Wasn't the P-51 the best escort fighter of the war? (1 Viewer)

[Shortround6]

Reason(s) for not using increased fuel tankage from 1940 on is well known - it was then-current doctrine of the RAF. That myopically stipulated the long-range fighter will always be inferior to a short-rage enemy fighter, without looking at big picture.

That myopic view wasn't as far off as you seem to think in 1940-41.

The US bombers weren't there in usable numbers.
The British bombers, for daylight bombing, had some serious issues.
The British were just figuring out the possibility of 100/130 fuel.

The British bombers in 1940-41 are going to flying lower and slower than the US bombers did in 1942-43 making them a much better target for flak, (which was less numerous and had less radar in 1940-42). It took quite while for the British to get up to 15lbs boost on the Merlin 45 or 14/16lbs boost on the Merlin XX series. So escort Spit (or British plane X) is using a Merlin that maxes out at 12lbs or less? Granted the Germans had some trouble using higher than 1.3 Ata boost but the British may not have known that or when it would be fixed.
The 109F-4 shows up in the summer of 1941. Spit V with 25-30 gallons of extra fuel (inside) plus drop tank running 12lb boost vs the F-4 at 1.42 ata? escorting Wellingtons?
Not a pretty picture.

 

[PAT303]

Reason(s) for not using increased fuel tankage from 1940 on is well known - it was then-current doctrine of the RAF. That myopically stipulated the long-range fighter will always be inferior to a short-rage enemy fighter, without looking at big picture.
This is also why I've mentioned just 45 and 90 imp gal drop tanks + 84 gal of internal fuel - those were standard for 1943 Spitfire IX.

Hard to understand the logic behind that to be honest.

 

[PAT303]

The 109F-4 shows up in the summer of 1941. Spit V with 25-30 gallons of extra fuel (inside) plus drop tank running 12lb boost vs the F-4 at 1.42 ata? escorting Wellingtons?
Not a pretty picture.

The rear 30G would be gone by the channel and the extra fuel allowed them to run at higher cruise speeds, at least they would be doing something useful in '41 instead of being squandered in pointless rhubarbs.

 

[pbehn]

The rear 30G would be gone by the channel and the extra fuel allowed them to run at higher cruise speeds, at least they would be doing something useful in '41 instead of being squandered in pointless rhubarbs.

Its hard to imagine anything that could be useful in 1941 most of what could be reached was of no interest to the Germans.

 

[tomo pauk]

That myopic view wasn't as far off as you seem to think in 1940-41.

The US bombers weren't there in usable numbers.
The British bombers, for daylight bombing, had some serious issues.
The British were just figuring out the possibility of 100/130 fuel.

The British bombers in 1940-41 are going to flying lower and slower than the US bombers did in 1942-43 making them a much better target for flak, (which was less numerous and had less radar in 1940-42). It took quite while for the British to get up to 15lbs boost on the Merlin 45 or 14/16lbs boost on the Merlin XX series. So escort Spit (or British plane X) is using a Merlin that maxes out at 12lbs or less?

British bombers in 1941 have had even greater issues in night bombing. It was tough for them to bomb the correct county, let alone correct building (that might be a factory, or might not be).
'Hooker's' Merlin running at altitude and at +12 psi boost/3000 rpm is doing ~1250 HP at ~15500 ft. I don't fancy going lower unless diving to a kill, and then zoom back. In 1941-1942, the 100/130 grade fuel will not help a single jota beyond 15000 ft vs. what will 100/120? grade provided.
Unfortunately, the myopic doctrine persisted until mid-1944.

Granted the Germans had some trouble using higher than 1.3 Ata boost but the British may not have known that or when it would be fixed.
The 109F-4 shows up in the summer of 1941. Spit V with 25-30 gallons of extra fuel (inside) plus drop tank running 12lb boost vs the F-4 at 1.42 ata? escorting Wellingtons?
Not a pretty picture.

The 109F-4 was rated for 2700 rpm and 1.42 ata from winter of 1941/42. Granted, the British are in no position to actually pinpoint exact rpm/boost/HP of particular engine Germans were using, but they know for certain that Luftwaffe can't be in huge numbers in all 3 theaters of war from late June 1941 on - thus my remark on failure to see the big picture.

 

[tomo pauk]

Its hard to imagine anything that could be useful in 1941 most of what could be reached was of no interest to the Germans.

Care to elaborate?

 

[pbehn]

Care to elaborate?

The things that were within reach of UK bombers with fighter escort were mainly French farms, very little that the Germans felt obliged to defend.

 

[tomo pauk]

The things that were within reach of UK bombers with fighter escort were mainly French farms, very little that the Germans felt obliged to defend.

Range of Wellington I (powered by totally non-sexy Pegasus engines) was 1800 miles with 2750 lbs of bombs. Hampden (same engines) was rated for 2000 lbs over 1820 miles. There is 300 miles between Kent and East Englia to the eastern boundary of Ruhr, that was home of a lot of factories the Luftwaffe will be keen to defend.
Wellingtons with Hercules and Whitley were better than Hampden and Wellington Is.
Data sheets kindly provided by Neil Stirling:

 

[Greyman]

Do you know were the p47 and p38 included in that test. From what ive read of pilot accounts the p47 was a real standout when it came to zoom climb.

Can't really find anything on the Lightning but the earlier Thunderbolt (P-47C) was said to be similar to the Spitfire IX. So a little bit worse than the Mustang III. I'd imagine a P-47D with a different prop and water injection would be a whole different animal.

 

[Navalwarrior]

That is the primary reason the USN wasn't concerned about relatively short combat radius of F4U/F6F based on return distance after ejecting external tanks.

For the same reasons, the F4U/F6F weren't much use as primary escort in ETO/MTO/CBI or SWP for escort of long range land based bombers beyond 300mi.

Resp:
Ditto for the FAA use of the F4U/F6F in taking out Turpitz . . carrier launched.

 

[Kevin J]

That myopic view wasn't as far off as you seem to think in 1940-41.

The US bombers weren't there in usable numbers.
The British bombers, for daylight bombing, had some serious issues.
The British were just figuring out the possibility of 100/130 fuel.

The British bombers in 1940-41 are going to flying lower and slower than the US bombers did in 1942-43 making them a much better target for flak, (which was less numerous and had less radar in 1940-42). It took quite while for the British to get up to 15lbs boost on the Merlin 45 or 14/16lbs boost on the Merlin XX series. So escort Spit (or British plane X) is using a Merlin that maxes out at 12lbs or less? Granted the Germans had some trouble using higher than 1.3 Ata boost but the British may not have known that or when it would be fixed.
The 109F-4 shows up in the summer of 1941. Spit V with 25-30 gallons of extra fuel (inside) plus drop tank running 12lb boost vs the F-4 at 1.42 ata? escorting Wellingtons?
Not a pretty picture.

Easy meat for the Me 110 too, when the 45/90 IG slipper tank fails to detach itself properly. It was safer to use the 30 IG slipper which was a combat tank, so only about 130 miles combat radius in 1941 on the Vb, perhaps, 150 miles in 1942 on the Vc/IXc with 45 IG ST and 270 miles on the VII/VIII in 1943 with the 90 IG ST. Its not going to get you to the Ruhr and back. By 1944, you have Mustangs, so who cares.

 

[PAT303]

Easy meat for the Me 110 too, when the 45/90 IG slipper tank fails to detach itself properly. It was safer to use the 30 IG slipper which was a combat tank, so only about 130 miles combat radius in 1941 on the Vb, perhaps, 150 miles in 1942 on the Vc/IXc with 45 IG ST and 270 miles on the VII/VIII in 1943 with the 90 IG ST. Its not going to get you to the Ruhr and back. By 1944, you have Mustangs, so who cares.

Your missing the point, there is no need for slippers, none at all, by '41 the Spit could have 135G internal fuel plus 50G DT so no loss of performance due to drag once the DT is dropped.

 

[Shortround6]

Your missing the point, there is no need for slippers, none at all, by '41 the Spit could have 135G internal fuel plus 50G DT so no loss of performance due to drag once the DT is dropped.

Ok guys, the British had tried it.

M IIA. Several squadrons had examples (Nos 66,118, and 152) , I don't think any squadron was fully equipped but could be wrong. The planes had metal ailerons. and handled better than a trial MK I with single fixed tank and fabric covered-ailerons.

There was a loss of performance. A bit more loss of speed than they estimated (24mph at 15,000ft and31mph at 20,000ft, which can be solved, mostly, but putting the fuel inside) but it was the loss of climb that hurt. Note that loss of climb does not go away by putting the fuel inside, or at least not most of it.

Planes had Merlin XII engines. it was a 40 imp gallon tank. Gross weight went up 341lbs between the two test planes.

Height........time to climb W/O tank................time to climb W tank...........rate of climb W/O tank...........rate of climb W tank...
2,000ft.......................0m 42s.............................................0m 56s....................................2,925................................................2,240
5,000ft.......................1m 42s.............................................2m 12s.....................................2,925...............................................2,240
10,000ft.....................3m 24s.............................................4m 30s....................................2,925................................................2,240
15,000ft.....................5m 0s................................................6m 48s....................................2,770................................................1,990
20,000ft.....................7m 0s................................................9m 48s...................................2,175..................................................1,420
25,000ft.....................9m 36s..............................................14m 6s...................................1,600..................................................1,050
30,000ft...................13m 42s..............................................20m 18s..................................995.....................................................545

Pages 136 and 137 of "The Spitfire Story" by Alfred Price.
Granted two different serial number aircraft do not perform identically.

As for the Spitfire MK V, I forgot the ability to use higher pressures fell off with altitude. While one MK V held 9lbs to justover 20,000ft in the climb with snow guard removed a Later MK V was only able to hold 16lbs to 8,800ft while climbing and dropped to 12lbs of boost somewhere around 13,000ft and then down to 9lbs of boost at about 17,000ft.

when trying to perform top cover for bombers the Merlin 45 is not going to provide the extra power someof us thought it would using higher boost pressures because the Merlin 45 can't supply those pressures at the higher altitudes.

Please remember that climb rate is an indicator of the surplus power available for maneuvering. It is not an absolute measurement. But a plane with a higher climb rate has more tricks u p it's sleeve that one with a lower climb rate, even as a simple as sustaining speed better in a turn.

 

[Kevin J]

Your missing the point, there is no need for slippers, none at all, by '41 the Spit could have 135G internal fuel plus 50G DT so no loss of performance due to drag once the DT is dropped.

In your dreams. Design, development is an evolutionary process. None of you guys here seem to understand that. You design, develop, deliver, look back and think: wasn't that a pile of crap, then you move on, do better.

 

[Shortround6]

Range of Wellington I (powered by totally non-sexy Pegasus engines) was 1800 miles with 2750 lbs of bombs. Hampden (same engines) was rated for 2000 lbs over 1820 miles. There is 300 miles between Kent and East Englia to the eastern boundary of Ruhr, that was home of a lot of factories the Luftwaffe will be keen to defend.
Wellingtons with Hercules and Whitley were better than Hampden and Wellington Is.

Please look at the rest of the data sheets. Cruise speeds of these planes was 155-165mph to get those ranges, and it doesn't matter if they can fly that far. The proposed escort Spit can't come close. Of course neither could a P-51 until it got rear fuselage tanks and bigger than 75 gallon drop tanks.

It was on the "lean into France" campaign that the British figured out you could NOT go potting about the french (or Low countries) countryside at most economical cruise speed without just providing pretty much target practice for the Germans.
So we need the long range spit (1941 version) and much better tactics.
And we need to figure out what the effect range/radius of this 1941/42 Spitfire is. At 20,000ft the MK V could burn anywhere from 88 imp gal an hour (for 368mph true) down to 36 Imp Gal and hour for 263mph true. It might be possible to fly even slower at 20,000ft and burn even less but how slow do you want to go? 300mph true is going to cost 46 imp gal an hour. If you get down low the Merlin 45 will burn 150gal an hour at 16lbs of boost but at that point you are no longer escorting the bombers. You are way too low.

You also need very careful coordination with bombers. Just like the American fighters (of whatever type) and the American bombers one group of fighters is NOT going to fly all the way, not without flying at suicidally low speeds. You need to have relays of fighters coming in to relieve the fighters doing the high speed weave and to relieve the fighters that have dropped external tanks and are running for home on internal fuel laving the bombers behind. anybody what to figure out the chances of 50-100 Hampdens flying over Germany after the Spitfires have had to head for England due to low fuel?
Bombers flying at 10-15,000ft at 165mph are training flights for German flak gunners. flak accuracy depends on several things, one of which is the time of flight for the projectile. Since the projectile covers much more distance in the first few seconds of flight than in the later stages cutting the distance disproportionately increases the AA guns chance of success.

yes the bombers might well accomplish much more flying in daylight but the losses are going to be much higher.

BTW rear upper guns of a Hampden.

Note the sophisticated device to keep the gunner from shooting his own plane.

 

[Navalwarrior]

Please look at the rest of the data sheets. Cruise speeds of these planes was 155-165mph to get those ranges, and it doesn't matter if they can fly that far. The proposed escort Spit can't come close. Of course neither could a P-51 until it got rear fuselage tanks and bigger than 75 gallon drop tanks.

It was on the "lean into France" campaign that the British figured out you could NOT go potting about the french (or Low countries) countryside at most economical cruise speed without just providing pretty much target practice for the Germans.
So we need the long range spit (1941 version) and much better tactics.
And we need to figure out what the effect range/radius of this 1941/42 Spitfire is. At 20,000ft the MK V could burn anywhere from 88 imp gal an hour (for 368mph true) down to 36 Imp Gal and hour for 263mph true. It might be possible to fly even slower at 20,000ft and burn even less but how slow do you want to go? 300mph true is going to cost 46 imp gal an hour. If you get down low the Merlin 45 will burn 150gal an hour at 16lbs of boost but at that point you are no longer escorting the bombers. You are way too low.

You also need very careful coordination with bombers. Just like the American fighters (of whatever type) and the American bombers one group of fighters is NOT going to fly all the way, not without flying at suicidally low speeds. You need to have relays of fighters coming in to relieve the fighters doing the high speed weave and to relieve the fighters that have dropped external tanks and are running for home on internal fuel laving the bombers behind. anybody what to figure out the chances of 50-100 Hampdens flying over Germany after the Spitfires have had to head for England due to low fuel?
Bombers flying at 10-15,000ft at 165mph are training flights for German flak gunners. flak accuracy depends on several things, one of which is the time of flight for the projectile. Since the projectile covers much more distance in the first few seconds of flight than in the later stages cutting the distance disproportionately increases the AA guns chance of success.

yes the bombers might well accomplish much more flying in daylight but the losses are going to be much higher.

BTW rear upper guns of a Hampden.
View attachment 567222

Note the sophisticated device to keep the gunner from shooting his own plane.

Resp:
Good point in the need for relays. The relays also at some point, had fly at an increased speed (remember zigzagging) in order to be able to reach 'interception' speed for Luftwaffe engagement. This aspect used up fuel.

 

[PAT303]

Ok guys, the British had tried it.
View attachment 567194
M IIA. Several squadrons had examples (Nos 66,118, and 152) , I don't think any squadron was fully equipped but could be wrong. The planes had metal ailerons. and handled better than a trial MK I with single fixed tank and fabric covered-ailerons.

There was a loss of performance. A bit more loss of speed than they estimated (24mph at 15,000ft and31mph at 20,000ft, which can be solved, mostly, but putting the fuel inside) but it was the loss of climb that hurt. Note that loss of climb does not go away by putting the fuel inside, or at least not most of it.

Planes had Merlin XII engines. it was a 40 imp gallon tank. Gross weight went up 341lbs between the two test planes.

Height........time to climb W/O tank................time to climb W tank...........rate of climb W/O tank...........rate of climb W tank...
2,000ft.......................0m 42s.............................................0m 56s....................................2,925................................................2,240
5,000ft.......................1m 42s.............................................2m 12s.....................................2,925...............................................2,240
10,000ft.....................3m 24s.............................................4m 30s....................................2,925................................................2,240
15,000ft.....................5m 0s................................................6m 48s....................................2,770................................................1,990
20,000ft.....................7m 0s................................................9m 48s...................................2,175..................................................1,420
25,000ft.....................9m 36s..............................................14m 6s...................................1,600..................................................1,050
30,000ft...................13m 42s..............................................20m 18s..................................995.....................................................545

Pages 136 and 137 of "The Spitfire Story" by Alfred Price.
Granted two different serial number aircraft do not perform identically.

As for the Spitfire MK V, I forgot the ability to use higher pressures fell off with altitude. While one MK V held 9lbs to justover 20,000ft in the climb with snow guard removed a Later MK V was only able to hold 16lbs to 8,800ft while climbing and dropped to 12lbs of boost somewhere around 13,000ft and then down to 9lbs of boost at about 17,000ft.

when trying to perform top cover for bombers the Merlin 45 is not going to provide the extra power someof us thought it would using higher boost pressures because the Merlin 45 can't supply those pressures at the higher altitudes.

Please remember that climb rate is an indicator of the surplus power available for maneuvering. It is not an absolute measurement. But a plane with a higher climb rate has more tricks u p it's sleeve that one with a lower climb rate, even as a simple as sustaining speed better in a turn.

Instead of 40G in that abortion they could have had 30G behind the seat, and that wing tank caused the Spit to be unrecoverable in a spin which is why it was dropped as quickly as it started, as for the loss of climb performance, you don't need climb performance when you have enough fuel to take off and be formed up at altitude before the enemy has crossed the channel instead of having to wait till the last minute and climb like hell.

 

[PAT303]

In your dreams. Design, development is an evolutionary process. None of you guys here seem to understand that. You design, develop, deliver, look back and think: wasn't that a pile of crap, then you move on, do better.

It took the USAF 12 months to recognise the need then design and implement the fitting of drop tanks and rear ''Berlin tanks'' to their P51's, it then took NA just 4 months to have them fitted on the production line plus have retro fit kits for the planes already in service, what was the RAF getting after three years of war?, MkIX's with 85G tanks.

 

[pbehn]

It took the USAF 12 months to recognise the need then design and implement the fitting of drop tanks and rear ''Berlin tanks'' to their P51's, it then took NA just 4 months to have them fitted on the production line plus have retro fit kits for the planes already in service, what was the RAF getting after three years of war?, MkIX's with 85G tanks.

It took the USA until the end of 1943 beginning of 1944 to have a bomber that could be escorted on deep penetration raids in Germany.

 

[Kevin J]

It took the USAF 12 months to recognise the need then design and implement the fitting of drop tanks and rear ''Berlin tanks'' to their P51's, it then took NA just 4 months to have them fitted on the production line plus have retro fit kits for the planes already in service, what was the RAF getting after three years of war?, MkIX's with 85G tanks.

Our priority was fast climbing hard hitting interceptors, not gallivanting over the French countryside hoping some pretty mademoiselle was going to wave at us.