Thunderbolts and Mustangs versus the Jagdwaffe (split topic)

[Franek Grabowski]

Juha
Yes, please, but I do not see any reason why an operational range should be very different.

Ruy
Just a short comment concerning Japanese aircraft - most popular types were Zero and Hayabusa, then perhaps Shoki. They were used through the whole war of 'Pacific'. I consider other types both not significant and not really mature. Problems were not limited to poor quality fuel, though it was doubtless one of the factors.
Going back to Mustang vs T-bolt, one of the principles of aerial tactics is to keep own bases out of reach of enemy forces. Introduction of T-bolt pressed Germans to the Netherlands, then look what was a real impact of Mustang. And the latter was not only better in range.

Artie

1. Allison P-51s: “But by 1944 there were no jigs available and no production run was possible”. I cannot comment on the tooling being destroyed, but the engineering of V-1710 engines in Mustangs continued through the war.

It appeared only in form of XP-51J lightweight Mustang.

IIRC, the final development of the Mustang lineage, the P-82, did have V-1710 engines. Certainly, It was within the capability of WWII US aircraft industry to tool up quite rapidly for production changes. It should also be noted that the P-82 was also a heavier a/c than either the P-51 or P-47 in any version (BTW, a squadron was based near my home in the late 1940s and IMHO they were the most exciting piston fighter ever to see and hear make a low pass).

I am not sure if we can discuss P/F-82 here, it was a quite different aircraft.

2. P-47N: “ This aircraft was specifically designed for the SWP and having increased weight had little chance with lighter German types.” IIRC, by the beginning of 1945, the Eighth Air Force had made the decision to standardize on the P-47N as it’s long range escort fighter and some had been delivered to England in early 1945, but did not make it to squadron service prior to V-E day.

The source please. By the way, if true, was not it due to planned use of 8 AF against Japan?

3. Weight: “Such aircraft like P-47 or B-17 were simply overdimensioned, thus overweighted, thus stronger than comparable designs - performance suffered.” I really believe your opinion on that issue also needs to be questioned. EVERYTHING ELSE BEING EQUAL, it is true that lighter is better! But in the real world of aircraft design almost nothing is equal between two designs (unless they share some major components, like the engines, then they diverge).

Climb speed is approximated to be a proportion of difference of power available and power required to a mass multiplied by gravity. Try to proove me then, that weight is not an important factor in aircraft's performance!
Of course this increasing weight may be compensated by increase of power but this also means increase of engine's weight and fuel consumption. The latter results in loss of range - increase of tanks volume leads again to increase of weight, not only of extra fuel but also of extra tanks and construction around them. This becomes further complicated if dimensions are affected as this results with aerodynamical changes - evolution of P-35 is a very good sample.

This meant tradeoffs in some areas, but from everything I have been able to learn, the P-47 was really a pretty good handling machine and aerodynamically clean for a WWII piston fighter.

T-bolt had significantly lower critical Mach number comparing to Mustang or Spitfire. Not a very good proof of aerodynamic cleanless.

If just being smaller and lighter were the only criteria, then the Caudron 714 should have been the best fighter of WWII, hands down.

Polish pilots who flew Cyclone considered it a very pleasant aircraft, hands down. Cyclone's problems were not in weight itself but in aerodynamics, strenght and armament. Quality and performance is extrapolation of several factors, that is correct. T-bolt with a Cyclone's weight would be doubtless a designer's dream.

IMHO, neither the B-17 or P-47 were overweight, but had very sturdy, easy to maintain airframes that could accept severe combat damage and make it home with crew survival (In a war of attrition, not a performance parameter to be ignored).

While aircraft is designed, maximum loads are calculated and then multiplied by a safety factor. Then the airframe is designed to sustain those gross loads. Most commonly 1,5 factor is used in aviation (for a comparison in cars it is 8 IIRC), but sometimes other, usually higher factors were used, especially in older designs when theory of strength was not so well known. Of course use of higher safety factor results in stronger construction but also greater weigth. Longevity of such designs like DC-3 is a direct result of this approach.
By the way, comparison of bombload of B-17 to other, I would say more matured, 4 engined aircraft like Lancaster or Liberator is not very favourable towards the former. I think there was a wartime song about it.

4. Other participants in this discussion: “Sorry, performance figures are clear, it is just only most authors have no slightest idea what thery are telling about.” My question is; does this statement refer to others who have contributed to this thread? If that was your intent, then I would like to ask, what is your background?

My intent is clear. I just only state that very few of authors of published aircraft monographs have any engineering background, thus more than often their conclusions are wrong and misleading. This leads to such a nonsenses like attributting clipped wings to LF Spitfire variants for example.

Six Nifty .50s

Which performance figures?

All!

Unless the authors personally engaged P-47s in combat, their opinions are unnecessary. Based on their practical experience, several German fighter pilots suggested the Thunderbolt was a more dangerous and troublesome opponent than the Mustang.

I do not see any reason to believe the personal engagement's experience is a decisive factor when discussing those matters. And while we are at German pilots' opinions, by 1944 they believed every aircraft was a US one and not able to distinguish RAF types.

Some enemy pilots assumed that was true of the older Thunderbolt, because of its immense size, but they paid for that mistake with their lives.

Well, it seems not so apparent, when getting through 8 AF narratives.

I will not forget that many people once used the same excuse about German records. Certain Japanese loss reports have survived, and probably these are no less honest than their opponents. Like every other air force, RAAF Spitfire units inflated shootdowns substantially. One figure quoted amounted to about 7:1 overclaiming. I'll look into it more on next trip to the library.

Based on my research concerning Polish losses in WWII, I consider German records highly unreliable, especially as practically only source are GQ6 returns.

One cannot escape common knowledge that liquid-cooling systems were easily knocked out with one bullet or shell splinter.

Never claimed anything different, nonetheless I talked to several Polish 2 TAF Spitfire pilots and I never heard them complaining a lot about the problem. Well, if you have any particular questions, put them here - a good excuse to call one of them by phone.

Another factor is that Spitfires and Merlin Mustangs had persistent structural problems, especially when put into high speed dives. Both planes showed an alarming tendency to shed their wings or tail on pullout. It was an adventure to plug all of the coolant leaks on the P-51B. In 1942, 36 Spitfires were under investigation for structural failures and in 24 cases the tail unit broke off in flight. By 1944, the Spitfire was often used as a fighter-bomber and another hazard was found in that the engine mounting U-frames would buckle in dive pullouts.

IIRC through the whole WWII one Polish pilot was killed due to Spitfire's structural failure, while another was forced to bail out. Both did it 'on their wish'. Indeed several aircraft returned damaged but this was not that very common and more a myth than a problem. Otherwise, Spitfire's design was sturdy enough to allow pilot to return home on a write off - in case of other aircraft pilots had no position to complain, being already 6 feet under.

The A-36 at least had dive brakes to control descent, so these were safer to fly while vertical bombing. But otherwise, I cannot imagine why anyone would want to pilot a Mustang or Spitfire with a ground attack unit.

Due to excellent aerodynamics, Mustang accelerated pretty quickly thus making some trouble in dive bombing but I never claimed it was an excellent ground attack aircraft! More, T-bolt was better, hands down, just only useless as a fighter.
By the way, while we are discussing ground attacks, why not to discuss effectiveness of aerial support in general? It does not look impressive at all.

Well the main interest of Jagdwaffe (B-17s and B-24s) did not dive down to drop bombs from low altitude, so the German response is a relevant point.

Yes, but USAAF considered it is easier to not to allow Germans to climb rather than to escort bombers. Mustang did it possible.

The best part of the Merlin was the 2-stage supercharger attached to it; not the engine itself which was fragile. Main bearings were weak, and the carburettor was worthless until replaced with the American type.

I have never heard pilots complaining on reliabilty of their Merlins but there were several cocnerning Allisons - ORB of 309 Sqn notes frequent visits of Allison engineers trying to rectify experienced problems.
What do you mean by American carburettor?

On average the Allison lasted three times longer before rebuild, even though manifold pressure was often overboosted to about 20 lbs. -- not recommended by the manufacturer, but the engine held together reliably.

What fuel was used?

Note that air racing teams flying P-51Ds installed Allison connecting rods to prevent their Merlins from blowing up. Without this modification, the Mustangs could not compete with the speedy Bearcats at Reno.

Aircraft races are so specific matter, I do not think any experience applies here. Otherwise, I do not have any objection against admitting that some parts were better here rather than there. The fact is that Merlin was most common Allied V-12 engine, however.

Not many air combats took place over towns inside Normandy. The Luftwaffe did not often penetrate the fighter cover surrounding that part of France -- at least not when the sun was shining.

Several managed to the beaches through June 1944 but indeed several more found their fate on the way to. But it does not change the fact all the combats were low level ones.

Besides, the Luftwaffe was short of petrol by the autumn of 1943, so the Focke Wulfs and Messerschmitts usually did not bother with Allied fighter-bombers, medium bombers and their escorts, or other fighter patrols that were not tied to B-17s and B-24s. What little avgas remained on tap was needed for training.

When I used a lack of fuel argument in an another discussion, Don Caldwell gently expressed remarks that fuel deficenties started during or after Normandy Campaign.

It is widely believed by fighter pilots that in tens of thousands of engagements, the overwhelming majority of pilots shot down were hit by gunfire from another pilot who was not seen by the victim. Thus, I would challenge you to identify the number of combats in which a difference in 'maneuverability' made a difference in the outcome.

Indeed most pilots were downed in the first attack but judging by combat reports and other relevant documents of PAF, I would say several downed pilots were awared of danger but simply unable to undertake successfull evasive action.

Regards