What if the Luftwaffe gained air superiority during d-day?

[pbehn]

Good as the Merlin powered Mustang was, hard to see it as THE decisive factor for air superiority during the Normandy landings.

It was the best at what the USA wanted for its strategy. If a "what if" is constructed without the P-51B/C then it must include the USA doing something else, like more and longer ranged P-47s arriving sooner.

 

[z42]

It was the best at what the USA wanted for its strategy. If a "what if" is constructed without the P-51B/C then it must include the USA doing something else, like more and longer ranged P-47s arriving sooner.

Of course. More P-38's and P-47's, with more and bigger drop tanks? Bombing raids only as far as escorts can reach? And, if there's no prospect of a Merlin Mustang, maybe the Americans will develop a 2S2S supercharger for the Allison? If nothing else, kidnap Stanley Hooker and have him design it.

Without the Merlin Mustang, maybe the big week isn't such a success as it historically was. But a failure to the extent that the Germans can achieve air superiority over Normandy? I'm finding it hard to imagine.

 

[pbehn]

Of course. More P-38's and P-47's, with more and bigger drop tanks? Bombing raids only as far as escorts can reach? And, if there's no prospect of a Merlin Mustang, maybe the Americans will develop a 2S2S supercharger for the Allison? If nothing else, kidnap Stanley Hooker and have him design it.

Without the Merlin Mustang, maybe the big week isn't such a success as it historically was. But a failure to the extent that the Germans can achieve air superiority over Normandy? I'm finding it hard to imagine.

Or use a different strategy, remove anything that looks like an airfield with strategic and tactical bombers P-47s, P-51A/ A-36 Typhoon and Spitfires from the Benelux and 150 miles from the French coast.

 

[Shortround6]

Of course. More P-38's and P-47's, with more and bigger drop tanks? Bombing raids only as far as escorts can reach? And, if there's no prospect of a Merlin Mustang, maybe the Americans will develop a 2S2S supercharger for the Allison? If nothing else, kidnap Stanley Hooker and have him design it.

Without the Merlin Mustang, maybe the big week isn't such a success as it historically was. But a failure to the extent that the Germans can achieve air superiority over Normandy? I'm finding it hard to imagine.

The Mustang just edged out the later P-38s in timing. It was only a matter of a few weeks. The Mustang was undoubtedly the better choice. Not only was plane actually better, by spring/summer of 1944 they were making several hundred more per month than P-38s (large, expensive)
However some of the problems with the P-38s that lead to choice (?) may have been self inflicted. It had taken way too long to put a generator on both engines didn't show up until the -10 version. May not have truly solved the cockpit heat problem but went a long way. It also improved chances of getting home on one engine. While most of the systems were hydraulic the props were electric. If the engine with the generator was the one that was lost the pilot needed to exercise very good electric power management to make it home. The pilot was using the battery for all lighting, (instruments), radio, heat and any prop pitch changes.
The -15 series saw the addition of the wing leading edge fuel tanks increasing internal tankage from 300 to 410 gal.
The winter of 1943/44 saw a lot of problems with the P-38 engines due to cold, poor operating technique and a change in the fuel specification/s all combining. The Army's procedure of using high rpm and low boost for cruising not only wasted gas, it over cooled the intake mixture and the engines. If they had used higher boost and lower rpm the turbos would have heated the air more before the air went through the intercoolers and the air would have been warmer through the carb/s and the engine supercharger cutting down on the fuel puddling/mixture settling out problems. Tony LeVier was finishing up his demonstration tour just before D-day which was a little late to solve the problems of Feb/March 1944.
the -25s got the dive recovery flaps from the factory, many earlier P-38Js were refitted in the field.
Not all the P-38s problems were solved and some the fixes took the spring and summer of 1944. But the P-38s and P-47s of the summer of 1944 were not the P-38s and P-47s of Dec 43/Jan 44 either. Not saying that the P-51s were not very important in getting air superiority by June.

 

[NevadaK]

Or use a different strategy, remove anything that looks like an airfield with strategic and tactical bombers P-47s, P-51A/ A-36 Typhoon and Spitfires from the Benelux and 150 miles from the French coast.

I think we would see the air war in the west begin to look more like the air war in the east. Greater emphasis on tactical combat and concentrations of air forces over specific combat areas to gain temporary air superiority.

 

[drgondog]

Can they resume the LR bombing campaign as far as the P-47 escort allows it, like trying to bomb the Ruhr in the stone age for starters?

The arrival of the P-38s in August 1943 (for ops in Oct and Dec 1943) and January for ops in March 1944 - gives good but inadequarte escort deep in Big Week. Suffer greater losses but fewer bomber losses. The 367th which went to 9th AF goes to 8th, bringing Long Range escort to 4 groups.

The attrittion for 8th AF is much higher but the toll on LW will still be significant. I suspect absent P-51B that more P-38 FGs will be pulled from SWP and MTO in January 1944.

 

[EwenS]

The arrival of the P-38s in August 1943 (for ops in Oct and Dec 1943) and January for ops in March 1944 - gives good but inadequarte escort deep in Big Week. Suffer greater losses but fewer bomber losses. The 367th which went to 9th AF goes to 8th, bringing Long Range escort to 4 groups.

The attrittion for 8th AF is much higher but the toll on LW will still be significant. I suspect absent P-51B that more P-38 FGs will be pulled from SWP and MTO in January 1944.

There were not as many P-38s in the SWPA at the end of 1943 as might be imagined. A total of 6 and a bit squadrons worth spread across 4 FG.

5th AF.
8th FG - 80th FS received P-38 in March 1943 but the 35th & 36th FS did not convert to the type until Feb/Mar 1944.
49th FG - In 1943 only the 9th FS was P-38 equipped and it had to give up its P-38 in late 1943 for P-47Ds due to a shortage of the former in theatre. The Group didn't fully re-equip with the P-38 until Sept 1944.
475th FG - fully equipped from formation in Australia in May 1943. The first all P-38 equipped group in the SWPA.
35th FG- the 39th & 41st FS had P-38s during 1943. The last were in the 39th FS which gave up its P-38s for P-47D in late 1943 again due to shortages. The Group consolidated on the P-47D In 1944.

13th AF.
18th FG - 44th FS received P-38 in Oct 1943. 12th FS converted between Nov 1943 & Feb 1944. 70th FS converted in May 1944.
347th FG - 339th FS had P-38 from late 1942. But the other 2 squadrons didn't get them until April & June 1944.

Note all these units were converting to the P-38 in theatre usually from the P-39/P-40.

There were another 2 P-38 squadrons in the CBI by the end of 1943.

 

[PStickney]

Of course. More P-38's and P-47's, with more and bigger drop tanks? Bombing raids only as far as escorts can reach? And, if there's no prospect of a Merlin Mustang, maybe the Americans will develop a 2S2S supercharger for the Allison? If nothing else, kidnap Stanley Hooker and have him design it.

Without the Merlin Mustang, maybe the big week isn't such a success as it historically was. But a failure to the extent that the Germans can achieve air superiority over Normandy? I'm finding it hard to imagine.

There already was a 2 stage (But not 2 speed - the auxiliary stage was run by a variable speed hydraulic coupling, like that of a Daimler-Benz) Allison. It's first operational use was as the engine in the P-63, albeit in that installation, without an intercooler for the best performance. If Packard hadn't been building 2-Stage Merlins, There would probably been more effort placed in the 2-stage Allison (Allison was always short of Engineers, and co-production would have been pursued.
It must be noted that a single aircraft type isn't what achieved Allied Air Superiority. It was the RAF 2 TAF, and the U.S. 8th AF Fighters, Light and Medium Bombers, and USAAF and RAF Photo Recon assets, that found, the German airfields, Supply Dumps., Assembly Areas, road and rail traffic, and shot it down, strafed it, and pounded it flat.
The types is less relevant than the fact that the Allied Air Forces were a swarm of heavily armed hornets hanging up on anything they could hit.

 

[NevadaK]

There already was a 2 stage (But not 2 speed - the auxiliary stage was run by a variable speed hydraulic coupling, like that of a Daimler-Benz) Allison. It's first operational use was as the engine in the P-63, albeit in that installation, without an intercooler for the best performance. If Packard hadn't been building 2-Stage Merlins, There would probably been more effort placed in the 2-stage Allison (Allison was always short of Engineers, and co-production would have been pursued.
It must be noted that a single aircraft type isn't what achieved Allied Air Superiority. It was the RAF 2 TAF, and the U.S. 8th AF Fighters, Light and Medium Bombers, and USAAF and RAF Photo Recon assets, that found, the German airfields, Supply Dumps., Assembly Areas, road and rail traffic, and shot it down, strafed it, and pounded it flat.
The types is less relevant than the fact that the Allied Air Forces were a swarm of heavily armed hornets hanging up on anything they could hit.

Agreed, but if you can't reach it you can't hit it. You end up with aerial combat that looks like eastern front with airfields out of reach of opposing forces and highly dynamic and contested air combat over the ground front. When the 8th AF was able to extend effective fighter coverage throughout the ETO there was no place for the Luftwaffe to seek shelter. The long range fighter was essential for that coverage.

 

[PStickney]

Agreed, but if you can't reach it you can't hit it. You end up with aerial combat that looks like eastern front with airfields out of reach of opposing forces and highly dynamic and contested air combat over the ground front. When the 8th AF was able to extend effective fighter coverage throughout the ETO there was no place for the Luftwaffe to seek shelter. The long range fighter was essential for that coverage.

A 2-stage Allison engined Mustang would have had the same, or better range (The Allison, had a somewhat better Specific Fuel Consumption) and altitude performance as the 2-stage Merlin powered version. There are already 2-stage Allisons in combat - the P-38s. With electronic Turboregulators, Dive Recovery Flaps, hydraulically boosted ailerons, and effective cockpit heating, (In real life, 3 out of 4), they were very effective air-to air fighters. In either case, you end up with what was achieved by the Merlin Mustangs - a fighter that could fly from England to Czechoslovakia, meet the Luftwaffe's fighters once there, and even if they could only flight them to a standstill, still be able to run them out of gas and then fly home.
The basis was there in 1942 - The RAF's Mustang Is were flying Armed Recce missions over Germany, strafing anything interesting, and able to engage or disengage from the Fw 190s that they'd encounter.

 

[tomo pauk]

A 2-stage Allison engined Mustang would have had the same, or better range (The Allison, had a somewhat better Specific Fuel Consumption) and altitude performance as the 2-stage Merlin powered version.

At 27000 ft, with full ram, the best ww2-vintage 2-stage V-1710 (with gear-driven auxiliary stage) seem to be good for 1200 HP; at same altitude, the V-1650-3 and -7 were making between 1470 and 1490 HP. Almost 300 HP of deficit (plus a deficit of having lower exhaust thrust) does not seem to indicate that the altitude performance would've been same as what the Merlin Mustangs were making.
Another problem with the said V-1710 was that it was test flying in the last XP-40Qs in Spring of 1944 in the USA, while the 2-stage Packard Merlins were powering the P-51B, in the UK, 6 months earlier, and were already trashing Luftwaffe by Spring of 1944.
Going with the 1st 2-stage V-1710s, of same generation that P-63A were using, means another 200 HP deficit at high altitudes, and a worse benefit from the ram effect (see the note in the chart), and again lower exhaust thrust. Advantage of using engines of that generation has a benefit of being earlier in service, probably by the time of Big Week? Disadvantage is that a Bf 109G-6 with the fully-rated DB 605A is as fast at high altitudes, and climbs better. Fw 190 should be in the worse position, but the P-51s with the early 2-stage V-1710s would not be in the commanding position as it was the case with Merlin Mustangs.

There are already 2-stage Allisons in combat - the P-38s. With electronic Turboregulators, Dive Recovery Flaps, hydraulically boosted ailerons, and effective cockpit heating, (In real life, 3 out of 4), they were very effective air-to air fighters. In either case, you end up with what was achieved by the Merlin Mustangs - a fighter that could fly from England to Czechoslovakia, meet the Luftwaffe's fighters once there, and even if they could only flight them to a standstill, still be able to run them out of gas and then fly home.

Range was there, effectiveness was not. At least during the Big Week, P-38 force were claiming one-two LW fighters per day.
Merlin Mustangs were not fighting LW to the standstill, but were racking up the scores.

The basis was there in 1942 - The RAF's Mustang Is were flying Armed Recce missions over Germany, strafing anything interesting, and able to engage or disengage from the Fw 190s that they'd encounter.

Armed recon missions above Germany proper - how often were these undertaken by Mustang Is vs. the missions over the occupied Western Europe?