthing like this after the war...

Ernst Heinkel was "invited" to the USSR post war. Better call it "required". He worked with Gurowitsh and all the early soviet ejection seats are derivates from Heinkel models. Heinkel wasn´t much into jet engines at all (he perhaps delayed the HeS-030 project more than accelerated it) but he had the right impetus and showed initiative to advance the by then new field much.
I am undecided how he would impact allied efforts if he defects hypothetically. In the UK I am convinced it wouldn´t matter if Heinkel is around or not. In post war times the UK had no active interest in german technician, one might even go so far as to say they disliked them (actually they had a reason!). The US are a bit different as they were interested in solutions and Heinkel had plenty of experience with providing such.

[Soren]

The most deciding factor here though is that while the British could've made the Meteor just as fast as the Me-262 they couldn't make it as effective a fighter, the Meteor's airframe simply not being capable of handling the same high amount of stress occuring in high speed maneuvers as the Me-262.

Another quite decisive factor is that the Me-262, along with a high aspect ratio wing, features wing leading edge slats which greatly improve high speed high G turn performance. The Meteor has to do with a low aspect ratio wing with center fixed engines disrupting airflow, and, its got no LE slats.


As to the Me-262 A-1a's performance, well the official Messerschmidt AG figures are very conservative and represents guaranteed performance while taking into consideration that by late 44 to 45 the Jumo 004's being manufactured were suffering massively in terms of lack of available high temp. resistant metals and in the end hasty workmansship - thus performance from batch to batch often varied alot.

The captured examples of Me-262 tested by the RAF topped 900 + km/h in straight flight, which is 30 km/h faster than the guaranteed performance brought forth by Messerschmidt AG.


Keep up the good debate guys

[kool kitty89]

I still think the He 280 (with appropriate engines) would have been a better dogfighter than the 262, early-model P-80, or early meteor (Mk3 or 1) Though its range wasn't that great (though drop tanks could have improved this) it had excelent maneuverabillity, especially for a jet fighter (it outmaneuvered a FW 190 in mock combat).

I can't vouch for its optimum speed (ie in its best configuration using HeS-30s) because it was never tested with HeS-30s and with the underpowered HeS-8 (600kgf, 1320 lbf each) it was tested with its top speed was around 420mph at low level. The Junkers 004 engines it was later tested with were poorly matched to the airframe and offered poor performance (they were about twice as heavy and significantly larger than the originally intended engines: more than twice the length and slightly wider of the HeS-8 and 50% longer and 30% wider than the HeS-30) Most sourses I've seen projected the top-speed (with HeS 30s) to be over 500mph and as high as 540mph at altitude. (from The Messerschmitt Me-262 Schwalbe / Sturmvogel and Heinkel He 280 archive file -some great pics on this site!)

Above: the original engine configuration, below: with Junkers 004 engines.

[Glider]

Originally Posted by Soren

The most deciding factor here though is that while the British could've made the Meteor just as fast as the Me-262 they couldn't make it as effective a fighter, the Meteor's airframe simply not being capable of handling the same high amount of stress occuring in high speed maneuvers as the Me-262.

Where on earth did you get the idea that the Meteor couldn't take the stess's involved in high speed maneuvers. It was around for a long time, flown by many countries and I have never heard of a problem with the aircraft's stress levels.

[Sir Francis]

Hey,

A mate got this off some website, can't find it again though.
Post WW2 tests-USAAF comparison P80 v Me262 concluding "Despite a difference in gross weight of nearly 900kg the Me262 was superior to the P80 in acceleration, speed and approx same in climb performance. The Me262 apparantly has a higher critical Mach number, from a drag standpoint, than any current Army Air Force fighter".

I suppose they are referring to the swept wing drag benefit (even though the engines must be a drag.....)