davebender
1st Lieutenant
If it was that easy it would have happened historically and there would have been no Mustang designed for British service.
RAF daylight strategic bombing campaign results
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
If it was that easy it would have happened historically and there would have been no Mustang designed for British service.
Shortround6
Major General
The Mustang was NOT designed to be a long range escort. It was designed to be a better P-40. The British Mustangs were NOT designed as an alternative to a long range Spitfire.
For Spitfires the behind the seat tank, aside from photo recon-planes, did not become common ( and even that is stretching things) until the two stage supercharged engines showed up. CG issues may very well have put the kibosh on (stopped) behind the seat tanks on single stage Merlin powered planes.
Ferry use and even photo-recon flights are a lot different than air to air combat flights.
Timing, as always, is everything and while the Mustang was one of the record setters both in shortness of design period and going into production it was still a late comer and the initial factory was in Southern California. Initial delivery's were made by ship through the Panama canal. First Mustangs don't show up in England until the Oct 24th 1941. By the time they are fitted with British guns, radios and equipment and test flown it is Jan 1942. First real (as in more than a handful at a time) operational use was at Dieppe Aug 18th 1942 (British have 4 squadrons, the same number of squadrons equipped with Spitfire MK IXs.)
Using Allison powered Mustangs as escorts is still going to require Spitfires to fly top cover for both the Mustangs and the bombers.
From the article:
It is believed that the transformer and switching station was destroyed, thus depriving the works completely of electrical power. It is known that there is a great shortage of transformers in France and Germany, so much so that they are believed to be virtually irreplaceable under existing conditions. - See more at: Page not found
If true, perhaps these components of the electrical grid could have/should have been given greater emphasis for future raids?
Edgar Brooks
Senior Airman
Too simplistic by far, since there was too much effect on the CoG; the Mark V could only have the tank fitted if the aircraft was using the 170gal ferry tank. Even the Mk.IX generally kept to the same arrangement (e.g. direct deliveries from Gibraltar to Malta.)
In 1944, the Air Ministry wanted to fit the tank in every Spitfire, but the C.O. of 11 Group fought against it (and won,) since it affected manoeuvrability, height and rate of climb, and he had to consider the possibility of combat with jets. The only Mark to have the tank as a permanent feature was the XVI (and that had to have metal-covered elevators and paved runways,) and its use was banned as soon as the war was over.
kool kitty89
Senior Master Sergeant
Or arrange things to get those V-1650-1s going to the P-40F and L ended up in Mustangs instead. Or divert them from american merlins that would otherwise be earmarked for british bombers or Hurricanes.
Not an easy task in terms of politics ... but we're talking hypotheticals here. (one could point to just using british built engines entirely, but that'd make for more of a real logistical mess rather than just a political one -ie shipping airframes without any engines installed)
On the other hand ... if those 9.6:1 V-1710s were out sooner, I wonder if they'd have been considered for possible Merin XX alternatives for bomber applications or the hurricane perhaps. (weaker altitude performance, but maybe good enough to make the improved low RPM, leaner fuel economy be a bigger advantage or close enough of a wash to be more useful as a bomber engine than on fighters)
Hell, with the Hurricane doing plenty of low-alt fighter-bomber work, even the common 8.8 supercharged V-1710s might have made sense to allocate there instead. (free up the pool of Merlin XXs needed for bombers and US V1650-1s for Mustangs, leaving P-40s and Hurricanes with V-1710s)
Come to think of it, with the performance penalty of the sand filters on tropicalized Spits and Hurricanes, both of those types might have fared comparably well with V-1710s. (which seemed to do well enough with the screens already in use for US Army requirements to not need additional bulky filters)
Last edited:
Discussion of long range escorts seems to centre around the world being blind to the obvious. No one believed a long range escort was needed, no one believed a long range escort was possible. Until very late on the US went for more defensive armament on the bombers and eventually special "fighter versions" which carried no bombs at all.
To design a long range fighter in 1939/40 you must predict that they are needed, you must see the speed and economy of the Mustang before it is built and you must have available merlin engines that were produced in 1944. The mustang was a great design by a small manufacturer and had a charmed or even fated existence. Few saw the need of a long distance escort and even fewer saw the Mustang as that aeroplane. If the merlin did not slot in readily where the Allison had been it would never have happened.
To design a long range fighter in 1939/40 you must predict that they are needed, you must see the speed and economy of the Mustang before it is built and you must have available merlin engines that were produced in 1944. The mustang was a great design by a small manufacturer and had a charmed or even fated existence. Few saw the need of a long distance escort and even fewer saw the Mustang as that aeroplane. If the merlin did not slot in readily where the Allison had been it would never have happened.
Shortround6
Major General
The Merlin Mustang prototypes were being worked on before Dieppe or before Mustang was used in full squadron numbers.
Almost 200 Mustngs were built before American Merlins became available in quantity and while fitting a V-1650-1 would be easier than fitting the 2 stage engine it is still not going to be done in a couple of weeks.
You also have the problem of who's engines are you going to use. The American's got 1/3 of initial Packard production and those were the engines that went into American P-40s. The British allocation engines went into bombers and Canadian Hurricanes. Sticking American owned engines into British owned ( bought and paid for) air frames is going to call for a bit of creative negotiations.
Almost 200 Mustngs were built before American Merlins became available in quantity and while fitting a V-1650-1 would be easier than fitting the 2 stage engine it is still not going to be done in a couple of weeks.
You also have the problem of who's engines are you going to use. The American's got 1/3 of initial Packard production and those were the engines that went into American P-40s. The British allocation engines went into bombers and Canadian Hurricanes. Sticking American owned engines into British owned ( bought and paid for) air frames is going to call for a bit of creative negotiations.
I think that as soon as the Mustang was test flown its speed and large internal fuel was appreciated by the test pilots, its poor high altitude performance immediately begged the question "would a merlin fit there" and this was done on both sides of the pond. The P51/Mustang was all about creative negotiations fate and luck.
If Curtiss could manufacture all the P40s the UK wanted =no mustang
If the British insisted on NA making P40s = no Mustang
If the Vulture Sabre worked = need for huge numbers of Merlins = no P51
If the merlin was not able to be developed to circa 1750HP = no P51
If the A36 was not ordered to keep production going probably no P51
A massive amount of luck resulted in a plane that could hardly be designed better for a job it was never actually designed for. It was so good that it is now easy to say the Brits were remiss in not designing one sooner but the Spitfire was designed around a 850HP engine, how would a Mustang/P51 perform with only 850HP?
I'm not sure that Spitfire was designed around the 850 HP engine - the Merlin gave 1000+ from the get-go.
The story of the Mustang would be even a greater delight had the USAF put more emphasis on the XP-51 once it arrived the Wright Field, on Aug 24th. Another XP-51 arrived on December 16th. The 1st tests started on March 1st 1942!!
re. Spitfire V with rear tank - the fuel from that tank can be used up for warming up, take off and initial climb, then switch to drop tank until entering the combat. The difference is that, once drop tank is gone, whole main fuel tankage (84 gals) will be there, vs. the 'normal' Spitfire that will have around 60 gals after dropping the tank. 25 imp gals mean another 20-30 min of cruise, or another 100-150 miles greater combat radius.
The story of the Mustang would be even a greater delight had the USAF put more emphasis on the XP-51 once it arrived the Wright Field, on Aug 24th. Another XP-51 arrived on December 16th. The 1st tests started on March 1st 1942!!
re. Spitfire V with rear tank - the fuel from that tank can be used up for warming up, take off and initial climb, then switch to drop tank until entering the combat. The difference is that, once drop tank is gone, whole main fuel tankage (84 gals) will be there, vs. the 'normal' Spitfire that will have around 60 gals after dropping the tank. 25 imp gals mean another 20-30 min of cruise, or another 100-150 miles greater combat radius.
Last edited:
Easy to get into an argument about nothing of importance here. The Merlin when accepted for service produced 1000HP but even while Spitfires first flight was made, in march 1936 the Merlin was failing tests at that power output.
Merlin E
Similar to C with minor design changes. Passed 50-hour civil test in December 1935 generating a constant 955 horsepower (712 kW) and a maximum rating of 1,045 horsepower (779 kW). Failed military 100-hour test in March 1936. Powered the Supermarine Spitfire prototype.[17]
All engines (especially the Sabre) have massive claimed bench outputs it is a different matter how much they can safely be used at, the merlin II
Merlin G (Merlin II)
Replaced "ramp" cylinder heads with parallel pattern heads (valves parallel to the cylinder) scaled up from the Kestrel engine. 400 Hour flight endurance tests carried out at RAE July 1937; Acceptance test 22 September 1937.[18] It was first widely delivered as the 1,030-horsepower (770 kW) Merlin II in 1938, and production was quickly stepped up.[17]
Work on the Merlin started in 1933 it was in service with 1030HP in 1938 but the Spitfire had to be designed and built around what was known, Supermarine couldnt say to the AM in 1936 it will be a great plane in 1938 when the engine is sorted.
Shortround6
Major General
A Merlin 45 could use 50 gallons an hour at 2400rpm and 3 3/4 lbs boost for 310mph true at 20,000ft.
We have been over this before, and an extra 25-30 gallons of Fuel in a Spitfire MK V might make it possible to "escort" bombers as far as Essen/Dusseldorf. Cologne may be out of reach.
This is hardly a comprehensive bombing campaign and depending on how fast the Germans catch on to the limited target area and concentrate their fighters (and AA guns) to cover it the British have a rather limited time window to do anything.
No hard feelings, I was merely trying to point out that Merlin was delivering considerably more than 850 HP, even on non-military rating.
Thanks - extra 25 gals would then suffice for 155 miles on fairly fast cruise.
Essen/Duesseldorf means Ruhr area, plus the targets from Ruhr to Channel. Should make for a much more comprehensive campaign than wandering around Germany and ocupied W. Europe while not being able to hit anything in a reasonable percentage (not taking anything from the brave crews).
Don't think that removing the LW fighter Flak force away from area west of Rhine in 1941/42 would've been done, unless at the verge of defeat.
- Thread starter
- #54
wiking85
Staff Sergeant
If they could reach the Ruhr they could do some serious damage; Tooze cites the damage done during 1943 to the Ruhr that stopped German armaments expansion. If the British could afford the losses they could really do something significant in 1941-43 during the day against the Ruhr and divert major German aerial power to defend this pressure point.
Shortround6
Major General
And you need the fast cruise to keep from becoming a target.
Not really, the Germans don't have to shift anything from west of the Rhine. Once they figure out that the daylight attacks with escorts can't reach Hamburg, Hanover, Frankfort, Stuttgart, etc air defensed from those areas (and further east) can be moved to the Ruhr area.
Unless the British try for a dual campaign, night and day, but they don't have enough bombers for that.
The disadvantage of the Allison engine of the P-51A (RAF parlance Mustang I roughly) for escort use is moistly a non problem. for the following reasons.
1 The Stirling, Manchester, Lancaster, Halifax and Wellington don't have high altitude engines any better than the Allison apart from maybe the Lancasters two speed Merlin. I'm assuming that RAF mission won't exceed 20,000ft and would generally be less. Hence the Allison engine Mustang has little need to exceed its comfort zone of 15000ft by much.
2 Historically the two stage Merlin 61 engine Spitfire IX(perhaps a little latter), The Me 109G1 and the Mustang I all fly their first service missions around May 1942.
The Germans are dependant on the Me 109F, Me 110F and Fw 190A3 (June 1942 for the A4).
The air distance from London to Berlin (the far side of Germany) is about 550 miles which gives and idea of the missions required. I believe a mission to Berlin would be disasterous for the RAF and it would need to focus on shorter ranged missions say to the Ruhr.
A Spitfire has a range of about on internal fuel of at most 400 miles, with drop tanks released before combat the range is likely to be curtailed to just over 600 suggesting a practical combat escort radius of no more than 250 miles.
The Mustang I P-51A essentially has the same range as the P-51D with tail tank (the Allison is less thirsty) so an RAF daylight mission looks like heavy escorts by spitfires to 250 miles with the Mustang I/P-51A taking over from there.
I would suggest the missions go no deeper than 400 miles. They will be at below 20000ft due to limitations in bomber power plants and to keep the P-51A not too far above its critical altitude. In the 15000-20000 band the P-51 is about as fast as a Me 109G1 and the lower it goes the more the P-51 advantage grows.
Of course long range missions in 1941 with escorts are essentially impossible unless the Spitfire V is properly prepared. The Spitfire carried around 90 Imp gallons of fuel in tanks behind the engine which gave a range of around 400 miles. Historically 2 smaller tanks were fitted in the wing leading edges (4 in all) which increased internal fuel tankage by around 33% and range of some marks of Spitifre VII and VIII by around 50% (600 miles) over the Spitfire IX which lacked it. This suggests to me escort radii with drop tanks of around 400-450 miles. Historically many spitfires also had tail tanks which tended to be regarded as ferry tanks only due to their destabilising effects in combat. However if only 10 gallons (instead of 44-50 gallons) I'm sure the effect would be minimal and further range increases would be possible.
Of course the RAF lacked such a spolicy and Supermarines rang such a program only as a sideline.
1 The Stirling, Manchester, Lancaster, Halifax and Wellington don't have high altitude engines any better than the Allison apart from maybe the Lancasters two speed Merlin. I'm assuming that RAF mission won't exceed 20,000ft and would generally be less. Hence the Allison engine Mustang has little need to exceed its comfort zone of 15000ft by much.
2 Historically the two stage Merlin 61 engine Spitfire IX(perhaps a little latter), The Me 109G1 and the Mustang I all fly their first service missions around May 1942.
The Germans are dependant on the Me 109F, Me 110F and Fw 190A3 (June 1942 for the A4).
The air distance from London to Berlin (the far side of Germany) is about 550 miles which gives and idea of the missions required. I believe a mission to Berlin would be disasterous for the RAF and it would need to focus on shorter ranged missions say to the Ruhr.
A Spitfire has a range of about on internal fuel of at most 400 miles, with drop tanks released before combat the range is likely to be curtailed to just over 600 suggesting a practical combat escort radius of no more than 250 miles.
The Mustang I P-51A essentially has the same range as the P-51D with tail tank (the Allison is less thirsty) so an RAF daylight mission looks like heavy escorts by spitfires to 250 miles with the Mustang I/P-51A taking over from there.
I would suggest the missions go no deeper than 400 miles. They will be at below 20000ft due to limitations in bomber power plants and to keep the P-51A not too far above its critical altitude. In the 15000-20000 band the P-51 is about as fast as a Me 109G1 and the lower it goes the more the P-51 advantage grows.
Of course long range missions in 1941 with escorts are essentially impossible unless the Spitfire V is properly prepared. The Spitfire carried around 90 Imp gallons of fuel in tanks behind the engine which gave a range of around 400 miles. Historically 2 smaller tanks were fitted in the wing leading edges (4 in all) which increased internal fuel tankage by around 33% and range of some marks of Spitifre VII and VIII by around 50% (600 miles) over the Spitfire IX which lacked it. This suggests to me escort radii with drop tanks of around 400-450 miles. Historically many spitfires also had tail tanks which tended to be regarded as ferry tanks only due to their destabilising effects in combat. However if only 10 gallons (instead of 44-50 gallons) I'm sure the effect would be minimal and further range increases would be possible.
Of course the RAF lacked such a spolicy and Supermarines rang such a program only as a sideline.
LW from late June 1941 has a grand total of ~40 (~ forty) Bf 109s in Germany and Denmark.
The P-51A is the Mustang II, it has better altitude capability than Mustang I (the P-51 would be the Mustang Ia - 4 cannons). Problem - the Mustang II will not go in combat before 1943, even if it is produced instead of A-36.
Mustang and two stage Merlinized Spitfire will be too late for 1941 and much of 1942.
Yep, Berlin is way too far for years to come.
That is another problem - the Mustang I does not have drop tanks. Introduced with A-36.
Problem with going too low is that gives the defended the altitude advantage, and even the Flak might interfere.
Leading edge tanks were 2 x 12.5 imp gals, the Spitfire VII and VII have had 120 imp gals total, since one of the fuselage tanks was enlarged, too. The rear fuselage tank of 29 imp gals was used in 1941, albeit just for ferry purposes.
The P-51A is the Mustang II, it has better altitude capability than Mustang I (the P-51 would be the Mustang Ia - 4 cannons). Problem - the Mustang II will not go in combat before 1943, even if it is produced instead of A-36.
Mustang and two stage Merlinized Spitfire will be too late for 1941 and much of 1942.
Yep, Berlin is way too far for years to come.
That is another problem - the Mustang I does not have drop tanks. Introduced with A-36.
Problem with going too low is that gives the defended the altitude advantage, and even the Flak might interfere.
Leading edge tanks were 2 x 12.5 imp gals, the Spitfire VII and VII have had 120 imp gals total, since one of the fuselage tanks was enlarged, too. The rear fuselage tank of 29 imp gals was used in 1941, albeit just for ferry purposes.
Last edited:
Shortround6
Major General
That is the big question.
Could the British mount a big enough campaign, soon enoughand with acceptable losses.
In 1941 production of bombers is a fraction of what it would be later.
For example they built 10 Lancasters in 1941 and 688 in 1942. in 1944 they averaged over 250 Lancasters a month.
It took until June of 1942 to get ten Squadrons equipped with Halifaxes.
As for the Stirling. "Within five months of being introduced, 67 out of the 84 aircraft delivered had been lost to enemy action or written off after crashes." Now maybe there would be fewer crashes in daylight but operating Stirlings in daylight does not sound like the best idea. At their peak of bomber service Stirlings equipped 13 squadrons.
Now you are down to the twin engine aircraft and only the Wellington has any business at all over enemy territory in daylight even with escorts.
Shortround6
Major General
This rather flies in the face of the reality of the BoB. Very few of the German bombers flew at over 20,000ft. Yet British fighters and some German "escorts" often flew at 25-30,000ft. If your escorts are flying at 15-18,000ft they can be bounced from above by what, on the level, would be slower aircraft. The faster climbing 109Fs and Gs can evade upwards compared to the Allison powered P-51s. The faster climbing German aircraft can also easily (at least somewhat) re-position themselves for 2nd and 3rd attacks from above the high performance zone of the Allison Mustangs.
You could use Allison Mustangs for escorts but you better have Spitfires flying top cover in that 25,000ft area. And Spitfire Vs are already in trouble against Late model 109Fs and Early 109Gs without carrying several hundred pounds more in fuel and fuel tank weight.
