# A navalised P-38 Lightning?



## Lucky13 (Apr 20, 2014)

Would it have been possible?


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## fubar57 (Apr 20, 2014)

"The US Navy acquired four F-5Bs from the USAAF in North Africa. They were designated FO-1 and were assigned the BuNos 01209/01212. They were operated exclusively as land- based aircraft and never from carriers. Lockheed had proposed a carrier-based version of the Lightning, the Model 822, with folding wings, arrester hooks, and a strengthened airframe. However, the Navy looked askance at such a large aircraft on its carrier decks, and they disliked liquid-cooled engines for carrier-based planes. Consequently, this project never got past the paper stage."

From P-38s with US Navy and Foreign Air Forces

Geo


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## Lucky13 (Apr 20, 2014)

Learn something new everyday....


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## fubar57 (Apr 20, 2014)

Moi aussi mon ami.

Geo


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## tomo pauk (Apr 20, 2014)

Lockheed's proposal for the USN (V-1710s, no turbos):

http://i729.photobucket.com/albums/ww291/joncarrfarrelly/MODEL_24_01.jpg

The P-38 with radials (Twin Wasps?; might be photoshopped):

http://img846.imageshack.us/img846/6600/escaneary.jpg


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## GregP (Apr 20, 2014)

How about this P-38? Sure to have a great rate of climb and superior acceleration, but not too sure about the armament suite...

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## wuzak (Apr 20, 2014)

fubar57 said:


> "The US Navy acquired four F-5Bs from the USAAF in North Africa. They were designated FO-1 and were assigned the BuNos 01209/01212. They were operated exclusively as land- based aircraft and never from carriers. Lockheed had proposed a carrier-based version of the Lightning, the Model 822, with folding wings, arrester hooks, and a strengthened airframe. However, the Navy looked askance at such a large aircraft on its carrier decks, and they disliked liquid-cooled engines for carrier-based planes. Consequently, this project never got past the paper stage."
> 
> From P-38s with US Navy and Foreign Air Forces
> 
> ...



In terms of outright size, the P-38 is no bigger than a TBF. Except when it comes to stowage.


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## BiffF15 (Apr 20, 2014)

Wuzak,

How "did" the Navy park them on board a carrier (particularly in the hanger deck)? I would imagine there is some tail to tail with overlap, and the P-38 is considerably wider (I would think) than the TBF.

Cheers,
Biff


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## wuzak (Apr 20, 2014)

BiffF15 said:


> Wuzak,
> 
> How "did" the Navy park them on board a carrier (particularly in the hanger deck)? I would imagine there is some tail to tail with overlap, and the P-38 is considerably wider (I would think) than the TBF.
> 
> ...



It appears from pictures that they are side by side. At least on deck.










But the P-38 would be wider with wings folded than the TDF, and that is what I meant. Taking off or landing the P-38 won't take up any more space than the TBF, but it will when it is being stored on deck or in the hangar.


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## BiffF15 (Apr 20, 2014)

Wuzak,

I was thinking the same thing, footprint wise. The curious question I have is where was the hook going to be located?

Cheers,
Biff


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## wuzak (Apr 21, 2014)

BiffF15 said:


> Wuzak,
> 
> I was thinking the same thing, footprint wise. The curious question I have is where was the hook going to be located?
> 
> ...



That is a good question.

The link Tomo gave does not seem to show a hook.

I would assume that a hook directly off the crew nacelle would not work so well?

Perhaps a big triangular frame hung off the booms, with the hook below the horizontal stabiliser?


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## tomo pauk (Apr 21, 2014)

The hook would extend down, angle against horizontal of maybe 60-70 deg, from central necelle. It is visible as a bar extending from the central nacelle to the aft side of the lowered main wheel.


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## rinkol (Apr 21, 2014)

One of the attractions of the P-38 layout was that the booms provided space for the turbosuperchargers and intercoolers. If these are removed in accordance with US Navy practice, this advantage is lost and the decrease in performance will be significant unless a two stage mechanically driven supercharger can be installed. This pretty much rules out an early service introduction.

From an operational perspective, for a carrier aircraft, two engines are a liability in the sense that a take-off or landing with an engine failure is likely to come to an unhappy ending. It might be added that the P-38 had a wing loading that was high compared to that of standard carrier aircraft of the time.

In addition to the hanger storage space issue, there are maintenance issues - there are two liquid cooled engines with 24 cylinders between them. Furthermore, these engines differ substantially in construction from those used on other carrier aircraft. There would have to be compelling reasons to justify the provision of additional replacement parts, equipment and trained maintenance personnel to say nothing of the extensive modifications that would be needed to the aircraft itself.





T


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## tomo pauk (Apr 21, 2014)

The P-38 was not using booms for inter-coolers, and the turbos themselves were pretty much 'atop' the wings. For the non-turbo P-38 to be of much use as a fighter, the intended costumer need to avoid the mistake RAF (and French) made - ordering the C-15 engines for it, instead of F3R and subsequent. The 'F' series were offering circa 10% more power under 13000 ft, and were more amenable for war emergency regime. 
It would be also good to incorporate handed engines (= left turning of the equivalent of the F3R), install 'proper', individual exhausts (instead of collector pipe) for some speed increase, extend the intake to take a form of the one used at P-40 or P-51 (for better use of ram effect), take care for balancing out the now-missing turbos (installing the Prestone coolers under/around the prop spinners? - seems like Lockheed's proposal for he USN was suggesting that). Actually, the proposal has a similar layout of cooler like the pre-P-38 had.
An engine failure when engine quits does not seem any happier thing  Pilot of the S/E aircraft whose engine quits miles from carrier, due to enemy action or otherwise, can't expect much, either.
The P-38 have had Fowler flaps, that allow for good low-speed abilities. Without turbos, it would be also much lighter, hopefully enough lighter to make out for weight gains due to now being carrier capable.

edit: Actually, scratch that relocation of the cooling radiators, we need either less weight on front, or more aft


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## VBF-13 (Apr 22, 2014)

I'm not understanding what advantages it would bring in relationship to what the Navy already had that would make it worth trying to figure out how to fold it up and hook it and otherwise outfit it to just fit it in the elevators.


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## tomo pauk (Apr 22, 2014)

Assuming the USN proceeds anyway with a navalized P-38, there are several advantages vs. other CV-borne planes. Against F6F and F4U, it can be available much earlier (a major advantage). It will out-climb both. From Autumn of 1943 on, it would be able to provide a substantially better range/radius.
Against F4F, it can offer much better speed and climb performance (despite capability to carry a more powerful gun battery), better range/radius, capability to haul a substantial bomb payload and still be pretty much immune to interception by Zero and Oscar (and earlier types). In fighter trim, it will be much faster than anything Japanese can throw in for much of a duration of ww2, especially in the earlier years.
Lockheed's proposal included folding wings and, of course, hook.


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## Shortround6 (Apr 22, 2014)

Without opening a 2nd production line it is not really available at all. Not without shorting the Army. 
Lockheed made 207 P-38s in 1941, many of them _not_ combat capable.
Lockheed made 1479 P-38s in 1942 581 of them in last 4 months. 39% in the last 25% of the year. 
By April-May of 1943 F4U production is swapping back and forth with P-38 production. 

How long to design and tool up for folding wing? 

BTW, take off for a P-38F with a 40mph head wind was 490 ft at 15,500lbs, 700 ft at 17,500lbs and 950 ft at 19,500lbs. basic weight of an "F" was 13,000lbs. take off distances are at 0 degrees C or 32 degrees F, increase 10% for every 20 Degrees above 0C/32F or 40-50% in the tropics. 

Weight of pilot, reduced oil, 20mm ammo and under 1/2 ammo for .50 cals and 230 gals of fuel is 2049lbs. 
Weight of pilot, full oil, 20mm ammo and full ammo for .50 cals and 300 gals of fuel is 2909lbs. Best approach speed (not stall or landing speed) was 100mph at 13,500lbs. Stall speed ws 69mph at 15,000lbs. 

You can pretty much forget flying off the carrier deck without catapult with any sort of under wing load.


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## BiffF15 (Apr 22, 2014)

How would you recover a P-38 that is single engine and heavy weight (no capability to jettison internal fuel)? 

Cheers,
Biff


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## VBF-13 (Apr 24, 2014)

Shortround6 said:


> Without opening a 2nd production line it is not really available at all. Not without shorting the Army.
> Lockheed made 207 P-38s in 1941, many of them _not_ combat capable.
> Lockheed made 1479 P-38s in 1942 581 of them in last 4 months. 39% in the last 25% of the year.
> By April-May of 1943 F4U production is swapping back and forth with P-38 production.
> ...


That's probably why these weren't even considered in the trials. These are oddballs on carriers, everybody could see that.


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## tomo pauk (Apr 24, 2014)

A monoplane carrier-borne aircraft were looking as an oddball, until the people really tried it. So did the 2-engined jobs, until tried. Heck, all aircraft were looked upon as oddballs prior ww1, let alone naval A/C.



Shortround6 said:


> Without opening a 2nd production line it is not really available at all. Not without shorting the Army.
> Lockheed made 207 P-38s in 1941, many of them _not_ combat capable.
> Lockheed made 1479 P-38s in 1942 581 of them in last 4 months. 39% in the last 25% of the year.
> By April-May of 1943 F4U production is swapping back and forth with P-38 production.



Yep, the production of the P-38s only really hit the stride after there was no that much need for them, like in 1944/45. 



> How long to design and tool up for folding wing?



The proposal was dated as of 1937. Should be tested by 1939 if the Navy wants it?



> BTW, take off for a P-38F with a 40mph head wind was 490 ft at 15,500lbs, 700 ft at 17,500lbs and 950 ft at 19,500lbs. basic weight of an "F" was 13,000lbs. take off distances are at 0 degrees C or 32 degrees F, increase 10% for every 20 Degrees above 0C/32F or 40-50% in the tropics.
> Weight of pilot, reduced oil, 20mm ammo and under 1/2 ammo for .50 cals and 230 gals of fuel is 2049lbs.
> Weight of pilot, full oil, 20mm ammo and full ammo for .50 cals and 300 gals of fuel is 2909lbs. Best approach speed (not stall or landing speed) was 100mph at 13,500lbs. Stall speed ws 69mph at 15,000lbs.
> You can pretty much forget flying off the carrier deck without catapult with any sort of under wing load.



For a take off weight of 32000 lbs, the B-25 was supposed to use 1400 ft of runaway at 40 mph headwind, 0 deg C; at 28000 lbs, it was 1000 ft. The Doolittle raiders weighted 31000 lbs, yet managed to take off at under 500 ft of the deck space. No assist used.

BiffF15 said:



> How would you recover a P-38 that is single engine and heavy weight (no capability to jettison internal fuel)?



The P-38 didn't have problems flying on one engine. Fly around until you've used up the fuel and then land.


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## Shortround6 (Apr 24, 2014)

tomo pauk said:


> A monoplane carrier-borne aircraft were looking as an oddball, until the people really tried it. So did the 2-engined jobs, until tried. Heck, all aircraft were looked upon as oddballs prior ww1, let alone naval A/C.



Stretching things a wee bit??? 
The twin engine carrier planes weren't really tried until carriers and carrier decks got much bigger than they were in the late 30s and very early 40s. 





> Yep, the production of the P-38s only really hit the stride after there was no that much need for them, like in 1944/45.



same could be said for a number of US aircraft. Like 3130 F4Fs built in 1944 out of 7904 for the entire war. Less said about P-39 and P-40 production in 1944 the better 





> The proposal was dated as of 1937. Should be tested by 1939 if the Navy wants it?



Using what for engines? The navy did test the Airabonita : Bell XFL Airabonita - Wikipedia, the free encyclopedia

But a 1939 version would use the C series engines at best with turbo operation being somewhat problematic?
Service version would happen when using what for engines? 



> For a take off weight of 32000 lbs, the B-25 was supposed to use 1400 ft of runaway at 40 mph headwind, 0 deg C; at 28000 lbs, it was 1000 ft. The Doolittle raiders weighted 31000 lbs, yet managed to take off at under 500 ft of the deck space. No assist used.



What you can pull off for a one shot, special mission with specially trained crews is not what is acceptable for day in, day out service. Trying to time the take-off for maximum upward pitch of the carrier deck when the plane crosses the bow so you can trade the most altitude for airspeed (sort of like the ski jump flight deck used for harriers) was not a good idea for day in, day out operations in all weathers/climates.


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## gjs238 (Apr 24, 2014)

Shortround6 said:


> Less said about P-39 and P-40 production in 1944 the better



Do you feel that production of these craft should have ended sooner?


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## tomo pauk (Apr 24, 2014)

Shortround6 said:


> Stretching things a wee bit???
> The twin engine carrier planes weren't really tried until carriers and carrier decks got much bigger than they were in the late 30s and very early 40s.



The RN conducted tests of the Sea Mosquito aboard of the 766 ft long HMS Indefatigable. The USN Lex Sara carriers were 888 ft long, Essex was at 872 ft. Hornet was at 825 ft. The HMS Eagle (1946) was 812 ft long. 



> same could be said for a number of US aircraft. Like 3130 F4Fs built in 1944 out of 7904 for the entire war. Less said about P-39 and P-40 production in 1944 the better



Agreed.



> Using what for engines? The navy did test the Airabonita : Bell XFL Airabonita - Wikipedia, the free encyclopedia
> But a 1939 version would use the C series engines at best with turbo operation being somewhat problematic?
> Service version would happen when using what for engines?



Obviously, the 1st examples will use the C series. In early 1941, the 1st F series are available.



> What you can pull off for a one shot, special mission with specially trained crews is not what is acceptable for day in, day out service. Trying to time the take-off for maximum upward pitch of the carrier deck when the plane crosses the bow so you can trade the most altitude for airspeed (sort of like the ski jump flight deck used for harriers) was not a good idea for day in, day out operations in all weathers/climates.



The take off distance was reduced to ~30% by the 'raiders'. 
The 'P-38' pilots will need to cut the distance to ~50% if they don't want to hit the water, that is for overweight condition (19500 lbs - ie. 2 x 300 gals DTs; hopefully no one will try to take off with those from CV?). With 2 x 150 gal DTs, the P-38 weighted 17700 lbs ( for 700+ ft TO distance), and some 1000 lbs less with 2 x 75 gal DTs. 

BTW: how much time it took for the carrier-borne A/C to take off? How much feet will the carrier cover during that time?


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## Balljoint (Apr 24, 2014)

A good carrier could make maybe 33 knots and usually a bit of head wind. Easiest to add this to aircraft speed. Maybe it’s just an illusion, but a plane seems to accelerate at a better rate once it gets moving.

I doubt that the B-25s could have taken of n the same distance from a static runway.


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## VBF-13 (Apr 25, 2014)

They couldn't have. They're dropping some too when they go off the end but have the momentum and thrust to overcome that.


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## BiffF15 (Apr 25, 2014)

tomo pauk said:


> BiffF15 said:
> 
> The P-38 didn't have problems flying on one engine. Fly around until you've used up the fuel and then land.




Tomo,

On all twins I have flown so far engine out approaches are flown at a lesser flap setting and higher speed (greater stall margin / power reserve). Also fighters, unlike airliners, generally land sooner rather than later (engines inside the plane vice out / less redundancy of systems) with the mentality that the problem will continue to grow. Both of those situations drive getting on the deck sooner rather than later, and the higher trap speed will introduce the need for stronger cables, and or the boat to move faster through the water to generate a lower approach speed for the plane.

Cheers,
Biff


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## Conslaw (Apr 25, 2014)

In 1943, when the new carriers were ready, the Hellcat was also ready, and the Hellcat was pretty much the perfect aircraft for the time and place. For 1942, the Navy was already making compromises in performance to get as many planes on deck as possible. The F4F-4, with folding wings was slower than the F4F-3, but you could fit half again as many on the ship. The challenge then was to produce the planes and get them on the ship when needed; a task that would have been more difficult with a bigger plane. I might rather have a P-38 than an F4F-4, but most of the time I'd rather have 2 F4F-4s than 1 P-38, and that's the real relevant trade-off.

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## tomo pauk (Apr 25, 2014)

Good point re. 2 folding wing A/C being better than one non-folding. That is also an argument against other fighters that could replace the F4F-4, like the 'hooked' P-40, Spitfire, or Sea Hurricane.
The folding wing P-38 should have span of circa 30 ft, and length of 38 ft. F4U 'folded' was at 17 ft, the F4F-4 at just 14.6 ft, and non folded at 38 ft. Both USN fighters being also shorter than P-38, ~5 and ~10 ft respectively.
The F6F was absent from CV service units for 2/3rds of 1943.



BiffF15 said:


> Tomo,
> 
> On all twins I have flown so far engine out approaches are flown at a lesser flap setting and higher speed (greater stall margin / power reserve). Also fighters, unlike airliners, generally land sooner rather than later (engines inside the plane vice out / less redundancy of systems) with the mentality that the problem will continue to grow. Both of those situations drive getting on the deck sooner rather than later, and the higher trap speed will introduce the need for stronger cables, and or the boat to move faster through the water to generate a lower approach speed for the plane.
> 
> ...



Thanks for the overview, Biff. 
The P-38 in engine-out situation will have a fair chance to limp back near the friendly ships or ground units, contrary to a single-engined A/C in same situation.


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## nuuumannn (Apr 25, 2014)

Forget folding wings, installation of a hook etc. The only thing that's going to get a P-38 serving on a US Navy carrier deck was if it had radial engines. Besides, what could the P-38 offer that the F6F and F4U within the time frame did not have that the US Navy needed, apart from two engines, and even then, they were the wrong kind.

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## tomo pauk (Apr 25, 2014)

For the USN, Bell redesigned the P-39 into the Airabointa, that came out as an under-performer and was cancelled because of that - ie. the USN was not strictly against the liquid cooled engines, if the aircraft carrying them were able to perform notably better than usual radial-engined ones.
Against the F4U and F6F, the navalized P-38 can offer earlier timing.


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## nuuumannn (Apr 25, 2014)

I dunno, Tomo, based on what Shortround and the others are saying, can it really? I don't believe that the Airabonita is a good example of the US Navy showing interest in an inline fighter, to be frank. If the navy was to invest in an earlier fighter, wouldn't a purpose built naval aircraft be a better bet, rather than disrupt army contracts to build a derivative of an existing design? Boils down to that typical argument of this kind of what if scenario, doesn't it; go with what you've got or go for an entirely new design. Surely, the time taken in modifying an existing design would/could be as much as starting from scratch.


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## Shortround6 (Apr 25, 2014)

Not a lot earlier. 
Not unless you come up with a 2nd production line/manufacturing facility.
Not unless you fix the problems with the early turbo systems.
Putting a wing fold in the middle of leading edge inter-cooler is going to be a real maintenance headache ( or performance killer). Please remember that the P-38H was manufactured in parallel with the P-38J for a number of months becasue Lockheed could NOT get enough of the J type inter-coolers so the idea of 'moving' the inter-coolers into the booms and out of the leading edges needs a bit more thought. 

With the US NOT involved in a shooting war development pre Dec 7th seemed to take a lot longer than development post Dec 7th. 
You need the Navy version designed, tested, and _ready_ for production when? 
P-38E was the first combat capable P-38 with over 2000 changes from the P-38D, First P-38E rolls out of the Factory in Nov 1941. 
A few F-4 recon planes show up in Australia in April 1942 but the P-38 fighter doesn't see combat in in squadrons until Aug 1942. 

Aug 9th sees P-38s shoot down 2 flying boats in the Alaska area, Aug 22nd sees P-38s show up at Henderson field (in less than squadron strength), Aug 29th sees first attempt at intercept over England. 
At the end of 1942/Jan 1943 P-38s are in short supply with units (squadrons, not groups) in the Pacific operating mixed with P-39s. There are about 90 in North Africa and even updated/refurbished P-38Es are being moved to North Africa (the G went into production about 6 months earlier, June of 1942).

You need a few hundred extra P-38s to put any real numbers on carriers. A sobering statistic is " The United States had manufactured about 294,000 aircraft for the war effort. Of that number, 21,583 (7.34%) were lost in the United States in test flights, ferrying, training accidents, etc., and 43,581 were lost en route to the war and in overseas operations."


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## tomo pauk (Apr 25, 2014)

Lockheed was awarded with contract for 667 of future Lightnings for the UK and France in April of 1940. By that time, the USAF ordered only 80 of P-38s. If the USN really wants the 'P-38s' on their decks, and signs the contract for, say, 250 of those in 1938 or 39, they can have the final say about how much, or any Lightnings will be exported. Lockheed can, due to a firm and big (for peace time) order expand their facilities and manpower more promptly than historically. Once the USAF and Europeans make their big orders, the USA can start to look around for second production source.



> I don't believe that the Airabonita is a good example of the US Navy showing interest in an inline fighter, to be frank.



Not sure what to make out of this - anyway we cut it,Bell reworked the P-39 to create the fighter, upon request from USN.



> If the navy was to invest in an earlier fighter, wouldn't a purpose built naval aircraft be a better bet, rather than disrupt army contracts to build a derivative of an existing design? Boils down to that typical argument of this kind of what if scenario, doesn't it; go with what you've got or go for an entirely new design. Surely, the time taken in modifying an existing design would/could be as much as starting from scratch.



I agree that a purpose-built CV fighter with a V-12 should do better than a quick fix of the ground-based fighter. The USN was probably hoping they would have the Airabointa in service in shorter time, than it would be possible for a brand new design.


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## Shortround6 (Apr 25, 2014)

nuuumannn said:


> I dunno, Tomo, based on what Shortround and the others are saying, can it really? I don't believe that the Airabonita is a good example of the US Navy showing interest in an inline fighter, to be frank. If the navy was to invest in an earlier fighter, wouldn't a purpose built naval aircraft be a better bet, rather than disrupt army contracts to build a derivative of an existing design? Boils down to that typical argument of this kind of what if scenario, doesn't it; go with what you've got or go for an entirely new design. Surely, the time taken in modifying an existing design would/could be as much as starting from scratch.



The Navy, after talks/ sales pitches and negotiations, had issued contracts for the XF4U, XF5F and XFL-1 (Airabonita) by the end of 1938. Bell had completed a full scale mock up by Dec 19/20th 1938. A number of delays and problems crept in, the contract didn't provide enough money to Bell who was trying to develop _3_ new fighters at the same time. By Dec 1939 the plane was considerably over weight ( not a surprise as the XP-39 was around 10% overweight) and Allison was months late in delivering the engine, engine doesn't show up until 4 months after the prototype was supposed to fly. 
Navy modifications (tail wheel landing gear) required a total redesign of the cooling system (new wheels went were radiators were on the Army Version) and much trouble was encountered getting the new radiator ducts/housing to work properly. Test flying (and modifications) dragged on through 1940 and into 1941. One series of tests used a hook equipped XP-39B which resulted in the conclusion that the XP-39B was not adequately stressed for carrier use which resulted in the Airabonita having a considerably different airframe structure than the XP-39B. 

Bell continued to 'pitch' a version of the Airabonita to the Navy that would include tricycle landing gear, folding wings and a two stage engine ( A folding wing XP-39E or P-63) but the Navy didn't bite.

Companies can propose all sorts of things and modifications of existing designs. There is no guarantee what so ever that they will actually work.


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## nuuumannn (Apr 25, 2014)

> I don't believe that the Airabonita is a good example of the US Navy showing interest in an inline fighter, to be frank.



Sorry Tomo, perhaps I should have clarified a bit on this, but SR has beat me to it in the above post.



> I agree that a purpose-built CV fighter with a V-12 should do better than a quick fix of the ground-based fighter. The USN was probably hoping they would have the Airabointa in service in shorter time, than it would be possible for a brand new design.



I can see the reasoning behind that though, just that the existing options available were not the best in terms of timing, as it turns out.


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## nuuumannn (Apr 25, 2014)

Just adding to my response above, since the XF4U was issued a contract at the same time, I think the navy made the right choice and yes, this is based on hindsight, which the navy did not have, granted, but if you take the time factor into consideration, the options available were going to take as long as they did - the technical issues at least, with getting the Corsair aboard carriers (even if they were FAA) at any rate. Modifying an existing design would not necessarily take less time, particularly the P-38.


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## Conslaw (Apr 26, 2014)

I will give Lucky13 (who started the thread) credit for being openminded towards a twin-engined naval fighter. I don't think that during the war the Navy was open-minded enough about two engined planes, even though they commissioned the XF5F. Eventually they proved that even a medium bomber like the B-25 could not just take off, but also land safely on a carrier with proper preparation. The British Sea Hornet was mentioned. That plane, "essentially" a navalized Mosquito, served on British ships shortly after World War II. Perhaps a naval P-38 would have been useful flying in small numbers from carriers for particularly critical missions. From reading about the F7F program, the Navy could have had that plane in combat before the end of 1944 if it would have been considered to be crucial to do so.


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## swampyankee (Apr 27, 2014)

tomo pauk said:


> For a take off weight of 32000 lbs, the B-25 was supposed to use 1400 ft of runaway at 40 mph headwind, 0 deg C; at 28000 lbs, it was 1000 ft. The Doolittle raiders weighted 31000 lbs, yet managed to take off at under 500 ft of the deck space. No assist used.



At a first guess, the Doolittle raiders took off at a speed below Vmc​. This would not be done from a land base, and would have meant that the result of an engine failure on take-off would have been a crash.


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## Koopernic (Apr 28, 2014)

nuuumannn said:


> Forget folding wings, installation of a hook etc. The only thing that's going to get a P-38 serving on a US Navy carrier deck was if it had radial engines. Besides, what could the P-38 offer that the F6F and F4U within the time frame did not have that the US Navy needed, apart from two engines, and even then, they were the wrong kind.



Exactly what problem did the USN have with liquid cooled engines? The RN had no issues at all it seems. The P-40 likely would have made a good carrier fighter early in the war, possibly better than the wildcat.


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## Shortround6 (Apr 28, 2014)

Koopernic said:


> Exactly what problem did the USN have with liquid cooled engines? The RN had no issues at all it seems. The P-40 likely would have made a good carrier fighter early in the war, possibly better than the wildcat.



The Navy had become disillusioned with liquid cooled engines back in the 20s. When you are flying long distances over water having one more thing to go wrong ( a liquid cooling system) was not desired. Granted by 1939/40 the liquid cooling systems had gotten better ( but still not perfect). Glycol is also flammable and the Navy used the excuse that they didn't want to store/handle hundreds of gallons of an _additional_ flammable liquid on their carriers. 

The P-40 would have made a lousy carrier fighter with around 40% longer take-off distances required, lousy view over the nose and landing speed 15-20% higher than an F4F. Just becasue you can fly P-40s off a carrier deck to a land base doesn't mean you can operate P-40s for weeks on end from a carrier.


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## rinkol (Apr 28, 2014)

Koopernic said:


> Exactly what problem did the USN have with liquid cooled engines? The RN had no issues at all it seems. The P-40 likely would have made a good carrier fighter early in the war, possibly better than the wildcat.



The US Navy valued low and medium altitude performance, reliability and low maintenance. Air cooled radial engines were a good fit to these criteria. Furthermore, to the extent that such engines offered high power for a given installed weight, they offered potential advantages concerning the climb rate; this was important for being able to launch and position aircraft favorably to rapidly respond to airborne attacks. The reduced vulnerability to combat damage may have been another factor - the loss of an engine over open water is a particularly unattractive proposition. 

The RN seems to have been very happy to acquire and operate F4Fs and F6Fs. They appear to have been surprised by developments in aviation and military doctrine; many of their aircraft at the beginning of the war were hopelessly inferior in performance to contemporary land based types, hence the improvised adaptation of Hurricanes and Spitfires. The reputation of Rolls Royce may have been a factor in favoring the usage of liquid cooled engines in aircraft such as the Firefly and Barracuda, but neither of these types were anything special from a performance perspective. The later Sea Fury and Firebrand used the Centaurus radial in preference to the Sabre and Griffon.


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## RCAFson (Apr 28, 2014)

rinkol said:


> The US Navy valued low and medium altitude performance, reliability and low maintenance. Air cooled radial engines were a good fit to these criteria. Furthermore, to the extent that such engines offered high power for a given installed weight, they offered potential advantages concerning the climb rate; this was important for being able to launch and position aircraft favorably to rapidly respond to airborne attacks. The reduced vulnerability to combat damage may have been another factor - the loss of an engine over open water is a particularly unattractive proposition.
> 
> The RN seems to have been very happy to acquire and operate F4Fs and F6Fs. They appear to have been surprised by developments in aviation and military doctrine; many of their aircraft at the beginning of the war were hopelessly inferior in performance to contemporary land based types, hence the improvised adaptation of Hurricanes and Spitfires. The reputation of Rolls Royce may have been a factor in favoring the usage of liquid cooled engines in aircraft such as the Firefly and Barracuda, but neither of these types were anything special from a performance perspective. The later Sea Fury and Firebrand used the Centaurus radial in preference to the Sabre and Griffon.





Which Navy, in 1939, fielded carrier aircraft that were not hopelessly inferior to to contemporary land types?


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## rinkol (Apr 28, 2014)

The US and Japanese navies had reasonably modern bombers (Devastator and B5N1) in service during the late 1930s and had advanced fighters and bombers in the pipeline. The British were forced into the expedient of producing a navalized version of the Spitfire (Seafire) which only became available in the second half of 1942 and was hardly an ideal carrier aircraft.


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## stona (Apr 28, 2014)

Shortround6 said:


> Glycol is also flammable and the Navy used the excuse that they didn't want to store/handle hundreds of gallons of an _additional_ flammable liquid on their carriers.



Anything will catch fire if it gets hot enough in the right conditions but ethylene glycol is not particularly flammable. I keep seeing this cited as a reason for not storing it on US carriers. but why? Is there any evidence that the USN used this as an excuse?
It has a flash point of 111 degrees Celsius, not dissimilar to diesel fuel and a bit lower than other fuel oils you'd expect to find on such vessels. The petrol you put in your car has a flash point around -45 degrees Celsius. Ethylene glycol has an auto ignition temperature (only relevant if things around it get very hot) of 410 degrees Celsius.

There are other problems associated with storing the pure compound, but it can simply be stored in an aqueous solution.

I don't know much about the possibilities of the P-38 as a carrier aircraft, but I do have a degree in chemistry 

Cheers

Steve


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## FLYBOYJ (Apr 28, 2014)

stona said:


> Anything will catch fire if it gets hot enough in the right conditions but ethylene glycol is not particularly flammable. I keep seeing this cited as a reason for not storing it on US carriers. but why? Is there any evidence that the USN used this as an excuse?



I've seen it written somewhere and it was spoken about when I through firefighting school while in the USNR. The word (and joke) was "If it was up to the Navy, they wouldn't have any flammable liquids on a carrier, including jet fuel."


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## stona (Apr 28, 2014)

FLYBOYJ said:


> I've seen it written somewhere and it was spoken about when I through firefighting school while in the USNR. The word (and joke) was "If it was up to the Navy, they wouldn't have any flammable liquids on a carrier, including jet fuel."



It's a nonsense reason though. WW2 carriers must have stored vast amounts of aviation fuel for their aircraft and that really is flammable. Storing a fluid with properties (as far as flammability goes) not that different from the fuel oil they ran the carrier on can't really have been a fire hazard. I'm not saying that the supposed flammability of the glycol wasn't used as a reason by people prejudiced against the use of liquid cooled engines, I simply don't know, but it is not a valid reason.
Cheers
Steve


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## FLYBOYJ (Apr 28, 2014)

stona said:


> It's a nonsense reason though. WW2 carriers must have stored vast amounts of aviation fuel for their aircraft and that really is flammable. Storing a fluid with properties (as far as flammability goes) not that different from the fuel oil they ran the carrier on can't really have been a fire hazard. I'm not saying that the supposed flammability of the glycol wasn't used as a reason by people prejudiced against the use of liquid cooled engines, I simply don't know, but it is not a valid reason.
> Cheers
> Steve


If was just one more bilge or storage locker to fill, an excuse to stay away from in lines, or just some command master chief's order, who knows, but it was policy, end of story.


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## RCAFson (Apr 28, 2014)

rinkol said:


> The US and Japanese navies had reasonably modern bombers (Devastator and B5N1) in service during the late 1930s and had advanced fighters and bombers in the pipeline. The British were forced into the expedient of producing a navalized version of the Spitfire (Seafire) which only became available in the second half of 1942 and was hardly an ideal carrier aircraft.



And the RN had the Skua in service in Sept 39 while the Albacore, which was generally superior to the Devastator, was just completing it's trials and was awaiting volume production of the Taurus engine. The USN would not field a replacement for the TBD until mid 1942. The first production Fulmar flew in Jan 1940 and it would be almost another two years before the FAA received any folding wing fighters from Grumman and the F4U was not carrier qualified, even by the RN until late 1943 and not by the USN until early 1944. The RN planned to have the Firefly in service in 1941 and the Barracuda in late 41/early 42; those plans took a beating after France fell, as FAA production priorities took a distant 2nd to the RAF. I suspect that if Japan or the USA had a hostile army and airforce parked 20 miles offshore that their naval aircraft production plans would have also suffered numerous delays.

The FAA navalized both the Hurricane and Spitfire but then again, there was nothing available from the USA until mid 1943, that could match or exceed either aircraft's performance as naval fighters. In mid/late 1942 the USN was desperately trying to match the A6M's performance while the FAA was having to tackle the 109f and FW190, hence the need for Seafires.


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## OldSkeptic (Apr 29, 2014)

RCAFson said:


> And the RN had the Skua in service in Sept 39 while the Albacore, which was generally superior to the Devastator, was just completing it's trials and was awaiting volume production of the Taurus engine. The USN would not field a replacement for the TBD until mid 1942. The first production Fulmar flew in Jan 1940 and it would be almost another two years before the FAA received any folding wing fighters from Grumman and the F4U was not carrier qualified, even by the RN until late 1943 and not by the USN until early 1944. The RN planned to have the Firefly in service in 1941 and the Barracuda in late 41/early 42; those plans took a beating after France fell, as FAA production priorities took a distant 2nd to the RAF. I suspect that if Japan or the USA had a hostile army and airforce parked 20 miles offshore that their naval aircraft production plans would have also suffered numerous delays.
> 
> The FAA navalized both the Hurricane and Spitfire but then again, there was nothing available from the USA until mid 1943, that could match or exceed either aircraft's performance as naval fighters. In mid/late 1942 the USN was desperately trying to match the A6M's performance while the FAA was having to tackle the 109f and FW190, hence the need for Seafires.



Correct. Everyone uses things like the the Italian landings (etc) to slag off the Seafire, but it was the only plane at the time (US and UK) that could hold it's own with a 109 of the era (not many 190s in that arena) . It wasn't perfect by any means and the UK had to use (because of idiotic shipbuilding decisions) escort carriers as 'real' carriers. And they were unlucky, slow ECs with zero wind.... whoops, but they did the job. Imagine a Wildcat vs a 109F or G of the time..... slaughter city.


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## stona (Apr 29, 2014)

FLYBOYJ said:


> but it was policy, end of story.



Is there any evidence for that? It seems to be one of these things that has accrued credibility by repetition whilst being based on a fallacy, the flammability of glycol. I'm genuinely interested and would love to see some evidence to back up the contention. In the absence of any evidence it should be discounted as a reason and consigned to the myth bunker (which is bulging at the seams since the internet came into being  )
I can think of other perfectly valid reasons why the USN might prefer to avoid liquid cooled engines in the 1930s, but coolant storage isn't one of them.
Cheers
Steve


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## stona (Apr 29, 2014)

OldSkeptic said:


> Correct. Everyone uses things like the the Italian landings (etc) to slag off the Seafire, but it was the only plane at the time (US and UK) that could hold it's own with a 109 of the era (not many 190s in that arena) . It wasn't perfect by any means and the UK had to use (because of idiotic shipbuilding decisions) escort carriers as 'real' carriers. And they were unlucky, slow ECs with zero wind.... whoops, but they did the job. Imagine a Wildcat vs a 109F or G of the time..... slaughter city.



The Seafire received much criticism after the Salerno landings but much was unjustified. 

It suffered a landing accident rate of just over 10%, but given the calm conditions in the Mediterranean at that time of year and the slow carriers this was inevitable. Mike Crossley describes it as a "mathematical certainty" given the Seafire's vertical touch down velocity (7 ft/sec) mandatory 3.5 degree descent path and 15 knots of wind over the deck.

It was described as not fast enough to fulfil its primary task, the interception of the Fw 190 fighter bombers over the beach head. This failing was more a matter of tactics. The Seafire LIIc certainly could catch a Fw 190 but not as they were deployed at Salerno. They flew about 500 sorties and only made 3 interceptions. This was entirely due to a lack of warning. The ships were inshore and the radar suffered ground clutter which led to little or no warning of the approach of enemy aircraft at low level. The Luftwaffe pilots were not stupid and had worked out that by keeping some high ground behind them, in line with their sea level approach, they were invisible to ship's radar at any range. The Seafires flew CAP at 240 knots, the maximum feasible speed to conserve fuel, and could not accelerate to the 350 knot diving approach speed of the Fw 190s in time. Combined with the poor visibility this enabled the Fw 190s to evade virtually every time. Crossley's view is that had the ships been further off shore, avoiding the clutter and giving warning of the approaching Fw 190s at about 20 miles the Seafires could easily have accelerated to their escape speed of about 300 knots and made more interceptions.

The only really irrefutable criticism of the Seafire is its lack of endurance. Even with a 45 gallon slipper tank it could not manage a two hour patrol, largely due to the faster patrol speed. Added issues were the inability of the carriers to maintain a straight course for any length of time during landing operations before they hit.....Italy. The number of accidents also led to delays. Inevitably pilots would ask for landing with fuel in hand, shortening patrol times.

The Seafire could have been used much better during these operations but Rear Admiral Vian was not a man who had a firm grasp of air operational tactics. As OldSkeptic points out, there were no viable alternatives.

Cheers

Steve


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## rinkol (Apr 29, 2014)

RCAFson said:


> And the RN had the Skua in service in Sept 39 while the Albacore, which was generally superior to the Devastator, was just completing it's trials and was awaiting volume production of the Taurus engine. The USN would not field a replacement for the TBD until mid 1942. The first production Fulmar flew in Jan 1940 and it would be almost another two years before the FAA received any folding wing fighters from Grumman and the F4U was not carrier qualified, even by the RN until late 1943 and not by the USN until early 1944. The RN planned to have the Firefly in service in 1941 and the Barracuda in late 41/early 42; those plans took a beating after France fell, as FAA production priorities took a distant 2nd to the RAF. I suspect that if Japan or the USA had a hostile army and airforce parked 20 miles offshore that their naval aircraft production plans would have also suffered numerous delays.
> 
> The FAA navalized both the Hurricane and Spitfire but then again, there was nothing available from the USA until mid 1943, that could match or exceed either aircraft's performance as naval fighters. In mid/late 1942 the USN was desperately trying to match the A6M's performance while the FAA was having to tackle the 109f and FW190, hence the need for Seafires.



The Albacore was about 3 years later in timing than the Devastator. Even then, with substantially less power, the Devastator was 20% faster, due at least in part to its monoplane layout. The Seafire was an unplanned improvisation - I don't doubt that it filled a real need and was the best available solution under the circumstances. Nevertheless, the RN paid a price for the fallacious belief held prior to the war that naval aircraft would operate outside the range of land based aircraft and did not need to be competitive in performance with them.


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## FLYBOYJ (Apr 29, 2014)

stona said:


> *Is there any evidence for that? It seems to be one of these things that has accrued credibility by repetition whilst being based on a fallacy, the flammability of glycol. I'm genuinely interested and would love to see some evidence to back up the contention. In the absence of any evidence it should be discounted as a reason and consigned to the myth bunker (which is bulging at the seams since the internet came into being  )*
> I can think of other perfectly valid reasons why the USN might prefer to avoid liquid cooled engines in the 1930s, but coolant storage isn't one of them.
> Cheers
> Steve


I could try to look around and find the reference but I could tell you I served in the US Navy and it was told to me on more than one occasion by guys who were around when the Skyraider was still being operated. there were other bulk liquids that were not welcomed on ships.

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## stona (Apr 29, 2014)

Well the stuff will burn, it is combustible, most things are. It seems to be a bit unlikely that this could be a genuine reason for not using liquid cooled aero engines, given some of the other materials routinely stored in large quantities on the carriers of the day 
I still think that there is an element of myth about this, though obviously something that has been believed and repeated for some considerable time.

Typical storage 'instructions'.

_"HANDLING AND STORAGE
Ethylene glycol is a stable, non-corrosive chemical with high flash point. Since it is hygroscopic, storage vessels must be designed to minimize moisture pickup. Other possible contaminants are iron and oxygen. For longer term storage, or where iron contamination and color are objectionable, resin linings or stainless steel and aluminium vessels are recommended. Linings based on phenolic and epoxy resins are satisfactory. Zinc or zinc alloys should not be used in glycol service. For longer-term color stability, it is recommended that the product be stored under an inert atmosphere.
Cast-iron or centrifugal pumps with stainless shafts and impellers are satisfactory. Rubber-lined or rubber-bound gaskets should be avoided. Flexible graphite filled or stainless steel double-jacketed gaskets are usually effective larger gaskets. Stainless steel winding with flexible graphite filler piping gaskets performs well. Pipe thread lubricants based on corrosion inhibiting zinc compounds or a graphite based lubricant with aluminum are generally satisfactory; however, glycols are excellent penetrants and leaks may be present where hydrostatic testing has
indicated a tight system. Therefore, the system should be rechecked after the glycol has been added. Low pressure stainless steel steam coils in storage tanks and steam tracing of transfer lines may need to be provided in cases where low environmental temperatures may make pumping of the product difficult. Flushing with water and steam can readily clean transfer or storage tanks."_

There is nothing difficult or complicated about that. It's probably more difficult to store aviation fuels.

Cheers

Steve


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## RCAFson (Apr 29, 2014)

rinkol said:


> The Albacore was about 3 years later in timing than the Devastator. Even then, with substantially less power, the Devastator was 20% faster, due at least in part to its monoplane layout. The Seafire was an unplanned improvisation - I don't doubt that it filled a real need and was the best available solution under the circumstances. Nevertheless, the RN paid a price for the fallacious belief held prior to the war that naval aircraft would operate outside the range of land based aircraft and did not need to be competitive in performance with them.



We could go back and forth on the Albacore versus TBD but it is a fact that the FAA was trying to introduce more modern aircraft that were competitive with IJN and USN aircraft (and IMHO the Albacore was, for a variety of reasons, superior to the TBD) but trying to match land based air by any countries carrier based aircraft was not achievable with existing engine technology until 1944 or so. The FAA, especially, was hampered by the short flight decks of their older carriers, and so required strike aircraft with much better STOL characteristics than the IJN or USN; the TBD, for example, would have been inoperable from any of the older RN carriers, and only marginal from the newer armoured carriers.

Neither the USN or IJN in Sept 1939 or Dec 1941 was equipped to go toe to toe with land based air. IJN carrier aircraft would have been regarded as completely outclassed by the RAF and Luftwaffe in Europe in Sept 39, April 1940 or Dec 1941 and judged unsuitable for combat due to their low performance, and lack of armour and SS tanks, ditto for USN carrier aircraft.


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## FLYBOYJ (Apr 29, 2014)

stona said:


> Well the stuff will burn, it is combustible, most things are. It seems to be a bit unlikely that this could be a genuine reason for not using liquid cooled aero engines, given some of the other materials routinely stored in large quantities on the carriers of the day
> I still think that there is an element of myth about this, though obviously something that has been believed and repeated for some considerable time.
> 
> Typical storage 'instructions'.
> ...



I think this comes more from the fact that if there were large amounts of a liquid aboard a carrier, it would have to be stored in a bilge and that's probably the reason why there was a resistance of this extra "bulk liquid." 

As stated, if it wasn't necessary, folks running a carrier wouldn't even want aviation fuel on board!

Something interesting on this out of Wiki - a reference from a written by Tommy Thomason on his book about the Bell XFL-1 Airabonita.

_"As a possible further reason for the rejection it is often stated that the Navy's position during that era was that all its aircraft should use air-cooled engines (while the Allison was liquid-cooled). This appears unfounded speculation. The U.S. Navy "would consider a liquid-cooled engine installation provided a material increase in performance over air-cooled engine can be shown."_

In addition to this "story or myth" on glycol on US Carriers, I was also told that one of the reasons why the Skyraider went away immediately after Vietnam was because of the storage of high octane Avgas. These comments were made by Chiefs, and those of us who were in the Navy knows you never argue with a Chief!!!!

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## rinkol (Apr 29, 2014)

FLYBOYJ said:


> I think this comes more from the fact that if there were large amounts of a liquid aboard a carrier, it would have to be stored in a bilge and that's probably the reason why there was a resistance of this extra "bulk liquid."
> 
> As stated, if it wasn't necessary, folks running a carrier wouldn't even want aviation fuel on board!
> 
> ...



The Navy did sponsor a high powered liquid cooled engine, the P&W XH-3130, during the late 1930's. This was later abandoned in favor of the R-4360. Nevertheless, it does indicate that, while the Navy may have had definite preferences, it was willing to consider other approaches if necessary.


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## GrauGeist (Apr 29, 2014)

The Navy tested a P-51 and P-51D, so they were definately open to options as far as liquid-cooled aircraft are concerned.



> These comments were made by Chiefs, and those of us who were in the Navy knows you never argue with a Chief!!!!


Try having two retired career USN Chiefs (who were also WWII/Korea combat vets) as Uncles!

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## GregP (Apr 29, 2014)

Hi Steve,

If anything is flammable, a direct hit from a 14 - 16 inch Naval gun will set it off rather instantly, or at least ignite it since armor-piercing rounds went through many layers of walls and decks before they detonated. I think they were open to a liquid-cooled aircraft if it showed itself to be clearly superior to the air-cooled variety. Not many could do that at the time (early WWII for the USA).

There was NO force likely to be encountered that could ruin your day like an accurate Naval gun salvo.

I'm not saying I agree with them, but I heard that too when in the service ... even in the Air Force, since we had Navy exchange fliers who were WWII aviation fans like we were, so it got discussed. Another factor was the pilots. If they had their choice, none of them wanted to fly liquid-cooled planes. It was said the some aviators said if they were ordered to do so on operations, they's hand in their wings. I have no reference for that since it was conversation over a meal. Possible mutiny among the aircrews is enough to make deploying a liquid-cooled unit something to consider before some were introduced at land bases where they could be proven to be OK before being deployed.


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## Shortround6 (Apr 29, 2014)

The Navy had had a lot of bad experiences with water cooled engines in the 1920s. A lot of which had very little to do with the engine itself and a lot to do with broken waterlines/piping and leaking radiators. Pure Ethylene Glycol leaks worse than plain water. It has the ability to seep through joints that are actually water tight. 
Piping, joints, couplings and radiators all got better during the late 20s and 30s but the Officers making the decisions in the late 30s early 40s may have been the same guys ( or from the same class) as the guys who had to ditch and be fished out of the water (hopefully) due to water leaks back in the 20s. 
The storage "problem" _may_ have been the final straw or nail in the coffin in the argument. I doubt it was the _only_ reason for staying away from liquid cooled planes. By about 1940 Both the Merlin and Allison had moved back from pure Ethylene Glycol to mixes of Ethylene Glycol and water which were much easier to seal up.


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