What if America built De Havilland Mosquitoes instead of the B-17 Flying Fortress? (2 Viewers)

[FLYBOYJ]

Also I don't think it had the range to compete with a B-29

The B-29 had at least twice the range of the Mosquito

 

[wuzak]

Curtis LeMay recognized early that established peacetime doctrine of acceptable training and formation structure fell short of mission requirements in the ETO. The crafting of combat box formations to 'shrink' the footprint of the formations, selecting lead crews and carefully prepared target portfolios for IP and Bomb Aiming planning, removing ability of pilot to take evasive manuevers via AFE slaved to bombsight - were all major improvements over peacetime training. Other processes like 'bombing in synch with lead crews were also major improvements to overall squadron accuracy.

The Mk.XIV was more tolerant than the Norden for maneuvering bombers, and did not need as much time on the run to the target.

Low level bombing by Mosquitoes was done without the bomb sight.

Mosquitoes would not "bomb on the leader", because it would be a waste of the very few bombs. Instead they would bomb individually.

 

[wuzak]

The B-29 had at least twice the range of the Mosquito

Maybe 3 times when the B-29 had a light load.

 

[wuzak]

Are there RAF sources explaining that the Mosquito was being considered for high value precision targets at the ranges we are discussing for the Oil Campaign?

I though we were discussing the Mosquito as a possible strategic bomber generally, not just the Oil Campaign.

 

[drgondog]

I though we were discussing the Mosquito as a possible strategic bomber generally, not just the Oil Campaign.

The Oil Campaign was more interesting to me because unit bomb weight was cited as a deficiency for many 8th and 15th AF attack and RAF doctrine leaned toward the heavier bomb. You pointed out the US GP bomb had higher exlosive content per total weight of bomb which negated some of my reasoning.

 

[MiTasol]

I know the U.S. was building wooden aircraft but was it the same scale as the metal ones? I remember some 12000 + B-17Gs built and more B-24s than all B-17s. Did the U.S. have similar production runs of wooden aircraft. I'm not a carpenter, aeronautical engineer or sheet metal worker but aren't LARGE scale production runs easier with metals? I have an image of American industry based on steel products. I'm familiar with wooden boats of the time, my Sea Scout "Ship" had a 36 foot landing craft built by Chris Craft. I wrote its serial number down but that is lost.

Actually you raise a very valid point that most ignore.

Building wooden aircraft on a large scale is a far far bigger task than building metal aircraft on the same scale. Over 18,000 B-24s were built. Wooden, and part wooden, aircraft were smaller aircraft and only built in hundreds, and maybe very low thousands, in the USA.

A typical pressed metal wing rib is a single piece of metal with lightening holes and pressed flanges and pressed stiffeners. For a single metal aircraft this is costly to build but when you go to mass production you cut out the blanks using a pantograph router or similar in lots of 10 to 50 (forty 0.025 thick ribs being cut simultaneously make a stack only 1 inch high and take little more time than routing a single rib), then after cleaning and de-burring the blanks spend a couple of minutes in the press where in most cases multiple parts were pressed simultaneously, then a bit of rework and you turn out hundreds of each part per day with only a few men or women and tools. To maximize output many presses had four parts tables mounted NSEW with three being loaded/unloaded while one is actually in the press. The single stack of 12ft x 4ft sheets on the router table is cut into not just ribs but much of the "waste" is cut into smaller parts so that there is minimal real waste. All the shavings and small off-cuts were, in turn, recycled. Some plants used presses that in a single action blanked and shaped the component but they had much higher tooling costs and higher waste which was offset by the reduced man-hours.

With a wooden wing rib (or a Spitfire wing rib) each one requires a lot of man-hours to assemble from lots of individual parts that nearly all have to be individually cut to size and shape and which then have to be assembled in a jig to get the correct shape. They cannot be stack routed or press blanked. As well as requiring a lot of tradesmen, producing a large number of each part requires a large number of jigs and all the other tools required to make the minor parts. That in turn would require a much larger plant with all the attendant problems with moving ribs (or what ever) from dozens of output sources to the inspection department and component or final assembly lines. And that is before you add in cure times for the glues used, often in jigs which means even more jigs are required where you cannot remove the part until the glue cures, etc, etc, that are absent from a metal production line where the part leaves the form block or jig the moment it is completed. AND it is very difficult to productively recycle wood waste like shavings, sawdust and small off-cuts.

 

[SaparotRob]

Thanks for your reply MiTasol. You explained what I was alluding to far better than I could.
I had at one time been a production planner. It was nostalgic reading your post. I had several "bills of labor" or "routings" which contained many of the steps you listed.

 

[FLYBOYJ]

Actually you raise a very valid point that most ignore.

Building wooden aircraft on a large scale is a far far bigger task than building metal aircraft on the same scale. Over 18,000 B-24s were built. Wooden, and part wooden, aircraft were smaller aircraft and only built in hundreds, and maybe very low thousands, in the USA.

A typical pressed metal wing rib is a single piece of metal with lightening holes and pressed flanges and pressed stiffeners. For a single metal aircraft this is costly to build but when you go to mass production you cut out the blanks using a pantograph router or similar in lots of 10 to 50 (forty 0.025 thick ribs being cut simultaneously make a stack only 1 inch high and take little more time than routing a single rib), then after cleaning and de-burring the blanks spend a couple of minutes in the press where in most cases multiple parts were pressed simultaneously, then a bit of rework and you turn out hundreds of each part per day with only a few men or women and tools. To maximize output many presses had four parts tables mounted NSEW with three being loaded/unloaded while one is actually in the press. The single stack of 12ft x 4ft sheets on the router table is cut into not just ribs but much of the "waste" is cut into smaller parts so that there is minimal real waste. All the shavings and small off-cuts were, in turn, recycled. Some plants used presses that in a single action blanked and shaped the component but they had much higher tooling costs and higher waste which was offset by the reduced man-hours.

With a wooden wing rib (or a Spitfire wing rib) each one requires a lot of man-hours to assemble from lots of individual parts that nearly all have to be individually cut to size and shape and which then have to be assembled in a jig to get the correct shape. They cannot be stack routed or press blanked. As well as requiring a lot of tradesmen, producing a large number of each part requires a large number of jigs and all the other tools required to make the minor parts. That in turn would require a much larger plant with all the attendant problems with moving ribs (or what ever) from dozens of output sources to the inspection department and component or final assembly lines. And that is before you add in cure times for the glues used, often in jigs which means even more jigs are required where you cannot remove the part until the glue cures, etc, etc, that are absent from a metal production line where the part leaves the form block or jig the moment it is completed. AND it is very difficult to productively recycle wood waste like shavings, sawdust and small off-cuts.

Excellent post! In addition to this, repairs are way more problematic to complete because of glues and resins that must be used in a clean and environmentally controlled area. The more you repair a wood structure, the weaker the structure can become. Metal repairs are so much easier to do and can be done in almost any environment.

IIRC I believe de Havilland recommended that the Mosquito NOT be stored in the open elements, I can't remember where I read this, maybe someone has this reference available.

 

[drgondog]

The SBD worked extremely well in the hands of Navy pilots, as we know, but it seems to have proven vulnerable and not nearly as deadly accurate with Marine pilots, and had a fairly dismal record with Army pilots as the A-24 for example when used in New Guinea. I think it required a lot of training to reach it's full potential, and it was also pretty slow. I see the A-36 as potential rival in the role of land (island) based dive bomber, which could sink ships and also attack land targets, but would at least in theory be fast enough to pretty easily evade Ki-43s and A6Ms.

I think it could have had a niche for a while anyway.

In 1942 the AAF changed battlefield aircraft and doctrine from pre-war Observation and Light attack bomber (for interdiction role) to fast attack in which the light bomber (A-20) still had same role but fighter type required achieving battlefield air superiority . The 'dive bomber' requirement was a pancea offered by Arnold to satisfy Asst Secy War Lovett's passion for LW CAS capability via the Stuka. The A-24 type, slow dive bomber, was inserted during 1942 as a stopgap. Materiel Command was hyping another slow(but faster than SBD) CAS type with Brewster XA-32 when the A-36 turf war battle erupted between Planning and Requirements in HQ and Materiel Command at HQ and Wright Field (both under Echols) who lost to the A-36.

In fact, Arnold and Spaatz visited NAA as NAA was completing the Low Altitude Attack Fighter (Mustang with dive brakes and external pylons for combat tanks or 1000 lb or tank/bomb - end of Janary 1942, following a recommendation from Eaker as well as the CG of West Coast Air Defence (Lyons) following a test by 20th FG pilots between P-40, P-64, P-39 and XP-51. I believe, without direct quote from Arnold, that he decided to kill two birds with one stone (get Lovett off his back, and satisfy Planning and Requirements strong recommendtion that A-36 be purchased under the FY 41 budget allocation for dive/attack aircraft. I also believe that his meetings in London in May 1942 in which he was briefed by Hitchcock and RAF on the approved Merlin conversion to Mustang I further triggered approval by AAF in late May (contract in August) for NA-101 XP-51B. There are many data points for my conclusions but too drawn out for here.

The result was a.) A-36 was purchased, but from the very beginning it was conceived as a fast battlefield fighter - faster, with broader performance in speed and climb and range than P-39 and P-40 and set the table for migration Out of dive bombing with issuance of P-51A contract as follow on; and b.) set the table for Planning and Requirements to insist that the deliveries of the Mustang include Packard Merlin ASAP. The latter condition established that NA-99 AC-30479 be equipped to transition to NA-104 P-51B-5 and truncate the P-51A. Planning wanted the P-51B as THE battlefield air superiority fighter/tactical support/recon vehicle. The P-51B allocations for 1943 were to replace the P-39, P-40 (and P-38) for such - which is why the 9th AF received the priority.

Back to your point - there would never be enough A-36s to contemplate widespread tactical precision dive bombing on a widespread basis. When the first A-36s landed in MTO, the last A-36 had already been delivered on March 31, 1943. The last P-51A, following the A-36 at Inglewood, was delivered in June or July (have to chaeck) and the first P-51B-1-NA was delivered(engineless) at end of March, and flown in May.

When you project A-36 in SWP, think substitution for A-24, P-39, P-40, with more capability (accurate dive bombing and longer combat radius). The advantage to be gained was far less than devoting plant capacity to produce more P-51B/C.

 

[wuzak]

The Oil Campaign was more interesting to me because unit bomb weight was cited as a deficiency for many 8th and 15th AF attack and RAF doctrine leaned toward the heavier bomb. You pointed out the US GP bomb had higher exlosive content per total weight of bomb which negated some of my reasoning.

Two types of British general purpose bombs.

General Purpose (GP) bombs, which were in the inventory before WWII, had a charge-to-weight ratio of ~25-30%.
Medium capacity (MC) bombs, which were developed in the lead up and early in the war, had a charge-to-weight ratio of 50-60%.

MC bombs were equivalent in charge-to-weight ratio to US GP bombs and similar in shape.

The British 1,900lb GP bomb had 470lb of explosive filling, the 1,000lb MC bomb 475-525lb, depending on type.

The British 1,000lb GP bomb had 357-378lb of explosive filling.

The 500lb bomb had 210-232lb explosive filling.

The 4,000lb MC bomb had 2,166lb-2,265lb explosive filling.

The 4,000lb High Capacity (HC) bomb had 2,954-3,294lb explosive filling.

 

[SaparotRob]

Out of curiosity, were there ever large scale Mosquito raids of, say, 100 or so aircraft? It would be informative to compare similar sized missions of these two airplanes.

 

[WARSPITER]

After reading the premise and most of the posts in this what if I have come to the following conclusions;

1. The B17 was not a good multi-purpose twin engine aircraft.

2. The B17 was a good four engined bomber as per design.

3. The Mosquito was a good twin engine multi-purpose aircraft as per design.

4. The Mosquito was not a good four engine bomber.

I may have missed a few things here but it remains that as with all what ifs it is mostly in the the realm of personal preference.

 

[drgondog]

Out of curiosity, were there ever large scale Mosquito raids of, say, 100 or so aircraft? It would be informative to compare similar sized missions of these two airplanes.

RAF BC training doctrine did not emphasize large scale assembly of formations in day or night, nor associated close order formations to improve defense or shrink formation bombing footprint. In the case of the Mosquito, the question arises "Why bother?". Given dispatch of many small quantity formations, say in Flight of 4 to saturate defensive responses, the complexities of forming up for self protection are not necessary - the Mossie was undefended in single, small or large formations. Speed and surprise were the only defenses - so capitalize on strengths.

The question remains "Much higher precision bombing results per aircraft - sufficient to offset crew losses in 'new role' of long-range strategic taget assault. I truly have no clue, but doubt that Mosquitos would have effectively replaced B-17 and B-24 for long range bomber role on heavily defended targets

 

[SaparotRob]

I didn't think the Mosquito was used that way either. Perhaps there may have been some mission which used a large strike package of Mossies. Just wondering if it ever happened and then compare results to the B-17s. It wouldn't have been statistically valid. One mission to compare to the thousands(?) of B-17 missions

 

[FLYBOYJ]

After reading the premise and most of the posts in this what if I have come to the following conclusions;

1. The B17 was not a good multi-purpose twin engine aircraft.

2. The B17 was a good four engined bomber as per design.

3. The Mosquito was a good twin engine multi-purpose aircraft as per design.

4. The Mosquito was not a good four engine bomber.

I may have missed a few things here but it remains that as with all what ifs it is mostly in the the realm of personal preference.

Let me add to this based on the OP's question.

Could the US have built the Mosquito? Yes

I think under license Bellanca would be a perfect company for this based on their experience building wood aircraft.

Could the Mosquito have replaced the B-17 in a strategic role?

For some missions, yes but in the bigger picture no.

Bringing the Mosquito on line, getting a production license, signing contracts and building tooling would have taken at least 18 months if not longer. As mentioned earlier, General Arnold showed several manufacturers Mosquito drawings, no one wanted to touch it - but then again the AAC did not put up a solicitation for bid.

Could an "all-Mosquito" bomber force bring the same amount of destruction to Germany as the around the clock bombing by the RAF and USAAF did with 4 engine bombers?

IMO - No, however there were probably many applications where using the Mosquito "would have" been more efficient and effective.

Was the Strategic Bombing Campaign of Germany a complete failure?

Obviously not LOL! But in hindsight it could have been done more efficiently with less losses of airmen and aircraft.

Did the US "NEED" the Mosquito? Need no, "would have been nice to have" yes. As we know the Mosquito was used by the AAF as a night fighter and recon aircraft.

The Mosquito did show that in tactical and some strategic applications, the fast, low and precise fighter bomber can be more effective than the "bomb truck." Until the day of precision weapons and delivery systems came, you were still dropping unguided bombs. Everyone talks about mitigating civilian causalities but even with the most accurate bomber of the era, civilian causalities are going to happen.

Operation Carthage - Wikipedia

en.wikipedia.org

 

[SaparotRob]

So in summation, the B-17 rules!

 

[WARSPITER]

So in summation, the B-17 rules!

As I was told by a sagely machinist - I've got twelve inches but I only use it as a rule.

 

[Schweik]

I would have thought that would be knowledge necessary to form an opinion on this what-if.

I know top speeds are in the 360-410 mph range depending on the variant, that cruise speeds are 300 mph + and I know something about the operational history, which is enough. I didn't know the specific limitations of every single subtype. But I am interested and it's not the sort of thing Wikipedia provides conveniently.

 

[special ed]

Two quick items. Germans knew when raids would come and how large by the acft radios being turned on and tuned. Which led to cat and mouse turning on of radios which may or may not be going that day. As to the wooden wing ribs, in the 1950s I picked a wooden rib from a hangar trash barrel and used it for control line model building. The spruce became engine mounts and the plywood webs became firewall engine mounts for small engines. The assembly time for wooden ribs was prohibitive for mass production in war time. I still have a few pieces of both spruce and plywood and many, many of the small nails. During the assembly, the spruce long pieces were glued together with old time hide glue and the ply webs nailed into place to hold everything together while the glue dryed.

 

[Schweik]

In 1942 the AAF changed battlefield aircraft and doctrine from pre-war Observation and Light attack bomber (for interdiction role) to fast attack in which the light bomber (A-20) still had same role but fighter type required achieving battlefield air superiority . The 'dive bomber' requirement was a pancea offered by Arnold to satisfy Asst Secy War Lovett's passion for LW CAS capability via the Stuka. The A-24 type, slow dive bomber, was inserted during 1942 as a stopgap. Materiel Command was hyping another slow(but faster than SBD) CAS type with Brewster XA-32 when the A-36 turf war battle erupted between Planning and Requirements in HQ and Materiel Command at HQ and Wright Field (both under Echols) who lost to the A-36.

In fact, Arnold and Spaatz visited NAA as NAA was completing the Low Altitude Attack Fighter (Mustang with dive brakes and external pylons for combat tanks or 1000 lb or tank/bomb - end of Janary 1942, following a recommendation from Eaker as well as the CG of West Coast Air Defence (Lyons) following a test by 20th FG pilots between P-40, P-64, P-39 and XP-51. I believe, without direct quote from Arnold, that he decided to kill two birds with one stone (get Lovett off his back, and satisfy Planning and Requirements strong recommendtion that A-36 be purchased under the FY 41 budget allocation for dive/attack aircraft. I also believe that his meetings in London in May 1942 in which he was briefed by Hitchcock and RAF on the approved Merlin conversion to Mustang I further triggered approval by AAF in late May (contract in August) for NA-101 XP-51B. There are many data points for my conclusions but too drawn out for here.

The result was a.) A-36 was purchased, but from the very beginning it was conceived as a fast battlefield fighter - faster, with broader performance in speed and climb and range than P-39 and P-40 and set the table for migration Out of dive bombing with issuance of P-51A contract as follow on; and b.) set the table for Planning and Requirements to insist that the deliveries of the Mustang include Packard Merlin ASAP. The latter condition established that NA-99 AC-30479 be equipped to transition to NA-104 P-51B-5 and truncate the P-51A. Planning wanted the P-51B as THE battlefield air superiority fighter/tactical support/recon vehicle. The P-51B allocations for 1943 were to replace the P-39, P-40 (and P-38) for such - which is why the 9th AF received the priority.

Back to your point - there would never be enough A-36s to contemplate widespread tactical precision dive bombing on a widespread basis. When the first A-36s landed in MTO, the last A-36 had already been delivered on March 31, 1943. The last P-51A, following the A-36 at Inglewood, was delivered in June or July (have to chaeck) and the first P-51B-1-NA was delivered(engineless) at end of March, and flown in May.

When you project A-36 in SWP, think substitution for A-24, P-39, P-40, with more capability (accurate dive bombing and longer combat radius). The advantage to be gained was far less than devoting plant capacity to produce more P-51B/C.

I know all that. They wouldn't have needed many A-36 in the Pacific to make a difference. The A-24s got wiped out very quickly (for example they lost 7 out of 8 on one sortie from New Guinea). If they could have gotten say, 50 x A-36 which were going to MTO into the PTO battle area it could have made a significant difference, though it would not have been a game changer. It might have been a small nightmare for the Japanese though. A-36 were able to operate successfully in Italy for a while which means they had a pretty high surviveability, and their dive bombing was accurate enough to routinely take out bridges etc. so I suspect they could hit ships and barges.

I can also see P-51A being a useful fast recon bird for a couple of scenarios in the PTO.

As a fighter, the P-51A / Allison P-51 types did not do well, apparently because of some issues with the ailerons which were corrected when they converted to the Merlin.