8th Air Force use of Mosquitoes

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gjs238

Tech Sergeant
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Mar 26, 2009
Would the 8th Air Force have been better off using Mosquitoes, particularly when operations were suspended due to unsustainable losses?

Were Mosquitoes ever tried or contemplated?
 
Would the 8th Air Force have been better off using Mosquitoes, particularly when operations were suspended due to unsustainable losses?

Were Mosquitoes ever tried or contemplated?

I dont think they could be considered really. Firstly you cant just produce 2000 mosquitos in a few months. The mosquito was great for small precision raids but a massed formation would have been just as vulnerable as a B17. I think both sides missed a chance with the mosquito as a concept. If NAA were asked to design the B 25 without defensive armament and the aerodynamics of a P51 they could have brought something very different to the conflict.
 
An interesting aside the official position of the USAAF was that the Mosquito was unsuitable as a daylight bomber. So they wouldn't have used it anyway.
That I should add was not the view of those who had to fly the aircraft, but the official view. The 8th Airforce normally used the Mosquito for weather recce and/or checking the weather over the targets so the main bomber forces could go for the secondary targets at an earlier stage.
 
There seems to be a rather bigger difference in bomb load than most people acknowledge. The Mosquito could only carry four 500lbs unless fitted with bulged bomb bay doors which allow for a Single 4000lb bomb. The Mosquito could not carry four 1000lb bombs or eight 500lbs or even six 500lbs (unless tow were under wing which tends to cut into the performance somewhat), A rack was developed which allowed six 500lb bombs in the bomb bay it was seldom used or fitted apparently.

While many sources claim the B-17 could only carry 4,000lb to Berlin this actually seems to be an "average" bomb load with 5,000lbs actually being quite common, ten 500lb bombs or five 1000lbs. A number of planes, usually divided by squadrons or groups carried large quantities of incendiary bombs. These bulkier bombs cut the load to just over 3,000lbs per plane and may be the reason for the 4,000lb "average".

The idea that a single Mosquito could do the job of a single B-17 doesn't seem to hold up well. I don't know what ratio of Mosquitoes to B-17s would be needed to get the same bomb tonnage onto target "areas".
 
The U.S. Army Air Corps was ruled by heavy bomber proponents. Any officer who proposed replacing B-17s with light bombers would likely get posted to a weather station in Greenland.

Aside from that, what advantage does the British made Mosquito have over the American made A-26?

Mosquito Mk XVI.
de Havilland Mosquito - Wikipedia, the free encyclopedia
10,700 lbs total payload (max weight less empty weight)
4,000 lbs bomb load.


A-26B.
Douglas A-26 Invader - Wikipedia, the free encyclopedia
12,150 lbs total payload (max weight less empty weight)
4,000 lb bomb bay. An additional 2,000 lbs of bombs or fuel may be carried on wing hardpoints.
 
I have just shown that the Mosquito could NOT do the job of a B-17. If you think it can please post numbers from actual raids or manuals.

See this website for actual operations by B-17s

303rd BGA Combat Missions and Reports

The Mosquito was an amazing aircraft that could do a number of jobs and could perform some bombing missions that a B-17 had no hope of performing, but this notion that that Mosquitoes could have replaced B-17s on anything approaching a 1 for 1 basis needs a complete rethink.

AS for the a Comparison of wiki, entries, it is barely worth looking at except to note how little it actual tells us. In order to truly compare bombers you need to know what bomb load they could carry over what radius at what speed. Comparing max bomb loads or max ranges or max speeds presents way too little of the total picture. as does just listing a maximum weight of bombs. As noted the Mosquito was sort of an either/or aircraft. either 2000lbs inside (four 500lbs) or a single 4,000lb bomb. there was no option to carry 1000 bombs or 1600lb bombs or even eight 250lb bombs.
The B-26 may have limitations also, I don't know what they are at this point but any real discussion of the capabilities needs more than wiki is giving us.
 
It is an interesting concept. At the time that this would have been contemplated (mid 1943) there were, perhaps, 400 BIV Mosquitoes built, some BIXs (92 built in 1943) and a few FBVIs (IIRC production of these started late '42/early '43). The BIV had a maximum bomb load of 2000lb, and I don't believe that they were capable of carrying wing ordinance. The BIX had the strengthened basic wing of the FBVI which allowed the use of external stores/fuel.

The 8thAF didn't have many more B-17s/B-24s than there were Mosquitoes available at that time, but the production rate back home was much higher.

Not sure how many of the BIVs that had been built were in use by the British at that time either. I know of 105 and 139 squadrons, but not sure about any others.

The conversion to use the 4000lb cookie wasn't tested untill later in 1943, and the Avro carrier must have come later than that. I don't believe that the Avro carrier/6 x 500lb combination was ver used in combat, mainly because of the RAF's infatuation with the 4000lb HC bomb.

Using the Mosquito in massed formations like those of the B-17s would have been suicide. The formations used by the 8th AF was all about mutual defensive fire, and was designed to give maximum protection. As the Mosquito was unarmed the formation gave no benefit. The downside was, of course, that B-17s had to fly quite slowly to maintain that formation, and flying the same formation in Mosquitoes would completely negate its own defence - speed.

The other problem with the defensive formation was bombing accuracy. It was quickly determined that for all bombers to bomb accurately it required individual bomb runs. Which required a long straight approach. And presented teh defenders with great targets. The solution, devised by Le May, was for the bombers to remain in formation and bmb on cue from the master bomber. Thus, by definition, the bombs fell over a wide and long area. Essentially carpet bombing.

A Mosquito raid with BIVs would be devised differently. I would not send them all in one go, but in smaller groups, with a few different routes to target. Spread the defensive fighters over a wider area. You could vary the attack method - some could come in high, others in low for improved accuracy.

In a raid as distant as Berlin a Mosquito could fly to target and back twice in the time that it took the B-17s to do their mission and return. That is not inclding the time it tok for the B-17s to form up over England, which could take as much as 2 hours. In that time your Mossies are half way to Berlin.

Now, look at the Schweinfurt mission. There were 80 direct hits on target, 500lb bombs IIRC. So, if you could get 100% accuracy you would need only 20 Mosquitoes. But that is unrealistic. 100 Mosquitoes would require only 20% accuracy, however, and 200 would need only 10%. On the Scweinfurt mission the B-17s carried about 5000lb each, and over 250 of them bombed the target.

If the 8th AF did try using Mosquitoes for bombing, and there was a measure of success, I would think that the A-26 program would have been accelerated - I do believe it was delayed or whatever reason - and they would have been available sooner.
 
I have just shown that the Mosquito could NOT do the job of a B-17. If you think it can please post numbers from actual raids or manuals.

See this website for actual operations by B-17s

303rd BGA Combat Missions and Reports

The Mosquito was an amazing aircraft that could do a number of jobs and could perform some bombing missions that a B-17 had no hope of performing, but this notion that that Mosquitoes could have replaced B-17s on anything approaching a 1 for 1 basis needs a complete rethink.

AS for the a Comparison of wiki, entries, it is barely worth looking at except to note how little it actual tells us. In order to truly compare bombers you need to know what bomb load they could carry over what radius at what speed. Comparing max bomb loads or max ranges or max speeds presents way too little of the total picture. as does just listing a maximum weight of bombs. As noted the Mosquito was sort of an either/or aircraft. either 2000lbs inside (four 500lbs) or a single 4,000lb bomb. there was no option to carry 1000 bombs or 1600lb bombs or even eight 250lb bombs.
The B-26 may have limitations also, I don't know what they are at this point but any real discussion of the capabilities needs more than wiki is giving us.

I believe the Mosquito could carry 2 x 1000lb bombs (and probably 3 x 1000lb bombs) in the standard bomb bay, but the RAF preferred the 500lb or 4000lb HC bombs. With a slight modification to the bomb's tail the Mossie could also have carried 2 x AN Mk1 1600lb SAP bombs internally. But they were American bombs.

A Mosquito could also carry 2 x AP 2000lb Mk1 bombs inside the standard bomb bay. At least, they would fit inside the standard bomb bay.
 
The A-26 had a few problems of it's own as a fast "strategic" bomber. AS built is used single stage, two speed supercharged engines which rather limited it's altitude performance (like 22,000ft service ceiling, operational ceiling is even lower) which puts them in greater danger from flak. While the top speed of 355mph at 15,000ft is impressive it is not cruising speed or bombing speed. It's operating altitude certainly puts into the 190s preferred altitude range.
Maybe it could have copied the Mosquitos success at high speed, low altitude penetrations but without some range charts from a manual we will just be guessing at the range penalty that might be involved.
 
Outside the domain of 8th AF, but wonder about Ploesti as well.
P-38's were tried. Were Mosquitoes tried?
 
I believe the Mosquito could carry 2 x 1000lb bombs (and probably 3 x 1000lb bombs) in the standard bomb bay, but the RAF preferred the 500lb or 4000lb HC bombs. With a slight modification to the bomb's tail the Mossie could also have carried 2 x AN Mk1 1600lb SAP bombs internally. But they were American bombs.

A Mosquito could also carry 2 x AP 2000lb Mk1 bombs inside the standard bomb bay. At least, they would fit inside the standard bomb bay.

Do you have a manual, bomb loading chart or mission reports that give such bomb loads?
These loads may have been possible but my rather limited references on the Mosquito makes no mention of them.
 
Do you have a manual, bomb loading chart or mission reports that give such bomb loads?
These loads may have been possible but my rather limited references on the Mosquito makes no mention of them.

I am not sure about the 2 x 1000lb bombs, as the reference I thought it wa sin doesn't say that. But, for the others it is a matter of dimensions.

The 1600lb AN MK1 SAP bomb is 83.5in long and 14.55in across the fins, which is wider than the body. We know that the 4000lb HC cookie was carried (with bulged bomb bay), and that is 30in diameter x 110in long. So probably wouldn't need tail modifications. The US ordinance manual 1944 (taken from a thread in here) states that the AN Mk 1 was used by the RAF as well.

The British AP 2000lb Mk1 was 13.5in diameter x 112.72in long. It may need cropping of the tail to fit lengthwise, but should comfortably sit side by side. The 500lb GP was 13in diameter x 70in long, but I can't find dimesnions of the 500lb MC bombs used in the Mossie.
 
400 Mosquitoes are a drop in the bucket compared to American requirements.


US Warplanes
Historically we produced about 3,300 A-20 light bombers during 1943. In this scenerio the Soviet Union would receive Lend-Lease B-17 heavy bombers and we would keep the A-20 light bombers. A reversal of the historical situation.


Consolidated B-24 Liberator - Wikipedia, the free encyclopedia
Historically the massive new Willow Run B-24 plant began production during October 1942. By 1944 they were producing 650 heavy bombers per month.

In this scenerio there would not be a massive B-24 program. Instead there would be a massive A-26 program, which would enter production as soon as R2800 engines are available. By mid 1943 we should be producing at least 400 A-26 light bombers per month in addition to the A-20s.


Of course this isn't going to happen as the officer who proposed it is now a military attaché stationed at Vladivostok. 8)
 
Would the 8th Air Force have been better off using Mosquitoes, particularly when operations were suspended due to unsustainable losses?

Were Mosquitoes ever tried or contemplated?

There are various arguments for and against.

As far as I know, the use of Mosquitos in large daylight raids was actually considered by a UK operational research group during the war - up to and including projections of loss rates - but never actually proposed, due to the realities of the air war.

On paper, a Mosquito B Mk IX or XVI could deliver a 3,000 lbs (6 x 500 lbs internally with an Avro bomb carrier) or 4,000 lbs (single 4,000 lbs HC or MC weapon) bomb load to Berlin. It would do so faster, using less fuel and risking less personnel (2 vs 10) than a B-17 or B-24, and likely do so at a lower loss rate.

However, there are several realities that would prevent this from actually being the case and going into large-scale service as a B-17/B-24 alternative.

Firstly, the first sub-type of the Mosquito capable of hauling a 4,000 lbs weapon - the B Mk IX - was not available until April 1943. Just 54 were produced before production switched over to the pressurised variant, the MK XVI, in July. This aircraft did not enter service until the end of November.

So, until the beginning of 1944, there are just 54 Mosquitos in service with the capability to haul a 4,000 lbs bomb load to Berlin ad back.

Using earlier types is not really an option. The earlier bomber Mks are slower, operate at a lower ceiling and have less internal bombload. A B Mk VI maxes out at about 380-385 mph at 20,000 ft, with 2,000 lbs internal (4 x 500 lbs). A B Mk XI/XVI maxes out at about 410 mph at 25,000 ft.

This means the intercept equation is much easier for German fighters - leading to significantly higher losses.

Secondly, the slow rate of production, combined with the drain on Mosquitos for other roles - notably night fighting, daylight fighter bombing and photo-reconnaissance - means that there is little chance of equipping a sizable bomber force with more capable variants until mid 1944.

This also rules out the Mosquito from 8th AF consideration. It wants to force the Luftwaffe into the sky and defeat its fighter force, all while blasting German production facilities.

Thirdly, conducting raids of just 20-40 hard to intercept aircraft is not going to attrit the Luftwaffe's daylight fighter capabilities, even if the raids are escorted once the P-51B/C joins the ETO after December 1943. Its simply not going to bring large numbers of German aircraft into the sky.

The bomber Mosquitos were also unarmed. Even though USAAF bomber gunners likely overclaimed in the region of 6-10 to one, they still brought down plenty of fighters over the course of the war.


The key to the Mosquito's low loss rate during the war was a combination of speed, altitude and night.

It had a significant margin of performance over most German night fighters. The aircraft operated at very high altitudes (pathfinding and marking Mosquitos bombed from as high as 32,000 ft) and it had the night sky to hide it from both flak and fighters. It also operated singly or in smallish groups, further complicating the intercept equation for its opposition.

Switching to daylight operations strips the Mosquito of most of its advantages.

German daylight single seat fighters have much higher performance than their night-time, multi-engine counterparts, removing the Mosquito of much of its performance advantage.

Daylight operations would also require larger formations, increasing the time German radar can pick and vector interceptors onto the aircraft. Most large Mossie ops were 'nusiance raids' with up to 60 aircraft vectored to the target independently.

If non-Oboe equipped Mosquitos wanted accuracy, they would have to bomb from lower heights, even in daylight (probably under 20,000 ft). This makes them more vulnerable to flak and fighters. One of the saving graces for Mosquito target markers was that Oboe allowed them to bomb relatively accurately form very high altitudes with relative immunity from interception and flak.

I love the Mossie, but using it to replace the 8th AF heavies on anything but a strictly limited basis doesn't make sense.
 
As far as I know, the use of Mosquitos in large daylight raids was actually considered by a UK operational research group during the war - up to and including projections of loss rates - but never actually proposed, due to the realities of the air war.

The research group suggested that Mosquitoes could prosecute the war more efficiently than the Lancaster. As much as 3 times, IIRC. This is about bombs on target, number of crew and their training, cost of aircraft procurement, raw materials and loss rates. In the end the guy at the top (Bomber Harris) was bent on destroying cities, for which the Mosquito was less suitable.



On paper, a Mosquito B Mk IX or XVI could deliver a 3,000 lbs (6 x 500 lbs internally with an Avro bomb carrier) or 4,000 lbs (single 4,000 lbs HC or MC weapon) bomb load to Berlin. It would do so faster, using less fuel and risking less personnel (2 vs 10) than a B-17 or B-24, and likely do so at a lower loss rate.

However, there are several realities that would prevent this from actually being the case and going into large-scale service as a B-17/B-24 alternative.

Firstly, the first sub-type of the Mosquito capable of hauling a 4,000 lbs weapon - the B Mk IX - was not available until April 1943. Just 54 were produced before production switched over to the pressurised variant, the MK XVI, in July. This aircraft did not enter service until the end of November.

So, until the beginning of 1944, there are just 54 Mosquitos in service with the capability to haul a 4,000 lbs bomb load to Berlin ad back.

The first Mosquitoes to carry the 4000lb HC bomb to Berlin and back were the BIVs. These missions started in early 1944 (March?).




This also rules out the Mosquito from 8th AF consideration. It wants to force the Luftwaffe into the sky and defeat its fighter force, all while blasting German production facilities.

This is not correct. The 8th AF wold have been happy to have never seen a LW fighter in opposition to their bombers. The whole aim of the 8th AF was to bomb the German industry.

Elaborate route plans and feints were devised to try to fool the LW as to the target, and to (hopefully) minimise the opposition the bombers faced. That changed in 1944 when Doolittle took over the 8th AF bomber groups and the P-51 became available in significant numbers. The elaborate routes and feints were gone - teh bombers were essentially bait for the LW, the aim being to destroy them in the air or on the ground with Mustangs.

In the Schweinfurt mission the LW dropped bombs on the 8th AF formation! And rockets were fired from beyond the reach of the B-17 gunners.



Thirdly, conducting raids of just 20-40 hard to intercept aircraft is not going to attrit the Luftwaffe's daylight fighter capabilities, even if the raids are escorted once the P-51B/C joins the ETO after December 1943. Its simply not going to bring large numbers of German aircraft into the sky.

Again, the aim of the bombers is to get bombs on the target. If the LW doesn't try to intercept them, all the better.




The key to the Mosquito's low loss rate during the war was a combination of speed, altitude and night.

It had a significant margin of performance over most German night fighters. The aircraft operated at very high altitudes (pathfinding and marking Mosquitos bombed from as high as 32,000 ft) and it had the night sky to hide it from both flak and fighters. It also operated singly or in smallish groups, further complicating the intercept equation for its opposition.

Switching to daylight operations strips the Mosquito of most of its advantages.

German daylight single seat fighters have much higher performance than their night-time, multi-engine counterparts, removing the Mosquito of much of its performance advantage.

Daylight operations would also require larger formations, increasing the time German radar can pick and vector interceptors onto the aircraft. Most large Mossie ops were 'nusiance raids' with up to 60 aircraft vectored to the target independently.

If non-Oboe equipped Mosquitos wanted accuracy, they would have to bomb from lower heights, even in daylight (probably under 20,000 ft). This makes them more vulnerable to flak and fighters. One of the saving graces for Mosquito target markers was that Oboe allowed them to bomb relatively accurately form very high altitudes with relative immunity from interception and flak.

Historically the switch went the other way. Mosquitoes started bombing during the day, but were in very small numbers. The loss of a single aircraft made for a significant mission loss rate (eg several missions were flown with 6 a/c, and if one was downed the lost rate was 16.67%). The 8th AF loss rates declned in the early part of 1944 not because of fewer aircraft lost, but because they sent more aircraft to target.

But even during the day the Mosquito was difficult for the LW to intercept.

The 2nd TAF continued day operations with their FBVIs.
 
The first Mosquitoes to carry the 4000lb HC bomb to Berlin and back were the BIVs. These missions started in early 1944 (March?).

Thank you. The early bulged B Mk IVs slipped my mind.

Still, just 54 were converted - numbers that would have been unacceptable for the 8th.


This is not correct. The 8th AF wold have been happy to have never seen a LW fighter in opposition to their bombers. The whole aim of the 8th AF was to bomb the German industry.

Elaborate route plans and feints were devised to try to fool the LW as to the target, and to (hopefully) minimise the opposition the bombers faced. That changed in 1944 when Doolittle took over the 8th AF bomber groups and the P-51 became available in significant numbers. The elaborate routes and feints were gone - teh bombers were essentially bait for the LW, the aim being to destroy them in the air or on the ground with Mustangs.

As you yourself point out, it depends on the time period. Prior to the adoption of the Point Blank directive and the introduction of a long-range escort in suitable numbers, the first part of your argument is true.

However, once Point Blank is signed, the bombers do become "bait" (such an unfortunate way to describe them though).

The Point Blank directive states it is to "impose heavy losses on German day fighter force and to conserve German fighter force away from the Russian and Mediterranean theatres of war".

Again, the aim of the bombers is to get bombs on the target. If the LW doesn't try to intercept them, all the better.

Agreed. But, combined with the Point Blank directive, the role of the bombers was more than just to hit targets in Germany. It was also to force German fighters to come to battle.

Historically the switch went the other way. Mosquitoes started bombing during the day, but were in very small numbers. The loss of a single aircraft made for a significant mission loss rate (eg several missions were flown with 6 a/c, and if one was downed the lost rate was 16.67%). The 8th AF loss rates declned in the early part of 1944 not because of fewer aircraft lost, but because they sent more aircraft to target.

But even during the day the Mosquito was difficult for the LW to intercept.

The 2nd TAF continued day operations with their FBVIs.

Yes, early Mosquito ops were daylight. Notably though, it was losses on low level fighter bomber ops that were high, not on high level bombing ops.

8th AF heavy bomber loss rates declined as both a function of larger numbers of aircraft AND less effective German fighter opposition.

In 1943, 70% of all 8th AF heavy bomber losses were due to fighters
In the first half of 1944, this is down to 58%
In the second half of 1944, its down to 25%

Flak becomes a much larger killer of 8th AF bombers from June 1944.

There are two notable drop off periods in 8th AF bomber losses: November 1943, at the suspension of deep penetration missions, and May 1944, when sortie rates climb beyond 10,000 per month for the first time.
 
However, once Point Blank is signed, the bombers do become "bait" (such an unfortunate way to describe them though).

The Point Blank directive states it is to "impose heavy losses on German day fighter force and to conserve German fighter force away from the Russian and Mediterranean theatres of war".

The key instrument in that was the use of the Mustang. Had the Mustang, and other escort fighters, not been available it would not have worked. If you can put sufficient bombers on operations, and 400 should be plenty, and they are attacking vital targets in Germany then the LW fighters have to respond. If not, the escort fighters can seek them out at their home bases - which they also did during 1944.




Thank you. The early bulged B Mk IVs slipped my mind.

Still, just 54 were converted - numbers that would have been unacceptable for the 8th.

As to the number of Mosquitoes, about 1/3 of the Mosquitoes made were FBVIs. Had the bomber Mossie been required for a larger part of the daylight bombing campaign then the production priorities would have shifted to the bomber variant.

And there were some 90 odd PRIXs built as well as the BIXs, and they could so easily have been made as bombers. I'm not sure exactly what had to be done to convert a PR to a B versiion, but surely it could not be much.

Canadian production started in 1943 too (IIRC), and they delivered nearly 250 BXXs (Canadian BIV with Packard Merlins), and 400 odd B25s (improved BXXs).

In all nearly 6000 of the 7781 Mosquitoes built were delivered during the war.
 
That doesn't mean German fighter aircraft had become ineffective. There were a lot more heavy flak shells in the sky during 1944 and they were aimed by improved radar.

Production of Luftwaffe 8.8cm heavy Flak guns.
Production Stats on German Tube-fired Weapons 1939-1945
183. 1939. Plus 42 larger 10.5cm and 12.8cm weapons.
1,130. 1940. Plus 290 larger weapons.
1,872. 1941. Plus 509 larger weapons.
2,876. 1942. Plus 766 larger weapons.
4,416. 1943. Plus 1,518 larger weapons.
1,933. 1944. Plus 1,795 larger weapons.
715. 1945. Plus 190 larger weapons.

Looking at the production record I would guess the massive 1943 production gave Luftwaffe heavy flak units their authorized level of equipment for the first time. That's why production could decline during 1944.
 
Yes, early Mosquito ops were daylight. Notably though, it was losses on low level fighter bomber ops that were high, not on high level bombing ops.

I agree with pretty much everything you've posted, but, depending on the ops you're referring to, I think you may be wrong here. The initial daylight bomber ops were costly at high level, much less so at low level. Both were more expensive than the fighter-bomber ops of 1944 (against V-1 sites and the like), with some heavier losses on individual raids in '44 and '45. I've not split the fighter-bomber ops and losses by day/night, though I suppose I have the info to do so. All up the fighter-bomber losses ran, so far as I've calculated, at about 1.4%, though those of 23 Sqn in the Med were about 1.8% in 1943.
 
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