The German arrow!

[GrauGeist]

I think the capability of an aircraft in a dive is often confused. The limiting speed or Mach number is often used, whereas, in fact, it is the acceleration in a dive that counts most.

The Spitfire was proven, by tests, to have a very high Mach number for the day, higher than the P-51 in fact. But the P-51 was considered a better diver because it accelerated in the dive better, pulling away from the Spitfire.

I'd be surprised that the Me 262 didn't have at least as good acceleration in a dive as the P-47. Considering it didn't have the big pprop up front to slow it down.

The only thing I can think of why that would be the case would be the time it takes to accelerate the engines up to full power.

One of the main factors in resisting compressability, is the control surfaces and how they react as they approach that point.

The Me262 tended to "nose down" as it attained Mach .86 and only by pushing forward on the controls (altitude permitting) would the pilot be able to work the '262 free.

The P-47 was exceptionally rugged and could survive such a condition (again, altitude permitting) and there's several accounts where the pilots did this and survived.

Goodson was one such pilot who pushed his P-47 into a terminal dive to try and save a mate from a bounce by a Fw190 and nearly destroyed his Jug in the attempt. Good read, by the way: "Tumult in the Clouds" by James Goodson himself.

 

[GrauGeist]

The AFDU did tactical trials to compare the leading fighters pre D-day, & for diving, concluded that the Tempest had the best
dive/zoom characteristics yet seen by the unit.

Given that up to its lower limiting speed Mach 0.74, the Meteor III could out dive even the Tempest, it seems unlikely
that the much more aero-capable Me 262 wouldn't be even quicker in the dive than the Meteor, let alone a P-47.

Factory directive, the Me262 was not to exceed Mach .86 IAS

 

[GrauGeist]

Which was way higher than the P-47.. & (Mach speed is shown on a Machmeter, FYI)
IAS 'limitations' via the ASI are another matter.

I'd like to know...which Allied aircraft had a "machmeter" installed.

 

[wuzak]

Please refrain from personal insults before the Mods send one or both of you to the naughty corner....

 

[GrauGeist]

Better look it up then, wiki-boy.

ahh...here we go again...

Aircraft of the day had limited instrumentation compared to modern times. So when the Me262 reached 660mph IAS, it had reached Mach .86.

Oh...and don't need wiki, child. Unlike you.

 

[GrauGeist]

Please refrain from personal insults before the Mods send one or both of you to the naughty corner....

It's perhaps getting to that point, sadly enough.

 

[wuzak]

http://www.wwiiaircraftperformance.org/p-47/Naca_TN_2899__F-47D-30_Flight_Test.pdf

Dive Condition (fig. 10) - The airplane failed to meet the requirements in this condition. The data show that the airplane to be unstable with stick free at speeds above 260mph [IAS I assume] and neutral to unstable stick fixed above approximately 300mph. The same condition existed at low and high altitude.

 

[GrauGeist]

http://www.wwiiaircraftperformance.org/p-47/Naca_TN_2899__F-47D-30_Flight_Test.pdf

Dive Condition (fig. 10) - The airplane failed to meet the requirements in this condition. The data show that the airplane to be unstable with stick free at speeds above 260mph [IAS I assume] and neutral to unstable stick fixed above approximately 300mph. The same condition existed at low and high altitude.

I find it interesting where they stated "airplane to be unstable".
Was this model retro-fitted with the fillet?
The -40 series onward saw that as a standard feature but pre -40 series had to have the fillet retro-fitted.

 

[wuzak]

From America's Hundred Thousand:

The 500mph IAS was the dive limit speed (400mph above 25,000 feet), and it was recommended dive recovery be made no lower than 12,000 feet. At this altitude the limit dive speed corresponded to 601mph TAS (true airspeed) and a Mach number of 0.82. At this speed the P-47 was well into compressibility with a drag coefficient two and one half times the value at moderate speeds.

 

[mikewint]

A bit late to this, uh, "discussion" but, as you can clearly see and as Dave has repeatedly stated in flat out speed the 262 can't be touched by either the Tempest or P-51

 

[pbehn]

Ah, OK, Mike, sure, there is no no question about Vmax. but G-G wrote that the Me 262 "could not be caught", & yet, it was.

I am sorry but that is a silly statement, an Me 262 with a full tank of fuel could not be caught, An F22 surrounded by enemy aircraft would have to land eventually.

 

[mikewint]

The 262 suffered from several problems such as poor or nonexistent fuel plus those Jumo engines that lasted only about 10 hours. German industry did not have the required metal to make the turbines properly. Pilots were also at a premium and lack of fuel made training new pilots very difficult. Now we have a new technology which requires the invention of a whole new set of tactics to make the best use of the new weapon. The older pilots were prop-fighter pilots whose reflexes and instincts had to be reprogramed. Its pilots – intrepid men all, for the Me 262 was cantankerous and dangerous to fly – claimed 542 allied warplanes shot down while sustaining just 100 combat losses. Luftwaffe ace Hauptmann (Capt.) Franz Schall was credited with 17 aerial victories, including six four-engine bombers and ten P-51 Mustangs.
Whatever the tactics used, the sheer number of allied planes involved made the jet attacks almost irrelevant. For instance, on March 18th III./JG 7 sent up 37 Me 262s to engage a force of 1,221 American bombers and 632 escorting fighters. This action marked the first time the new R4M rockets were used by the Me 262. In the end 12 bombers and 1 fighter were claimed with the loss of 3 Me 262s. Even on their biggest day, JG 7 flew 38 sorties, knocking down 14 US and British bombers and 2 fighters with a loss of 4 Me 262s. Their best efforts yielded less than a 1% loss for the Allies. Thus, we see the pattern that marked most German efforts in the latter part of the war. The Germans had many effective weapons but they were no match for the overwhelming Allied numerical superiority.
None of the above contradicts Dave's original statement about catching the 262 as it was fully 20 percent faster than the Allied fighters it came up against, capable of reliable performance once it reached operating altitude, highly maneuverable and heavily armed, the Me 262 never overcame obstacles created by poor leadership, technical glitches, and the vicissitudes of war.

 

[GrauGeist]

I stated that an Me262 cannot be caught in level flight at max. or in a climb. Fact.

I already posted reasons that may have contributed to the one being shot down in the guncam footage.

But a fit Me262 versus a fit Tempest provides no contest - the Me262 will leave it in the dust.

 

[wuzak]

I stated that an Me262 cannot be caught in level flight at max. or in a climb. Fact.

I already posted reasons that may have contributed to the one being shot down in the guncam footage.

But a fit Me262 versus a fit Tempest provides no contest - the Me262 will leave it in the dust.

And the claim that the Tempests tracked it for 50 minutes would suggest that all was not well with the Me 262. In normal circumstances the Me 262 would have extended the gap by ~100 miles, which would mean the Tempest pilots would have to have amazing vision to keep tracking it.

If the Me 262 was heading to its home base it surely would have landed and parked up long before the Tempests arrived.

 

[wuzak]

Another factor is that Me 262 JaBos were also flown on ops by ex-bomber pilots, who were likely at a disadvantage in fighter combat scenarios.

Not sure about this.

No doubt that the Luftwaffe were in serious need of pilots late in the war and transferred bomber pilots to the fighter arm.

It was my understanding that the Me 262 squadrons got the more experienced fighter pilots, many of whoom would be termed Experten.

On the other hand, bomber pilots would not have piston-engine fighter habits in combat and may have been easier to mould to the needs of the Me 262.

 

[GrauGeist]

Unlike an Me 262 that tries to evade a P-47 by using dive away tactics, huh?

The fact remains, an Me 262 was chased for 50 miles by Tempests running WOT at low-level,
& was caught, then shot down, biting the "dust" - itself.

An Me262's best defense is to climb away from an adversary, as I've mentioned several times.

And the worst thing any aircraft can do, is try and dive away from a P-47.

 

[GrauGeist]

What's funny about my post #77, dill?

 

[GrauGeist]

Even the P-51 out-dives the P-47, & the Tempest out-dives a P-51..

Source?

 

[wuzak]

Ta W, & that P-47 advisory contrasts with 2nd TAF Tempest SOP, as noted by CO of 486 (NZ) Squadron, Jimmy Sheddan:

"The procedure was to cruise at about 8,000 ft. At that height it was possible to see without being seen,
dive almost vertically - when a speed of ~600 mph would be reached, then after the attack, zoom back
to our original patrol height. The main advantage of the Tempest for this form of attack was its ability to
pick up speed when diving, its steadiness & ease of handling, & its initial zoom climb.
Pull the nose straight up & it fairly rocketed to the 5,000 ft mark, the height where the light flak
began to curl over."

I find that hard to believe.

1. That a Tempest could reach 600mph TAS diving from 8,000ft
2. That a Tempest could do such a dive AND recover from 8,000ft

I think there may have been some exaggeration there.

 

[wuzak]

Even the P-51 out-dives the P-47, & the Tempest out-dives a P-51..

The P-51 out-dives a P-47 in terms of terminal speed, no doubt..

The same would be true of the P-51 vs the Tempest I'm sure.

But my theory is that the acceleration in the dive was more important than terminal speed. That the acceleration in the dive gives separation from a slower accelerating adversary, and when the pilot pulls out of the dive he has very much more energy than the adversary.

That means the pilot has extra speed if he decides to fly level, or his zoom climb will be better.

Another example is the Spitfire vs the P-51. The P-51 was rated far better in the dive than the Spitfire IX as during the initial stages of the dive the P-51 would pull away. But we know that the Spitfire's ultimate dive speed was very high, as a Spitfire XI, the PR version of the IX, was dived to a terminal speed of 606mph (Mach 0.891) - and no, this was not the one where the prop broke off.

Note also that the 600mph dives in a Spitfire started at 340mph and 40,000ft, terminal speed was at around 28,000ft and recovery was at around 20,000ft.