Playing Devils Advocate - Why was the M262 so "advanced"?

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While 18 degrees is not awesome the resultant normal velocity over the wing cross section is Vwing = Vfreestream x Cos alpha

where alpha = 18 and cos 18 = .95

A 5% change to Mcr over the wing is not awesom, but also not trivial. It represents the approximate speed difference between the Me 262 and P-80

This isn't entirely precise for a tapered wing and the formula should be applied to the sweep at the 1/4 chord line.

CORRECTION - There is a 5% reduction in relative velocity over the design airfoil - the resultant aero forces due to the difference in velocity reduction (in the specific case of Lift, Drag Rise and resultant Mcr) may not be precisely 5% due to other factors as Red Admiral pointed out..
 
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No aircraft of that time could have withstood that concentration of firepower.
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No aircraft of any time can withstand that sort of firepower. I am confident that a B2 bomber or F22 fighter hit with 4 x 30mm shells will be in serious trouble.
 

Thanks, yes. That is how I understand it, but thank you for the excellent summarisation. Perhaps I am being harsh but I discounted as being an example of advanced design purely because it was accidental while the theoretical benefits were already known at least in Germany and the USA, if not the UK too.

Parsifal - Granted with the weaponry. A good point, but one I think the Germans would have adopted whatever fighter was put into service. Unless there were technical reasons this could not be done?


Sukhoi certainly adopted the general arrangement used by the 262 (because it worked) but no part of the design was copied from it, much less being tinkered with, it was completely new. Which I guess is just a different way of saying the same thing you did, except that to suggest that Sukhoi 'tinkered' with the 262 to get their own design would be wrong.

The photo of the Meteor you chose is actually a good one, and I was thinking of posting a similar one myself, because although axials are involved, it does not look anything like a 262. This is not only due to the design actually being very different, but also because the nacelles are also quite different to those on the 262. On the Su 9 the nacelles were not only like those of the 262, they were the same nacelles. This 3 view shows how different the Su 9 was, even to the extent that fuselage extends below the wing join as can be seen on the frontal view. The only image in which the Su-9 really looks like a 262 is a photograph of the prototype taken directly from the side.



Sorry if I haven't replied to your own post yet, The wife is nagging for her tea and its my turn to cook, sorry chaps
 
A 5% change to Mcr over the wing is not awesom, but also not trivial.
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It represents the wing presenting 5% less thickness to the oncoming flow, not a 5% reduction in drag or a 5% increase in Mcrit. Might possibly gain a bit in Mcrit but its more dependent on other airframe factors rather than just the wings. How control and stability are affected by increased Mach number etc.
 

It [Cos (Sweep Angle)] IS the relative velocity to the representative aerodynamic shape of the wing - chord wise- as a function of the sweep angle and the free stream velocity... the reason I introduced the 1/4 chord reference is that swept wing design of tapered, trapezoidal wing is classically referenced to the 1/4 chord.

The aerodynamic flow properties (CL and CD) would be analyzed over the projected airfoil with a cross sectional cut perpendicular to the 1/4 chord point - not the wing section parallel to the free stream.

This is also the 'lines' that the aero's and the manufacturing engineers agree for tooling and rib design etc... the resultant 'contour' of the wing as the ribs are installed perpendicular to the spar and sheeted over.

So, if you meant to say that the 5% 'less thickness' is derived by obtaining a new airfoil with a resultant 'longer chord' cut parallel to the aircraft centerline , rather than perpendicular to 1/4 chord - that would not be correct.

You are right about other factors influencing Mcr, but the wings/nacelle bodies in this case are the key factors in Parasite drag for the Me 262.

Having said this - 1. Mcr reduction is not precisely 5%.- .you are correct about this - 2.) the key change introduced by the sweep is the reduction by 5% of relative chord wise velocity reduction over the wing; 3.AR is an important factor and thickness ratio is an important factor - all important during Preliminary design tradeoffs.

For this case thickness ratio is the same, AR is the same and sweep angle is changed from original design.

While the increase in Mcr for the Me 262 is not precisely 1/Cos 18 degrees I stand by this as the primary performance difference between the Me 262 and the P-80 relative to top speed...
 
ME262 advanced? Well it combined most of the newest trend in aviation, each in itself not unique, but the combination was. 1. Jet engines (the first operational a/c to have these) 2. Tricycle gear 3. Swept wings (whatever the reason was they used this_) and a few more. The Jet engines itself made it advanced already, together with the Meteor of course.
 
If I have to get sprayed with that, Gimme the A-10.
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A-10 Thunderbolt II - Wikipedia, the free encyclopedia
The cockpit and parts of the flight-control system are protected by 900 pounds (408 kg) of titanium armor, referred to as a titanium "bathtub". The tub has been tested to withstand strikes from 23 mm cannon fire and some strikes from 57 mm rounds.
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I agree. The pilot is likely to survive and eject after 30mm shells turn the wings and fuselage into swiss cheese. Now where is that rescue helicopter?
 
davebender said:
A-10 Thunderbolt II - Wikipedia, the free encyclopedia


I agree. The pilot is likely to survive and eject after 30mm shells turn the wings and fuselage into swiss cheese. Now where is that rescue helicopter?
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I'm a big fan of surviving. Also the A-10 has been known to lose a surprising amount of itself and fly home so you had better hit it good. If I was the pilot I'd hope to see you or be notified of you a long way off so I can turn my plane and come at you with a burst of my own 30mm. It would be a long shot, but the Gatling has good range.
 

The 'smart' ammo allegedly now has an effective (accurate) range of 5 miles... AFAIK no A-10 has been shot down in Afghanistan (or Iraq) although two were badly damaged but RTB. I am not completely sure of my facts however.

BTW - the Taliban do have the latest Russian portable surface to air missles.
 
When you look at it compared to the allied fighters it was facing then that view is quite clearly correct. I was thinking nore in terms of what it had that nobody else was doing. That may be harsh, but with some of the glowing terms that advanced German tech is discussed in you would expect nothing less. The truth is that it was clearly the best of the initial generation but, if you are looking for something unique there isn't anything. Unlike something like the Me163 which had no equivalent anywhere.
 
Not true....The Me 163 was not unique if you do a quick search on the BOLKHOLVITINOV BI then you will learn of the Soviet rocket fighter.

It could do a supposed 560mph! in 1941!

Frenchman Roland Payen was designing little delta aircraft in the 1930s.

Germans put advanced aircraft into production which other countries did not.
 
Ooh, you bloody nitpickers OK I picked the wrong example (in reality I was thinking only about the Western allies so shouldn't have said 'anywhere', but you understand what I mean, yes?
AFAIK types like the P.1101, Ta183 and Miles M.52 did not have a direct equivalent in other countrues but did have features that became common on future types. Although maybe an oversimplification, that was how I was viewing 'advanced' when I started the thread.

In terms of operational aircraft I readily recognize the Me 262 was the most advanced of those.
 
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The first liquid-fuelled rocket-propelled a/c was a He 112-b prototype modified to accomodate a rocket system designed by Werner von Braun in April, '37. The pilot was Erich Warsitz.

The He 176 was the first pure rocket a/c. Its first flight was on June 20,'39. Again, the pilot was Warsitz.

The Soviet B1 first flew on May 15, '42. The predecessor of the Me 163 was the Lippisch-designed DSF 194, which first flew in the spring of 1940. The Me 163A's first powered flights were in July, '41.

There were earlier flights made by powder-fuel rocket a/c, notably the Opel-Sander Rak.1.

The info is from William Green's, 'Rocket Fighter', Random House, '71.

JL
 
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