Swept or straight wings for WWII jet fighters?

[Romantic Technofreak]

We already had the discussion about how relevant it was that the P-51 could outroll the Me 262. I would like to know if there were not only Me262s falling victim to P-51s and other allied fighters while starting or landing, but also during mid-air fight. Once I read that when Me 262 and P-51 met in such a situation, the result was a stalemate: The Stormbird could climb away and the Mustang could roll away when attacked. It would be most interesting for me if patrolling P-51s over the bomber streams still could (maybe partially) protect them from Me 262 attacks - just by diving down on them and reaching "jet speed".

Another interesting question to you all is if you would have preferred to employ the Heinkel He 280 to the Me 262. The He 280 had straight wings and was able to outroll the FW 190!

And how do you believe the F-80 "Shooting Star" would have involved in the fights? In April 1945 it was already lurking in Italy, equipped with jet engines of a power Germany could not produce (so much to "German technological superiority" in 1945) and beating the Me 262 by 95 km/h, thus flying nearly sonic speed! (Optionally choose the Gotha Go 229 flying wing as the F-80s´s opponent)
The F-80 had straight wings. Only problem ist that over Korea the F-80 needed top-cover delivered by the F-86 with swept wings - but this is a different war!

[GregP]

You are correct in what you said. The Me-262 could and DID run away from the Mustang in combat ... unless it had problems with an engine, which it frequently did. So, Yes, Me-262s were shot down by Mustangs and, Yes, Mustangs were shot down by Me-262s. The main point here is most aerial combat victims are shot down without ever seeing their attacker. That is, they are surprised.

In such encounters, roll and turn rates are unimportant since most of the hits happen before the victim realizes he is being attacked. I'd say MOST of the Me-262s that were shot down outside of the takeoff and landing patterns were gotten by surprise. Ditto for the Mustangs .. in reverse.

That is, if the Mustang pilot SAW the Me-262, then he could handle it. If not, bye-bye P-51.

In a straight dogfight when both pilots KNEW the other one is there and is attacking, they could just barely manage to engage each other for a very short time since the 262 was so much faster than the prop fighters. In combat at the time, I would probably have chosen the He-280 for better maneuverability while still retaining a speed advantage over the Mustang .. or any OTHER prop fighter of the day.

The P-51D has a wing loading of 49.4 pounds per square foot. the Me-262 has a wing loading of 60.3 pounds per square foot. The He-280 has a wing loading of 41.0 pounds per square foot. The Lockheed P-80 has a wing loading of 61.0 pounds per square foot.

All these are at normal takeoff weight and get better as fuel burns off. Ammo is not expended until combat, so fuel is the only weight factor until they join.

So ... the He-280 has lighter loading than the P-51D (!) while the P-80 and the Me-262 are right about even at about 20% to 30% higher. The 262 had 4 x 30 mm cannons and the P-80 (and P-51D) had 6 x 12.7 mm MG. I give the armament edge to the 262. The He-280 had 3 x 20 mm Cannons.

Given the above, we must look at speed. The P-51D could make 437 mph. The He-280 could make 544 mph. The Me-262 could make 541 mph. The P-80 could make 558 mph.

Looking at the data, it doesn't make any difference which jet you choose as far as speed goes. They are all faster than the P-51 by 100 mph or more. Curiously, the He-280 has just about the same speed as the Me-262, even with straight wings. Given the conditions in WWII, I'd chose the He-280 since it had a lower wing loading, could roll better and turn better than either of the two alternative jets, while still being faster than the P-51D. The 3 20 mm cannons hit harder than the 6 50-cal MG of the Mustang ... maybe.

I'd consult tennmike here about the total hitting power. But 3 x 20's seem like apowerful hit if the shells happen to interceopt your flight path.

But ... if I had to fly 500 miles, fight the bad guys, and then fly 500 miles home, I'd take the P-51 since the jets would run out of fuel well before I got home! ALso, I'm not sure most or even any of the early jets would FLY 1000 miles and engage in combat along the way without an engine failure! Once you were down to a single engine on either German jet, you were toast since the P-51 could then catch you and outclimb you. Whether or not it could outmaneuver the He-280 is open to debate, but even the He-280 would be in bad trouble with only half power.

So, I think that while the Me-262 was an excellent early jet, so was the He-280. And the He-280 could roll faster and turn tighter than the Messerschmitt. So, the RLM probably made a mistake in choosing the Me-262 over the He-280 at the time, just as the He-112 was probably a better plane, developmentally, than the Bf 109 ... but that's another argument!

[simon]

I read an article recently, which I'll e-mail you with some more details on personally, but basically the tactics as I understand it were that the Bomber formations had 3 levels of protection. A Close Escort, a High Escort and a more or less free-ranging sweep which patrolled ahead of and higher than the bomber formation. The idea was that any intercepting fighters would have to climb to the bomber's altitude and head toward them, at which point they would get hit by the free-ranging patrol. Any that managed to fight there way past the free-ranging patrol would be bounced by the high escort, and if any still got through the high escort, they would face the guns of the formation and the close escort.

I mention this because basically for the most part what you have is aircraft going head to head. What the P-51 pilots found was that the speed advantage of the Me262 was negligable in combat even at the only true dogfight stage, where the interceptors met the free-ranging fighters, since the closing speeds were huge, even if facing Fw190s and Bf109s, however the .50 calibur Brownings had a higher rate of fire than the Mk108s so they were far more likely to score hits than the German planes, after the first pass and having reached a speed approximately equal to the Me262's in the dive, they could roll, turn and be on the German plane's tail with enough time and speed for another short burst if they hadn't downed it on the first pass.

If by this point either of the Me262's engines had been damaged or had failed the Jet was in real trouble as it could no longer outrun or out-turn the P-51.

I think for both the Gotha/Horten 229, and the Me262 in aerial combat with other fighters, which incidently I would include the Meteor F.8s (Greatly superior to the MkI and MkIII), both German jets would be in trouble because of their armament. The 30mm Mk108s had a slow rate of fire and a slow muzzle velocity making it difficult to aim and hit a target as small as any Allied fighter, whereas the P-80s and later Meteors had far better dogfighting weapons with the .50 cal Browning and 20mm Hispanos respectively, especially as these fighters also increasingly were equipped with the Gyroscopic Gunsight.

Certainly the weight/second of fire of the Me262 will be heavier, but the actual characteristics of the weapons make them significantly less useful, unless your target is a nice big B-17...

OK I know I'm straying onto guns again, I'll stop it! :D

I'd also like to pick up on something that Greg said, certainly the He280 was supposed to be an excellent plane, but the RLM never really chose the Me262 over it. Both were persued as basically private ventures and completely independantly of oneanother, but at the the time the He280 prototypes were flying there was really no requirement for it, once the Me262 prototypes got into the air there was a bit more of a need for a fast, heavily armed aircraft, although don't forget that Hitler famously saw this as the fast "Blitz Bomber", if he hadn't seen any need for a fast light bomber, the whole project may have be shelved and faded to obscurity as just another Luftwaffe Secret Project that never was...

[GregP]

Nice post Simon. I had read the part about the 3-tiered escort, but was addressing one-on-one fighter vs. fighter combat.

If two fighters, a P-51D and a German jet (262 or 280) met with equal starting positions, and if both pilots SAW each other and were going to fight for short while, the plane to be in was the jet. It could dive at the outset to gain speed, zoom above the P-51, accelerate to its optimum speed and do slashing dive attacks as it saw fit until it ran out of fuel or ammo, or decided to leave while there was still enough fuelk to get home and land.

Once out of fuel, the plane to be in was the P-51 since it was probably still running on all cylinders and could catch a gliding Me-262 or He-280. It could CERTAINLY out-climb the opposition!

If either pilot saw the other one first, I'd give the edge to the pilot with better eyes, assuming decent pilots in both planes.

If you had to fly ESCORT to get there and THEN fight, I'd take the P-51D; it could DO it and neither jet could.

Simon, correct me if I'm wrong, but you are talking about P-51s jumping a German jet as it attacks a mass bomber formation. I agree with everything you said about that scenario. About the armament question, I defer to you since I am an aircraft nut, not an aircraft gun nut. However, I HAVE read that the 262 guns has a low muzzle velocity and a slow rate of fire ... fine for attacking big, slow bombers, but less than wonderful for fighter vs. fighter combat.

Still, I'd choose the He-280 for it's better roll rate, lower wing loading, and tighter turning circle as a result of the low wing loading. The tighter turning circle part comes into play as the jets slow down and the g-available comes into play.

I'll do an analysis of the turning radius at, say, 6 g's and post later ... but the more maneuverable jet was still the better choice in fighter vs. fighter combat.

[GregP]

OK, the max speed for the Me-262 was 870 kph (241.57 m/s). The max sped for the He-280 was 875 kph (243.06 m/s). The max speed for the P-51D was 7080 kph (196.67 m/s).

Centripetal acceleration is equal to (V^2/r), where V is velocity in m/s and r is the radius of the circle in meters.

One "g" is 9.78 m/s^2, so 6g is 58.8 m/s^2.

If all these planes cornered at max speed, the He280 would pull 6g's in a turn with radius 1004.7 m, the Me-262 in a turn of radius 993.2 m, and the P-51 in a turn of radius 657.8 m, making the P-51D the turning king of the bunch.

However, none of these planes could sustain a 6g turn at max speed, so the speed would start to decay quickly. Once they are at equivalent speeds, the radius of turn for a given g-force is equal.

The He-280 has the edge here with the lowest wing loading, and the Me-262 would probably stall before it got as slow as either of the other two could. Early jets however, did NOT want to get slow since their acceleration was not good due to poor trhust-to-weight ratio. Compared with either German jet, the P-51D was WAY better when it came to acceleration.

So, the two jets would not elect to turn any further than the amount that cost them 40 or 50 kph of airspeed. Why continue when "speed is life" in an early jet?

So either the He-280 or the Me-262 would be about equally maneuverable (or unmaneuverable as the case may be) if at similar speeds. The lower wing loading of the He-280 would only come into play when it slowed down and, as we have established, that was NOT the object of the WWII German jet pilot. The object was to stay fast, zoom above the opponent, and make diving attacks after which he would zoom back up above the opponent.

If the two jts were high enough to accelerate very much on the way to attack, then the Me-262 would be better since it had a hiugher limiting Mach number due to swept wings. If they were NOT high enough to get into "Mach tuck" on the way down durign an attack, then the He-280 was better since it could climb better, roll better, and was more maneuverable if it DID happen to get slow.

[GregP]

Simon, here's alink to an English translation of the He-280 rejection letter from the RLM.

http://translate.google.com/translate?hl=en&sl=de&u=http://www.maiks-imperium.de/H_280_Dokus/he_280_dokus.htm&prev=/search%3Fq%3Dheinkel%2Bhe-280%26start%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN%26as_qdr%3Dall

Hope it works!

[Corsarius]

Simon, are you taking into account that the Me-262 had leading edge slats for added manoeverability? This wingplan was (more or less) adopted into the F-86 sabre, especially the later marques for added manoerverability.

I would have to say, though, that if it were a Heinkel war rather than a Messerschmitt war, then things may well have gone a different way for the luftwaffe at least. I really do like those Heinkel designs!

And why didn't I get an email, huh?

[GregP]

OK Corsairius,

What IS your email?

[tenmmike]

greg the abov link gives a 404 error

[simon]

Eek! So many replies to deal with at once!

Right, I'll deal with these one at a time. Yes I was referring to a Me262 attack on a Bomber formation, however I was deliberately picking the furthest point out since the US fighters and Luftwaffe fighters would meet on roughly equal terms here and the engagement would be fighter vs fighter.

Corsarius, I did send an e-mail, I didn't get a message to say it had bounced so naturally assumed it had got through, but in summary I'd been on Jury Service for a fortnight recently. I'll try again later from home.

I hadn't particularly taken anything into account appart from what I'd read in a magazine article which was the experiences of a US fighter unit who scored the second highest number of Me262 Kills, so it seemed to work for them, slats, slots or otherwise!

One other thing to mention again regarding the armament, the Me262s Mk108s also were prone to jamming and had a maximum of 9 seconds worth of fire, meaning the Schwalbe pilot had to be pretty sure of his shot to risk wasting the precious ammunition or risking a stoppage, the P-51D pilot had 26 seconds of gunfire with weapons that were not generally prone to jam, he could take a few chancey shots because he had the ammunition capacity to back this up and didn't have to worry overly about stoppages.

[simon]

Sorry, to continue my post, yes I do agree with Corsarius about the issue of a "Heinkel War". Heinkel were persuing a long range strategic bomber (Basically looked like a beefed up He111H with 4 engines!) which has since gained the nickname of the "Ural Bomber" since many people believe it could have made the Soviet position untenable in the latter stages of Barbarossa by hitting the relocated factories beyond the Urals from high altitude and probably nearly immune to interception for the MiG-3 and Yak-1 fighters.

Add this to the very capable although expensive He112 and He100 fighters, and the He280... That would be a good "What if..." to wargame, equip a 1939 Luftwaffe with largely Heinkel types instead of Messerschmitts and see what happens!

[Romantic Technofreak]

I would like to know from you if the discussion how to fight the allied day bombing is possibly to be brought to a conclusion. First, I think, the Mustangs should be attacked separately from the bombers, already shortly after passing the coast, so that they have to drop their external fuel tanks too early and have to leave the bombers alone (a proposal Galland made). For this, you need a fast and maneuverable fighter with a bunch of medium machine-guns like the Mustang has. Maybe the best types for this were further developments of the Reggiane Re. 2005, the Heinkel He 112, or, as jet solution, the He 280.
Second, the unprotected bombers are to be attacked, and for this you best use heavy armed twin-engined fighters, He 280 with 3cm cannons or Me 262 (had it gone into service if the He 280 would be already operational).
And third, there still could be an effect by night attacks on the English airfields. This eventually happened until it was prohibited by General Jeschonnek as "too costly" (not that the losses were too high, Jeschonnek wanted to save resources for the war in the east)!

[simon]

Yeah, OK I'll go along with most of what you say, with a couple of notes. Against the Mustang forcing them to drop their tanks was not always a great deal of use, since once they'd reached the Dutch coast they'd already saved 300 - 400 miles of fuel anyway, and had plenty in their internal tanks unless it was a really long range raid.

As for the possibility of attacks on English airfields, again, yes, but I will say again the only way to stop the US bomber offensive would have been to hurt it on the production lines, and that just was never going to happen, plus even during the Battle of Britain the Luftwaffe proved completely incapable of destroying the British aircraft industry, so I don't really see pin-prick raids against individual airfields having too much effect.

I can see the merit in what you suggest, but don't forget to force all the US escorts to drop tanks your first wave is going to have to fight its way through three layers of fighter escorts, actually engaging them to persuade them they weren't decoys, and even then the fighters are still likely to have ample internal fuel to complete their mission, and possibly strafe the forward airbases of your dogfight fighters which have landed and are refuelling on their way home.

[Romantic Technofreak]

I see what you mean, Simon. And there is another thing: if you attack the bomber stream (right expression?) too early, it might have additional cover by Thunderbolts and Spitfires, even the Mustangs can just appear on the scene when the Dutch coast is already crossed and the other fighters can return home. I think in fact that really happened?!
So, it is not only a quality, but also a quantity problem. To solve this, predictory abilities would have been required... . It is also a hard thing to make a good approach if you have no onboard radar. Many German pilots never found the enemy, they were only consuming fuel!

I also agree with you that it is not possible to destroy the aircraft industry. In Germany the same thing happened, because you can destroy buildings and kill workers, but you cannot destroy machine tools (maybe unless you hit one directly with a 500kg bomb). So, after bombing of the Messerschmitt works, the production lines were transferred to the forests near-by, and production continued... .

But it is still a riddle for me how you can protect a bomber stream by close fighter support, as you mention. During the Battle of Britain, the German fighter pilots wanted to float freely, while the bomber pilots claimed them to stay close to them. Although the fighter pilots protested, Göring ordered them to stay with the bombers, and the bomber losses eventually became less... !
I wonder how this can be, because, as the German fighter pilots stated (for me correctly), it makes no sense to nail the fighter at the bomber´s tailfin. It looses its speed superiority by this measure and is not able to pursue attacking enemy fighters.

Before you said that, I also did not know that the Americans also provided close fighter support to their bombers. I never saw a picture showing this. If you can see American bombers and fighters on one picture, the fighters are cruising high above the bombers. I remeber only one exception: A Lightning seeking cover from the bombers because of engine hazard (the Allisons, you know...)!

[simon]

I think the US tactics worked because they had the distant and high escort as well, as I understand it the close escort worked by physically putting themselves inbetween the bombers and the attacking fighters and firing at the on the way into the formation.

The Luftwaffe in the Battle of Britain did not have the luxury of the distant and high escort, they were tied to the bombers to boost the crew's morale, although this also forced the fighters to fly at an inefficient speeed further lowering their combat radius. As to the bomber losses eventually becoming less I think this may have been more because at the point the order came into force Fighter Command was nearly exhausted, plus the Luftwaffe increasingly moved to bombing at night where the RAF had great difficulty intercepting them.

How would I intercept a bomber formation? It's difficult I admit, but where possible I think the best method would be to form the intercepting fighters up en-masse with a mix of bomber-destroyers and fighters and attack the formation together.

The advantages of this are that you're concentrating on the decisive point, the bomber formation, you're also hopefully going to swamp the escorts so more of your interceptors can make it through to the bombers, also the effectiveness of the bomber's defensive fire is lessened by the overwhelming number of targets each gunner has to choose between.

The disadvantages are that by the time you've formed up your large formation the enemy bombers could have already dropped their bombs, hit their target and be on their way home, so this method would rely largely on a certain amount of precognition, guesswork and prediction and an excellent command and control system which the Luftwaffe did not have.