# Navalized P-38/39/40: pros cons



## tomo pauk (Sep 24, 2015)

Would it be good for Allied cause if there were such aircraft developed, produced deployed? By navalized P-39 I don't mean the Airabonita.


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## rank amateur (Sep 24, 2015)

Would a P38 be able to take off on such short a distance as an aircraftcarriers' deck?


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## tomo pauk (Sep 24, 2015)

The P-38 featured Fowler flaps, that meant the take off, landing and generally low speed capabilities would be favorable. The take off power, even with early engines, is 2300 HP total, 15% greater than F6F or F4U-1.


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## T Bolt (Sep 24, 2015)

I think coming up with an aresting hook that would work with the twin boom design of the P-38 might be difficult

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## rinkol (Sep 24, 2015)

There are several big issues:

- the relatively large wing span adversely impacts the ability to maximize the storage of aircraft on a carrier. A significant difference would still exist even if a folding wing mechanism were fitted. 
- the liquid cooled engines would complicate maintenance - you would be introducing a type of engine that is both different from and more complex than the air cooled engines used by all other deployed aircraft deployed on a carrier
- the throttle response of the turbocharged engines is an issue, particularly on landing (this is presumably one of the reasons why the US Navy completely avoided the use of turbochargers). Conversely, the operational requirements of the time emphasized low and medium altitude performance where the turbochargers were of little or no benefit.
- the wing loading is relatively high and would be increased by the addition of naval equipment 
- an engine failure would have serious consequences on either take-off or landing (this is a situation where you are probably better off with one very reliable engine rather than two engines of lower reliability and/or greater vulnerability to combat damage.)
- the cost is almost certainly considerably higher

I would submit that the US Navy was well served by The F6F and F4U and had no reason to change things.

Robert


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## soulezoo (Sep 25, 2015)

rinkol said:


> I would submit that the US Navy was well served by The F6F and F4U and had no reason to change things.




This...^^^^

P-40 or even P-39 vs F4F maybe you can make an argument. Would the differences and any advantages really outweigh what was done historically. I really don't think so.


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## FLYBOYJ (Sep 25, 2015)

Stores Chiefs would hate to have a bilge made just to store glycol!

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## Elmas (Sep 25, 2015)

I think that not only Store Chiefs, but all the crew, from the Commander downwards, had their nightmares storing gasoline...... let it alone to store glycol, in addition.


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## GrauGeist (Sep 25, 2015)

Not sure why we're comparing early AAC/AAF aircraft to mid-war USN aircraft...

In any case, the P-40 and P-39 did not have the range of the F4F (845 miles): P-40 - 650 miles, P-39 - 525 miles and while the P-38 had an impressive range of 1,300 miles, the P-38 is simply not suitable for carrier ops.

The P-40 and P-39 also would have needed some structural modifications, like stronger main gear for landings, tail structure mods for allowing the shock of the arresting proceedure and of course, modifications for folding wings, which would complicate things, as the fuel tanks and armament may need to be re-arranged for that.

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## blueskies (Sep 28, 2015)

GrauGeist said:


> the P-38 is simply not suitable for carrier ops.



Lockheed didn't seem to agree


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## BiffF15 (Sep 28, 2015)

BlueSkies,

Very interesting, had not seen or heard of that before. It would be interesting to know what it's single engine performance would have been around the boat.

Cheers,
Biff


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## GrauGeist (Sep 28, 2015)

blueskies said:


> Lockheed didn't seem to agree


The U.S. Navy had 4 F-5Bs (FO-1), used exclusivly from land bases.

Regarding Lockheed's model 822 proposal, the U.S. Navy didn't want such a large aircraft, regardless of Lockheed's proposal for folding wings, strengthened tail structure tailhook, so the model 822 never left the drawing board.

Keep in mind that with liquid-cooled engines or radial engines, the model 822 would present several problems. First of which, is the "handed" engine requirement. If an engine is damaged on the 822, it can't be swapped for any engine, it has to be either a right-hand engine or a left-hand engine, so this increases the need for more engine reserves and nessecary parts specific to each engine. Also, the Navy did not want to dedicate additional room on already cramped carriers, for ethylene glycol storage. Also, the 822 would also take up more space on the deck as well as below, reducing the available number of fighters the carrier needed to have on hand.

The Navy also felt that the 822 may be problematic for launches and was too heavy for safe recovery, as the P-38 was over 7,000 pounds heavier than the F4F, 3,000 pounds heavier than the F6F.


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## GregP (Sep 28, 2015)

The stall speed wasn't really near Naval requirments, either. It could have been made to meet the requirments, but the wings would have gotten bigger.

Power off, the P-38J stalled at 99 mph with gear and flaps up. Power on it stalled at 78 mph with gear and flaps down. Power on it stalled at 53 mph with gear and flaps down. The 53 mph SEEMS OK until you realize it was at 54" MAP and 3,000 rpm ... hardly an approach configuration. The F6F Hellcats typically stalled in Landing Configuration at 78.5 knots or 90 mph, but also they weighed a LOT less than a P-38. Getting s a plane more than 5,000 pounds heavier stopped in the cat stroke mikght have been interesting from the point of vbiew of where the stress from the hook would be distributed in the P-38 airframe.

From an energy standpoint, the P-38 has some 41 more mass and only takes about 6% more energy to stop, but the stress has to be collected somewhere in the airframe or the hook pulls out. By comparison with the P-38, the Hellcat was cheaper by far, available, MUCH easier to produce, and would result in more aircraft stored in the same space and burn less fuel for a slight drop in performance in top speed and climb, but an advantage in turn ability and stall resistance. The advantage was all Hellcat in gasoline usage, and the P -38 also used Glycol coolant. The P-38 had good centerline arramanet. The F6F Hellcats six 50's were't too far behind, and all the F6F guns had the same trajectories. The cannon in the P-38 had different ballistic chraracteristics than the MG armament did, so if one was hitting, the other was missing except at short range.

I love the Allison but, if given a choice for flight off a carrier, I'd opt for the Hellcat any day of the week.

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## stona (Sep 28, 2015)

Elmas said:


> I think that not only Store Chiefs, but all the crew, from the Commander downwards, had their nightmares storing gasoline...... let it alone to store glycol, in addition.



Why? Take a look at the physical properties of ethylene glycol. It is a benign chemical, not particularly toxic, with a flash point of 111 degrees Celsius (compared with around -45 for petrol/gasoline). It freezes at -13 degrees Celsius and heating coils maybe installed in outside tanks exposed to very low ambient temperatures! It is most often stored in regular mild steel drums.

I keep seeing the difficult/dangerous to store argument against the storage of glycol on board aircraft carriers, but it is entirely spurious.

Cheers

Steve (putting on his rather old chemist's hat)


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## gumbyk (Sep 28, 2015)

stona said:


> Why? Take a look at the physical properties of ethylene glycol. It is a benign chemical, not particularly toxic, with a flash point of 111 degrees Celsius (compared with around -45 for petrol/gasoline). It freezes at -13 degrees Celsius and heating coils maybe installed in outside tanks exposed to very low ambient temperatures! It is most often stored in regular mild steel drums.
> 
> I keep seeing the difficult/dangerous to store argument against the storage of glycol on board aircraft carriers, but it is entirely spurious.
> 
> ...



Take a look at the difficulties of extinguishing it once it is ignited: 




(from the CDC website)


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## GrauGeist (Sep 28, 2015)

stona said:


> I keep seeing the difficult/dangerous to store argument against the storage of glycol on board aircraft carriers, but it is entirely spurious.


I think people are under the misconception that "coolant" is a hazard, and that's actually not the case, as the only thing hazardous about coolant, is that it will kill you if you try and drink it (even if it's strained through a loaf of french bread).

The Navy's argument against bringing liquid-cooled aircraft into the inventory, was that creating storage space for ethylene glycol would rob them of precious storage space for hydraulic fluid, oil, gasoline and other liquids necessary to keep the aircraft committed to battle. 

Having one or so liquid-cooled aircraft aboard may not seem like such a big deal, but if your entire compliment were all liquid-cooled, you'd need to have a great deal of storage for coolant. For example: a P-51D has a total coolant capacity of 21.5 gallons (16.5 - engine/5.0 - After Cooling System), a P-38 has a much greater capacity.


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## stona (Sep 28, 2015)

gumbyk said:


> Take a look at the difficulties of extinguishing it once it is ignited:



You could say the same thing about a lot of materials on an aircraft carrier. Glycol can be diluted with water to a non combustible liquid, something you can't say for petrol or oils. You can't generally spray water on to an oil/petrol fire either, you'll just spread it. Special nozzles were eventually developed that did enable water to be used, but it took the loss of the USS Lexington (to re-ignited gasoline fires) before the 'Rockwell nozzle' became generally available. The above is not an argument against storing glycol. The space issue may be a valid argument, but not the hazard. Gasoline and other oils present a far greater hazard and the navy was obliged to store them if it wanted to operate any aircraft.

Cheers

Steve


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## GregP (Sep 29, 2015)

There is not much of a problem storing glycol. All it takes is a tank. Add one anywhere when the carrier is built and you have it.

But glycol means you need the glycol itself, a radiator cap, a water pump and, at minimum, 3 or more hose connections to the engine to make it flow. So you have 6 hose ends minimum, a cap, a radiator and a pump to fail, adding maybe 20 more ways to fail. Each hose could fail due to a hose clamp on either end or the hose itself, the pump can leak at either connection, lose a blade or blades or lobe if positive displacement type, or a bearing, the radiator cap can either leak or fail pressure, the radiator can leak at the in and out connections or in any of the cores, and it can also get plugged up in mmany more than one place and cause issues as a result. The coolant can always fail over time and simply not cool well enough. The entire system can be fine and still suffedr battle damage rendering the cooling system inoperable.

I've always thought the Navy wanted air-cooled radials mainly to cut down on possible failure modes in piston engine cooling systems.


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## GrauGeist (Sep 29, 2015)

I recall reading an overview of the Navy's decision to keep radials as the primary power source for thier aircraft because they didn't want to convert existing carrier storage and didn't intend to modify current designs for carriers being planned/built.

There was also mention of the "old school" train of thought that the radial was more reliable and while I disagree about reliability over extended hours on the engine, I will agree that the radial is far more tolerant to battle damage (as seen with both Army and Navy radials)

There was also an interesting point made, that the coolant lines were considered weak points and subject to a potential failure with the violent landings.

This is not to say that the Navy didn't consider liquid-cooled fighter aircraft, for example, the Navy had evaluated several P-51 aircraft over the years, starting with "Project Seahorse" and a P-51 [41-37426], then a P-51D (ETF-51D) [44-14017] and even later, with a pair of P-51Hs [44-64420/44-64700], leading North American to propose the NAA-133 project.

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## Conslaw (Sep 29, 2015)

GrauGeist said:


> The U.S. Navy had 4 F-5Bs (FO-1), used exclusivly from land bases.
> 
> Regarding Lockheed's model 822 proposal, the U.S. Navy didn't want such a large aircraft, regardless of Lockheed's proposal for folding wings, strengthened tail structure tailhook, so the model 822 never left the drawing board.
> 
> ...



I recognize all these difficulties in adapting the P-38 for naval service, still I can imagine small quantities of naval P-38s being used for special strike missions, Fast bombers to go after high value, defended targets. Imagine if you will, a Doolittle II type strike.


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## tomo pauk (Sep 29, 2015)

Cheers, Dave,



GrauGeist said:


> ...In any case, the P-40 and P-39 did not have the range of the F4F (845 miles): P-40 - 650 miles, P-39 - 525 miles and while the P-38 had an impressive range of 1,300 miles, the P-38 is simply not suitable for carrier ops.



The range figure of 850 mi for the F4F-3 (= no drop tank) is for 160 mph cruise at 5000 ft. Speed up to more realistic requirements, say 15000 ft and 250 mph and we have 600 miles? The P-40 was less draggy than F4F, with no less fuel, and will make better range out of it.
Stating out that 'P-38 is simply not suitable for carrier ops' is a applying too wide a brush, both USN and RN operated far clumsier aircraft from their CVs during ww2.



> The P-40 and P-39 also would have needed some structural modifications, like stronger main gear for landings, tail structure mods for allowing the shock of the arresting proceedure and of course, modifications for folding wings, which would complicate things, as the fuel tanks and armament may need to be re-arranged for that.



Neither P-40 nor P-39 would need any change to fuel tanks. Granted, it would took rework on the wing and tail on all of the proposals to make them into 'SeaFighters'.



GrauGeist said:


> ...
> Regarding Lockheed's model 822 proposal, the U.S. Navy didn't want such a large aircraft, regardless of Lockheed's proposal for folding wings, strengthened tail structure tailhook, so the model 822 never left the drawing board.



Again - the USN operated even bigger A/C. Do we know for sure what USN though of the proposal?


> Keep in mind that with liquid-cooled engines or radial engines, the model 822 would present several problems. First of which, is the "handed" engine requirement. If an engine is damaged on the 822, it can't be swapped for any engine, it has to be either a right-hand engine or a left-hand engine, so this increases the need for more engine reserves and nessecary parts specific to each engine. Also, the Navy did not want to dedicate additional room on already cramped carriers, for ethylene glycol storage. Also, the 822 would also take up more space on the deck as well as below, reducing the available number of fighters the carrier needed to have on hand.



Hmmm - whose requirement was for the Lockheed's fighter to have handed engines - USN's or Lockheeds? Eg. USAF insisted on handed engines for their P-38s (also for the non-turbo variants used for training). Granted, the navalized P-38 will take up more space than a S/E fighter, even a big one, but we can recall that many, if not most of the naval aircraft did not featuring much of the folding wings in the 1st place.



> The Navy also felt that the 822 may be problematic for launches and was too heavy for safe recovery, as the P-38 was over 7,000 pounds heavier than the F4F, 3,000 pounds heavier than the F6F.



The TBF-1 weighted 14360 lbs in 'scout' configuration (internal fuel only, no bombs/torpedo), and above 17300 lbs with torpedo and two drop tanks, and even in that configuration can take off from a carrier.


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## GrauGeist (Sep 29, 2015)

tomo pauk said:


> whose requirement was for the Lockheed's fighter to have handed engines - USN's or Lockheeds? Eg. USAF insisted on handed engines for their P-38s (also for the non-turbo variants used for training).


It was a design requirement by Lockheed in order to achieve successful flight characteristics. During the development stage (model 22 - XP-38), it was found that "handed" engine rotation solved some dangerous tendencies and at first, they discovered that the engine's were installed "backwards", robbing the P-38 of necessary lift to take off...this was corrected by swapping the engines.



tomo pauk said:


> Granted, the navalized P-38 will take up more space than a S/E fighter, even a big one, but we can recall that many, if not most of the naval aircraft did not featuring much of the folding wings in the 1st place.


The only two USN aircraft that did not have folding wings, were the Brewster F2A and the Douglas SBD.

Also, consider that the P-38's wingspan is 52 feet (15.8m) and not designed for low-speed stalls. The solution to that, would be to increase the wing's area to create better lift for ship-board landing and take-off. In addition, a folding wing would add more weight to the aircraft - either modification would ultimately impair it's performance and range.



tomo pauk said:


> The TBF-1 weighted 14360 lbs in 'scout' configuration (internal fuel only, no bombs/torpedo), and above 17300 lbs with torpedo and two drop tanks, and even in that configuration can take off from a carrier.


The P-38's weight and high landing speed requirements would be more than the carrier could handle at the time. The heavier attack aircraft had much lower stall speeds, and a rugged design that allowed them to violently drop onto the deck and be arrested without damage to the airframe or ship's equipment. 

I agree that the Avenger was heavy and it had a large wingspan (54 feet - 16.5m), however it's wings folded for storage. The SB2C was heavy as well, with a folding wingspan of 49 feet (15m) however, the point being, that with limited space aboard a typical USN carrier of the time, they had to find a balance of space for fighters and attack aircraft.

So in order to accommodate a navalized P-38, they would have to decide on fewer fighters or fewer attack aircraft in order to fit the ship's compliment on board.


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## tomo pauk (Sep 29, 2015)

> GregP said:
> 
> 
> > The stall speed wasn't really near Naval requirments, either. It could have been made to meet the requirments, but the wings would have gotten bigger.
> ...


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## GrauGeist (Sep 29, 2015)

tomo pauk said:


> The P-38 did not used Glycol coolant.


Tomo, the P-38 did use an ethylene glycol coolant, as the V-1710 Allisons were liquid cooled and were the same engine series as used on the P-39 and P-40 (and P-51/A-36).


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## tomo pauk (Sep 29, 2015)

GrauGeist said:


> It was a design requirement by Lockheed in order to achieve successful flight characteristics. During the development stage (model 22 - XP-38), it was found that "handed" engine rotation solved some dangerous tendencies and at first, they discovered that the engine's were installed "backwards", robbing the P-38 of necessary lift to take off...this was corrected by swapping the engines.



The Lightning I (the fighter for the RAF) have had same-rotation engines and flew well. 



> The only two USN aircraft that did not have folding wings, were the Brewster F2A and the Douglas SBD.



The F4F-3 and Douglas TBD were also without folding wings, and we can recall that Sea Hurricane, number of Zero variants and 'hooked Spitfire' were also without folding wings. The wings on other Zeroes and all of the Vals only folded at wing tip. 



> Also, consider that the P-38's wingspan is 52 feet (15.8m) and not designed for low-speed stalls. The solution to that, would be to increase the wing's area to create better lift for ship-board landing and take-off. In addition, a folding wing would add more weight to the aircraft - either modification would ultimately impair it's performance and range.



As in above post, the P-38 was 'stall-friendly' aircraft as much as possible. You may check out the 'America's hunderd thousand' P-38 entry. The Fowler flaps were great an asset of the P-38 for low-speed flight maneuvering.
The folding wing and other carrier modification will cost in increased weight, with mostly RoC suffering.


> The P-38's weight and high landing speed requirements would be more than the carrier could handle at the time. The heavier attack aircraft had much lower stall speeds, and a rugged design that allowed them to violently drop onto the deck and be arrested without damage to the airframe or ship's equipment.



The P-38 have had low stall speed, it was lower than Avenger or Corsair that were in the pipeline before Pearl Harbor. P-38 have had shortcomings, but the landing-gear-related ones were not among these, otherwise we would not be seeing the P-38 with 2 torpedoes or two 310 gal tanks attached.



> I agree that the Avenger was heavy and it had a large wingspan (54 feet - 16.5m), however it's wings folded for storage. The SB2C was heavy as well, with a folding wingspan of 49 feet (15m) however, the point being, that with limited space aboard a typical USN carrier of the time, they had to find a balance of space for fighters and attack aircraft.
> 
> So in order to accommodate a navalized P-38, they would have to decide on fewer fighters or fewer attack aircraft in order to fit the ship's compliment on board.



The proposed Lockheed Model 24 (with folding wings and V-1710s) was to feature folding wings, the wing span being 31 ft something in this case. Granted, not as 'thin' as S/E aircraft with folding wings, but not that horrible either.


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## tomo pauk (Sep 29, 2015)

GrauGeist said:


> Tomo, the P-38 did use an ethylene glycol coolant, as the V-1710 Allisons were liquid cooled and were the same engine series as used on the P-39 and P-40 (and P-51/A-36).



Glycol ethylene was a part of coolant liquid of the V-1710, the main part being water - 70% vs. 30%. Similar was true for Merlin. The V-1710 was found to run well with water being 100% of coolant. 
Early examples of the V-1710 used 97% glycol, though.


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## Conslaw (Sep 29, 2015)

tomo pauk said:


> > The stall speeds were depending on the aircraft weight. At 15000 lbs (= no drop tanks, much of the internal fuel ammo used up), gear and flaps down and with power off, the P-38H/J stalled at 69 mph. The F4U-4, under same conditions and 'no fuel', stalled at 74 kts minimum (85 mph).; 'power on' it was 67 kts. So there is next to no evidence that too high a stall speed will cancel the P-38 from USN view.
> >
> >
> >
> ...


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## blueskies (Sep 29, 2015)

GrauGeist said:


> The U.S. Navy had 4 F-5Bs (FO-1), used exclusivly from land bases.
> 
> Regarding Lockheed's model 822 proposal, the U.S. Navy didn't want such a large aircraft, regardless of Lockheed's proposal for folding wings, strengthened tail structure tailhook, so the model 822 never left the drawing board.
> 
> ...



Where are you getting this from? Because you seem to be off base on several points.

BuAer sent out a specification for a single seat, twin engined interceptor with an emphasis on rate of climb in 1938. This tender was ultimately won by the Grumman G-34 (xf5f).

So where are you getting this idea that the navy didn't want something like what lockheed submitted?

Now Lockheed had two variants of the P-38 submitted to this tender, the Model 24A and Model 24W. The A was allison powered, but the W was an R-1535b (incidentally grumman submitted an allison powered alternative of its g-34 to this same tender.)

If you look at the specs for the radial engined Model 24w, you will find that it is at 9000lbs gross (which is not 7000 more than an f4f), and the allison powered 24a was 10500lbs (also a long way from being 7000lbs more than an f4f) Are you making the mistake of looking at late war p-38s figures?

The issue of coolant is a complete non-issue with the radial variant, and given the Navies preference for radials, I wouldnt bother to debate the issues pertaining to it 

Regarding the handed engine, do you know if it was a reduction gear swap or not with the R-1353?

It was also estimated by Lockheed that the 24w would have a landing speed of 65.3mph. Now mind to compare that to an f4f?

EDIT: the R-1535s used on the xf5f had handed reduction gear, so I don't see why they couldn't be used on the 24w


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## GrauGeist (Sep 29, 2015)

tomo pauk said:


> Glycol ethylene was a part of coolant liquid of the V-1710, the main part being water - 70% vs. 30%. Similar was true for Merlin. The V-1710 was found to run well with water being 100% of coolant.
> Early examples of the V-1710 used 97% glycol, though.


Tomo, I'm not sure where you've gotten that information, but Allison recommends the 70/30 mix and I have never seen anything to the contrary.

Running a coolant content of 97% glycol and 3% water is very questionable, as nearly pure glycol in the system reduces the cooling system's effictiveness by 35%, as the coolant needs the water to facilitate the transfer of heat.

On the otherhand, running pure water in the system, even pressurized, eliminates the lubrication of the water pumps and lowers the boiling point by quite a bit.

Neither of these (pure water or 97% coolant) would have been done on a P-38 (or any other warplane for that matter) as it would have compromised the aircraft and pilot.


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## tomo pauk (Sep 30, 2015)

The data is from 'Vee's for victory'. The pure water was stated as 'the best coolant' there. However, for low temperatures of Alaska, where the V-1710-G6 (in Twin Mustang) was operating, the mixture was 70% Glycol, 30% water, with a note that max allowable inlet temperatures are decreased in that case.



Conslaw said:


> The P-38s of 1941 were not really combat ready. The first squadron-sized P-38 combat didn't occur until late 1942 in North Africa and in the South Pacific. P-38s were in high demand and short supply for most of the war. In fact, General Kenney couldn't get as many as he wanted well into 1945. (It is ironic, though, that many of the P-38s delivered in 1945 were delivered straight from the factory to the boneyards.)



Lockheed proposed the Model 24 to the USN in 1937. If Navy agrees, Lockheed can start with production of the prototype in reasonable time, and then, if/when it is judged carrier-capable, with preparations for series production. That way we, hopefully, negate the effect of the 22 months (!) long hiatus between the contracts for XP-38 and YP-38, so the Army too can have their P-38s a bit faster. 
Granted, farming out the production of Hudsons and similar can help out with production speed, as it is true with second source ASAP (instead of in 1945), or even 3rd.

I'd like to see the reasoning with saying that P-38s of 1941 were not combat ready. The P-38D have had self-sealing fuel tanks (something that feared Zero never got) and full protection for pilot (we can again compare this with IJN/IJA aircraft that scourged Allied AFs during the opening phase of Pacific war).




> The Corsair flew its first combat missions from Guadalcanal in February 1943, just 3 months after the P-38. Roughly 3 months later the F6F was available, and Grumman was able to deliver them fast enough to supply the new carriers coming on duty from mid-1943 through late 1944. At that point they increased Kamikaze menace caused fighter complements to rise to over 70 fighters per carrier, and F4U Corsairs were used to supplement the F6Fs.



With timely response to the Lockheed's proposal, Navy can have the P-38s in 1941, and in 1942 can have them in strength; the F6F will have to wait mid 1943 at best. The P-38 will climb far better than either F6F or F4U (only P-63 beating it, of all US ww2 service fighters?), will have greater endurance so it can beter respond to aerial threats, longer shooting time, along with greater range/radius for offensive ops.

The F4U have had almost no visibility for carrier landing, higher stall speed, bad/dangerous low speed handling - no match for docile P-38. The F4Us that flew on Valentine's day were Marine's aircraft that operated from ground base, it will took precious time and veteran pilots for the F4U to be a real carrier bird.


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## gjs238 (Sep 30, 2015)

tomo pauk said:


> The data is from 'Vee's for victory'. The pure water was stated as 'the best coolant' there. However, for low temperatures of Alaska, where the V-1710-G6 (in Twin Mustang) was operating, the mixture was 70% Glycol, 30% water, with a note that max allowable inlet temperatures are decreased in that case.
> 
> 
> 
> ...



Sounds like it could have been the Tomcat of WWII.

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## wuzak (Sep 30, 2015)

What of the turbos?

The navy weren't too keen on them.

Would teh P-38 have enough performance for naval operations without them?


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## FLYBOYJ (Sep 30, 2015)

GregP said:


> There is not much of a problem storing glycol. All it takes is a tank. Add one anywhere when the carrier is built and you have it.


Not that simple - it's Hazmat and even during the 1930s the "Black Shoe" Navy recognized this. Every bit of room aboard a ship is considered and accounted for, especially if that liquid could present a hazard. If it was up to some avgas wouldn't be carried aboard aircraft carriers (although we know unpractical).


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## FLYBOYJ (Sep 30, 2015)

blueskies said:


> Where are you getting this from? Because you seem to be off base on several points.
> 
> BuAer sent out a specification for a single seat, twin engined interceptor with an emphasis on rate of climb in 1938. This tender was ultimately won by the Grumman G-34 (xf5f).
> 
> So where are you getting this idea that the navy didn't want something like what lockheed submitted?



The P-38 was developed from an Army Air Corp proposal (X-609) Lockheed proposed a carrier-based Model 822 version of the Lightning for the United States Navy. The Model 822 would have featured folding wings, an arresting hook, and stronger undercarriage for carrier operations. The Navy was not interested, as they regarded the Lightning as too big for carrier operations although the Navy operated 200 land based FO-1, a recon version of the P-38J. The XF5F was promising but the Navy (in the early 1940s) realized that a twin engine aircraft would have been more difficult to support.


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## blueskies (Sep 30, 2015)

FLYBOYJ said:


> The P-38 was developed from an Army Air Corp proposal (X-609) Lockheed proposed a carrier-based Model 822 version of the Lightning for the United States Navy. The Model 822 would have featured folding wings, an arresting hook, and stronger undercarriage for carrier operations. The Navy was not interested, as they regarded the Lightning as too big for carrier operations although the Navy operated 200 land based FO-1, a recon version of the P-38J. The XF5F was promising but the Navy (in the early 1940s) realized that a twin engine aircraft would have been more difficult to support.



Amd that doesn't answer my question.

Where are your sources for this?

Because the aircraft I posted was the radial version of the model 24, which Lockheed submitted to BuAer spec SD 112.14 which called for a single seat fast climbing interceptor, with a preference for twin engine.

The model 822 you speak of is a later navalized p-38 proposal, not directly related to this 1937/38 proposal, other than having the same family lineage.

And there is much more to the xf5fs cancellation then you lead on to.

Although if you have sources that contradict the above, especially primary sources, then I'd love to see it.


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## GrauGeist (Oct 1, 2015)

blueskies said:


> Where are you getting this from? Because you seem to be off base on several points.
> 
> BuAer sent out a specification for a single seat, twin engined interceptor with an emphasis on rate of climb in 1938. This tender was ultimately won by the Grumman G-34 (xf5f).


And...so a single XF5-F means...what?



blueskies said:


> So where are you getting this idea that the navy didn't want something like what lockheed submitted?


Let me see...how many of these Lockheed aircraft did the Navy have built and placed into service?

Hmmm....?



blueskies said:


> Now Lockheed had two variants of the P-38 submitted to this tender, the Model 24A and Model 24W. The A was allison powered, but the W was an R-1535b (incidentally grumman submitted an allison powered alternative of its g-34 to this same tender.)
> 
> If you look at the specs for the radial engined Model 24w, you will find that it is at 9000lbs gross (which is not 7000 more than an f4f), and the allison powered 24a was 10500lbs (also a long way from being 7000lbs more than an f4f) Are you making the mistake of looking at late war p-38s figures?


It appears that in your haste to look like an ass, you missed where I used the figures for the *MODEL 822*



blueskies said:


> The model 822 you speak of is a later navalized p-38 proposal, not directly related to this 1937/38 proposal, other than having the same family lineage.


But we were speaking about the model 822 and it just so happens to be related to the model 24, as Lockheed tried to revive the concept.



blueskies said:


> And there is much more to the xf5fs cancellation then you lead on to.


The XF5-F project was cancelled because Grumman was ramping up production of current Navy contract aircraft and the XF5-F proved to be problematic with parts acquisition and production logistics. The concept was not lost on the Navy, however, as the XF5-F led to the development of the F7F. 



blueskies said:


> Although if you have sources that contradict the above, especially primary sources, then I'd love to see it.


I am pretty sure you're able to read the same literature as we are...perhaps you should give it a try...


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## blueskies (Oct 1, 2015)

GrauGeist said:


> And...so a single XF5-F means...what?




That a twin engine aircraft, of quite similar weight to the model 24, won the BuAer tender.



> Let me see...how many of these Lockheed aircraft did the Navy have built and placed into service?
> 
> Hmmm....?



I thought I made it clear enough that the 24 lost the tender to the G-34. No need for snark.




> It appears that in your haste to look like an ass, you missed where I used the figures for the *MODEL 822*



You quoted my post, with a drawing of the 24w, and went off on tangent about the much later 822. 

I dont exactly see why you would change the subject to a design of some 3-4 years later, submitted in a different atmosphere to a different tender, with a different engine, all while quoting my post.

Do you see how that could be an honest mistake? Because it genuinely seemed like you were confusing a much later attempt with a very little known earlier tender.

And where are your figures for the 822? All you posted were some stats of how much more it would weigh then a few other aircraft.



> But we were speaking about the model 822 and it just so happens to be related to the model 24, as Lockheed tried to revive the concept.



And you brought up the 822 in response to my post about the model 24, and listed several reasons why the 822 was rejected that have nothing to do with the 24w.



> The XF5-F project was cancelled because Grumman was ramping up production of current Navy contract aircraft and the XF5-F proved to be problematic with parts acquisition and production logistics. The concept was not lost on the Navy, however, as the XF5-F led to the development of the F7F.



Mostly there. The xf5-f lead to a sort of joint development program with the army, but the divergent requirements slowed down work on the naval version and possibly lead to some animosity with the navy (ie, army requirements were getting more engineering attention then naval)

Thus BuAer put out another tender for a twin carrier fighter, with the contract being awarded to grumman before the xf5f was official killed - which I think you can agree is different from what flyboy asserted.




> I am pretty sure you're able to read the same literature as we are...perhaps you should give it a try...



Yes that is quite true.

But what you and flyboy wrote about the 822 are near verbatim quotes of a short bit of text on the 822 that is plastered on dozens of sites, including wikipedia. The problem is none of these sites giive a source or attribution for that text. So do you have an original source for that 822 info, or are you just going off a website?

Because often times frequently repeated bits of ww2 aviation "fact" turn out to little more then half truths or outright falsehoods - which is why I am generally skeptical of anything without primary source documentation.

And there is no reason to curse ir get bent oht of shape. I think you misunderstood my tone and took things a bit personally when no such intention was there.

No point in getting angry over discussing half+ century old airplane. Lord knows there are more important things to get angry about.

S!


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## GregP (Oct 1, 2015)

About the glycol, it was that simple Joe. If you fly liquid-cooled aircraft, you carry coolant. If you don't want to carry coolant, you don't fly liquid-cooled aircraft. Hazmat wasn't much of threat in the 1940's and the term wasn'tr even known or used at the time ... as you well know. Glycol pales as Hazmat when compared with ordnance and aviation fuel.

My grandfather was of the WWII generation and wasn't concerned about hazmat at all, ever. He used what he needed and stored what he needed on his farm, including glycol for the tractors. Most of the WWII generation I've met never even mentioned hazards from materials ... except how to handle it. It was just part of the game. You didn't carry a load of gasoline around unless it was necessary and, if it was, you carried it. That simple.

It wouldn't be that simple today, granted ... but in WWII it was. As I've stated before, my belief is they didn't go for Naval liquid-cooled planes due to the additional chances for failure and losses from the addition of the liquid-cooled engine and associated systems and hoses.

I have heard several very senior Naval officers say that same thing but, hey, they could be wrong.

But it also wasn't a big deal since they rapidly went from pistons to jets after the war and then had the additional hazard of storing hydraulic oil in unprecedented quantities since jets had primary hydraulic systems even as early as the F-86 / FJ-2/3. Prior to jets, the hydraulic systems were mostly for the landing gear and wing fold systems (small volumes), not the main controls and the backups, too. So the quantities of red oil were much less than after jets came along.

We have a Bell YP-59A. The gear folds hydraulically (not the gear doors) but the flaps are electric and most of the rest of the plane is electric. The plane they transitioned to from the P-59 was the P-80, and it was all hydraulic as far as I know, and pretty much stayed that way from then on.


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## FLYBOYJ (Oct 1, 2015)

blueskies said:


> Amd that doesn't answer my question.
> 
> Where are your sources for this?



Bodie, Warren M. The Lockheed P-38 Lightning: The Definitive Story of Lockheed's P-38 Fighter. And it also helped that I actually worked there during the 1980s and knew some of the folks responsible for developing the P-38


blueskies said:


> Because the aircraft I posted was the radial version of the model 24, which Lockheed submitted to BuAer spec SD 112.14 which called for a single seat fast climbing interceptor, with a preference for twin engine.



The 1937 Model 24 went no where - it was a proposal submitted to the USN and it went no further. Do you have a drawing source for your photo of the model 24 proposal becaue it looks VERY fishy!!!










blueskies said:


> The model 822 you speak of is a later navalized p-38 proposal, not directly related to this 1937/38 proposal, other than having the same family lineage.



the 822 was offered up early in the war. From what I could see there was little difference from the model 24 at least on paper were both proposals lived and died.


blueskies said:


> And there is much more to the xf5fs cancellation then you lead on to.


So I'm told...


blueskies said:


> Although if you have sources that contradict the above, especially primary sources, then I'd love to see it.



There's many articles, books, papers written by folks like Bodie, Miller, and even from Lockheed publications that stated the US Navy showed little interest in the P-38. Just because Lockheed replied to a proposal from the navy doesn't mean they were soliciting Lockheed to investigate a radial engine navalized P-38 and there's nothing showing that Lockheed was interested in developing this proposal on their dime. Now I'm not going to search far and wide for this stuff but I think history tells us this outcome is quite evident and again I'll repeat I worked at the old Burbank plant in some of the very same buildings where the P-38 was built with some of the same folks who worked production lines and flight test. If that's not good enough for you so be it, you're entitled to your own opinions and views...


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## FLYBOYJ (Oct 1, 2015)

GregP said:


> About the glycol, it was that simple Joe. If you fly liquid-cooled aircraft, you carry coolant. If you don't want to carry coolant, you don't fly liquid-cooled aircraft. Hazmat wasn't much of threat in the 1940's and the term wasn'tr even known or used at the time ... as you well know. Glycol pales as Hazmat when compared with ordnance and aviation fuel.
> 
> My grandfather was of the WWII generation and wasn't concerned about hazmat at all, ever. He used what he needed and stored what he needed on his farm, including glycol for the tractors. Most of the WWII generation I've met never even mentioned hazards from materials ... except how to handle it. It was just part of the game. You didn't carry a load of gasoline around unless it was necessary and, if it was, you carried it. That simple.
> 
> ...



Greg - talk to guys who served aboard ships and they'll tell you a whole different story. Bilges are well thought out and planned as storage of liquids. I was told that at one time some fuel and water bilges were actually shared to save space!


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## GregP (Oct 1, 2015)

In most carriers water was let into the fuel bilges for ballast because fuel floats on the water. It works except in violent seas when flying wouldn't be happening anyway. I realize bilges are planned out. What I was saying is simply that if they wanted to emplane liquid-cooled aircraft, they'd have to allow bilge space for coolant ... or space above the bilges, and I cannot see a way around that statement.

You can't fly liquid cooled planes and expect the same coolant they emplane with to be used for the entire cruise. They lose some due to leaks and they also loose some due to maintenance. You MUST be able to replace it so the plane can fly.

Ergo, had they acquired any liquid-cooled aircraft on carriers, they'd HAVE to have coolant aboard somehwere, whether in bilges or not. I'm not arguing about where it would be stored or what procedures would be required. All I'm syaing is the coolant would be required; it would not be optional.

Maybe coolant did play a part in the Naval preference for air-coold radials. I wasn't around to hear the arguments, but have heard that the guys making the decisions were biased toward air-cooled radials because that's what THEY flew when engine becames much more reialble during their earlier flying careers. Again, these stories might be wrong, but they do get repeated occasionally at museum events by guys who were there. Maybe it ws all scuttlebutt. Maybe not. I don't recall ever having heard anyone who flew the Wildcat / Hellcast / Bearcat saying they weren't great aircraft. Everyone who flew them loved them.

Of course, you could say the same about Spitfires and Bf 109s, too, and a host of others.


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## FLYBOYJ (Oct 1, 2015)

GregP said:


> In most carriers water was let into the fuel bilges for ballast because fuel floats on the water. It works except in violent seas when flying wouldn't be happening anyway. I realize bilges are planned out. What I was saying is simply that if they wanted to emplane liquid-cooled aircraft, they'd have to allow bilge space for coolant ... or space above the bilges, and I cannot see a way around that statement.


 And more a reason why another liquid wouldn't be welcomed aboard an aircraft carrier, at least a US one...


GregP said:


> You can't fly liquid cooled planes and expect the same coolant they emplane with to be used for the entire cruise. They lose some due to leaks and they also loose some due to maintenance. You MUST be able to replace it so the plane can fly.


Ditto above


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## FLYBOYJ (Oct 1, 2015)

A thread from a modeling forum about the Lockheed model 24.

Lockheed Model 24 (XFM-2) Navy Fighter


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## gjs238 (Oct 1, 2015)

How did the Brits manage the coolant issue on their carriers?


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## FLYBOYJ (Oct 1, 2015)

gjs238 said:


> How did the Brits manage the coolant issue on their carriers?



AFAIK they built stores for the coolant. Their decks were armored too!


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## BiffF15 (Oct 1, 2015)

FLYBOYJ said:


> AFAIK they built stores for the coolant. Their decks were armored too!



Brilliant!

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## GrauGeist (Oct 2, 2015)

gjs238 said:


> How did the Brits manage the coolant issue on their carriers?


Keep in mind that the U.S. Navy had 8 aircraft Carriers in service by 7 December 1941 and one more commissioned on 30 December, 1941.

The Langley, Lexington, Saratoga and Ranger were built before 1935, and were not large ships by latewar standards. By the mid-30's, the specs for the carriers reflected changes in naval aviation. However, all of these ships were built with the premise that the Navy would be using air-cooled engines of the day. Once the war got started, the carriers were still designed with intention of being outfitted with compliments of radial aircraft...so at no time, was provisions for "Prestone" storage made available. And in building a carrier (as with any warship), every square inch is accounted for in the way of function.

The Royal Navy, on the otherhand, had a history of using liquid-cooled engines for thier various Naval types, so their carrier's design would have included the necessary storage for the coolant.

Anyway, back to the original question, the navy did look into a navalized version of the P-39 the XFL-1. And here is another interesting note, regarding the Navy...they did not like nose-gear equipped aircraft, so the XFL-1 was built with conventional gear. It is an odd sight, seeing a P-39 tail-dragger... 
I might suggest reading Tommy Thomason's book: "Bell XFL-1 Airobonita" number 81 in the "Naval Fighters" series.

I might add that the Navy was certainly exploring twin-engined aircraft (in keeping with the recent P-38 discussion) and during the late 1930's, they had a Lockheed Junior converted for "sea trials". It was extensively trialed aboard the Lexington.


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## GregP (Oct 3, 2015)

This is plain silly. The Lexington had displacement of 36,578 tons and a full load displacement of 43,757 tons. If they had needed , say, 1500 gallons of coolant, it could have been EASILY done. The only quesiton is what goes in it and where is it placed.

I cannot see the argument about glycol being hazmat. They didn't know what hazmat WAS in those days. They knew what they needed and how to handle it. It wasn't a tough thing to accomplish. 1,500 gallons of coolant would NOT take up much room or displacement. The ONLY question would be where to put it and what gets bumped.

1,500 gallons is only about 200 cubic feet or 5.7 cubic meters. I can find 200 cubic feet on a 150 foot boat. It's 10 feet by 10 feet by 2 feet. If that is gonna' break the bank, sink the damed thing and be done with it. Make the wardroom 2 feet smaller. The ONLY reason they didn't do it is because the people who made the decisions loved air-cooled radials, not for any hazmat or storage reasons.

Get real and stop thinking like the EPA was around. It wasn't and NOBODY was worried about coolant storage. They were worried about what engine was best for Naval aviation and only that. If there wasn't a hose to deliver it, they could always use buckets. There was PLENTY of labor around. Sailor labor was "disposable" at that time.


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## FLYBOYJ (Oct 3, 2015)

GregP said:


> This is plain silly. The Lexington had displacement of 36,578 tons and a full load displacement of 43,757 tons. If they had needed , say, 1500 gallons of coolant, it could have been EASILY done. The only quesiton is what goes in it and where is it placed.
> 
> I cannot see the argument about glycol being hazmat. They didn't know what hazmat WAS in those days. They knew what they needed and how to handle it. It wasn't a tough thing to accomplish. 1,500 gallons of coolant would NOT take up much room or displacement. The ONLY question would be where to put it and what gets bumped.
> 
> ...


Greg, I was in the Navy - 1,500 gallons of extra anything would not be welcomed aboard ship - PERIOD. You're entitled to your opinions, I know Airdales who served aboard ships during WW2, mention glycol, they'll roll their eyes and say "that's stuff for the air force."


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## tomo pauk (Oct 3, 2015)

Just to put into a perspective how much the 1500 gals of anything is compared with Avgas stored in Lex Sara (from Wikipedia article about Lex):


> Avgas was stored in eight compartments of the torpedo protection system, and their capacity has been quoted as either 132,264 US gallons (500,670 l; 110,133 imp gal) or 163,000 US gallons (620,000 l; 136,000 imp gal).[11]



1500 gals of coolant means such big ship will carry roughly 1% less Avgas.


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## FLYBOYJ (Oct 3, 2015)

tomo pauk said:


> Just to put into a perspective how much the 1500 gals of anything is compared with Avgas stored in Lex Sara (from Wikipedia article about Lex):
> 
> 
> *1500 gals of coolant means such big ship will carry roughly 1% less Avgas*.



I could see a maintenance Chief blowing his top over that!


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## tomo pauk (Oct 3, 2015)

Maintenance chief will surely follow orders.


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## FLYBOYJ (Oct 3, 2015)

tomo pauk said:


> Maintenance chief will surely follow orders.


Er no - they make orders!!! In the US Navy Chiefs (E-7 and above) carry more weight then some officers in other branches of the military. I suggest you read about the US Navy and how it runs, some of my fellow sailors on here could attest to this.


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## tomo pauk (Oct 3, 2015)

I admit that I'm not that fluent in US military designations. 
Do we have any informations how this or that chief felt when in 1944 they were informed they will need to find the place for 1000, or 1500, or maybe 2000 gals of ADI fluid, that was chemically similar to the coolant? Including the chiefs on the tiny escort carriers operating FM-2s (500-1000 gals here?), and still small light carriers? 
Fifty Hellcats can consume ~800 gals of ADI in one sortie each.


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## FLYBOYJ (Oct 3, 2015)

tomo pauk said:


> I admit that I'm not that fluent in US military designations.
> Do we have any informations how this or that chief felt when in 1944 they were informed they will need to find the place for 1000, or 1500, or maybe 2000 gals of ADI fluid, that was chemically similar to the coolant? Including the chiefs on the tiny escort carriers operating FM-2s (500-1000 gals here?), and still small light carriers?
> Fifty Hellcats can consume ~800 gals of ADI in one sortie each.



We don't, but we do know the way a Chief felt when he discovered someone was jacking off in someone else's towel! 


_View: https://www.youtube.com/watch?v=1TlOD2anqOU_

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## GrauGeist (Oct 3, 2015)

Not sure how we came to the conclusion that it would be "only" 1,500 gallons of Prestone needed for a deployment.

If we average the coolant capacity to 22 gallons per aircraft and figure on roughly 45 fighters (could be more, could be less - this is just a generic figure), this gives us a working quantity of 990 gallons. So if we take the working quantity of 990 gallons and double it for the onboard storage reserve, that gives us a quantity of 1,980 gallons. Now I am pretty sure there would need to be just a little more on hand to replace any coolant lost due to overheating, combat damage and hard landing attrition. There will also be coolant lost during maintenance and engine swaps. This continued draw on the onboard storage will exist for the duration of the constant CAP and enemy encounters during the deployment. So now 1,980 gallons doesn't look like much, now does it?

So if there is not enough coolant on hand, you don't fly. This is why they made sure to have ample engine oil and hydraulic oil storage to be able to not only support each aircraft, but to be able to anticipate any emergency.


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## IdahoRenegade (Oct 8, 2015)

FLYBOYJ said:


> I could see a maintenance Chief blowing his top over that!



Liquid cooled engines typically are built to tighter clearances (less thermal expansion) and typically are more aerodynamic. As such, they should get significantly better fuel economy. Net impact on fuel utilization might well be positive with liquid cooled engines.


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## FLYBOYJ (Oct 8, 2015)

IdahoRenegade said:


> Liquid cooled engines typically are built to tighter clearances (less thermal expansion) and typically are more aerodynamic. As such, they should get significantly better fuel economy. Net impact on fuel utilization might well be positive with liquid cooled engines.



The US Navy in the late 1930s and into WW2 didn't think so.


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## GrauGeist (Oct 8, 2015)

IdahoRenegade said:


> Liquid cooled engines typically are built to tighter clearances (less thermal expansion) and typically are more aerodynamic. As such, they should get significantly better fuel economy. Net impact on fuel utilization might well be positive with liquid cooled engines.


Might want to check with the Imperial Japanese Army and Navy for their opinion...


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## IdahoRenegade (Oct 8, 2015)

GrauGeist said:


> Might want to check with the Imperial Japanese Army and Navy for their opinion...



I'm not sure we need to go that far. Didn't the Mustang have a significantly longer range than the Corsair, while carrying less fuel? 

IMO a far bigger issue than carrying glycol on a carrier is that aircraft with liquid cooled engines are much more vulnerable to battle damage (one hit anywhere in the cooling system and you're not going home) than radials. As such they aren't suited to an especially high-threat environment (single engine ones in particular). Carriers don't have the capacity of fixed airstrips to carry different aircraft for high-risk ground attack missions and others for straight air superiority/escort duties.


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## GregP (Oct 9, 2015)

1500 gallons wasn't a conclusion, it was an example number thrown out for nothing more than to show how little volume it took. My entire point is if they wanted to field liquid-cooled engines, it would not have been difficult, and I still can't see it being so, all posts to the contrary nothwithstanding.

The ONLY issue would be whether or not one of the dreaded liquid-cooled airplanes actually showed up in service. If it did, they'd handle it or be ordered to do so.

I also said the people making the choices were fliers when the Navy was firmly set along air-cooled guidelines and my belief is that's why they didn't elect to choose one ... becuase they weren't flying them when they were young-and-stupid pilots.

If the requiremnt isn't made, then no space for glycol will be found. If it HAD been made, space for it would absolutely have been found. Orders from above trump even the grizzliest Master Chief's desires, and if the planes were liquid-cooled, you'd have coolant or not fly much.

I doubt the air-boss/CAG would put up with that one.

I wasn't trying to change history ... I said if they needed to do it, they WOULD have. Sailors and Airdales don't get to "reject" aircraft that are embarked on a carrier by the Navy. They operate them. We all KNOW what they did, but it isn't the case that it couldn't have been another way.

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## FLYBOYJ (Oct 9, 2015)

GregP said:


> Orders from above trump even the grizzliest Master Chief's desires



They do but in the end many a line officer paid the price for pissing off their CMC. 



GregP said:


> Sailors and Airdales don't get to "reject" aircraft that are embarked on a carrier by the Navy.


you're right they don't but I'll state again that Navy CPOs have a HUGE decision on how things operate and they carry more weight then some officers in other branches of the US military.

BTW - I've seen Command Master Chiefs tell CAGs to stay away from maintenance shops and to come directly to them when they have "F*#king issues," always concluding the conversation with "Sir".


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## GregP (Oct 9, 2015)

I don;t doubt for a minute you saw that. I'd also say whoever wrote the Master Chief's reviews wasn't doing his or her job. Of course, if that Master Chief ran the tightest shop in the Navy and the CAG was a jerk, that's another story. There's always another story when those type of things crop up. If the CAG lost several pilots or ALMOST lost one due to maintenance-related problems that were known and ongoing, that's a whole diferent scenario.

I was working on Allisons when we shipped the engines for that P-38 to Westpac. In fact, Bill Clairs (spelling? I know the name but never saw it written anywhere) was a regular visitor to Joe Yancey's place. Looking forward to hearing about it flying.

I'd hazard a guess they'll likely have Steve Hinton do the test flights. All those guys are friends with one another. It will be good to have another fyable P-38 in the population. I think that would make 8, or maybe it's 7 and I'm counting the Westpac plane twice in my mind. A couple of years back we had 5 in the air all at once in formation at our airshow at Chino. We had another one on static from Yank's Air Museum, but they don't fly it. In fact, they didn't even start it.


_View: https://www.youtube.com/watch?v=awi6A9eLZ3k_

I still wonder what ever happened to the one they were working on down in Marana, Arizona at Evergreen when Dell Smith's boys both died in a car accident. The center section was done or largely done and they were starting on the outer wings. I never heard about it again after I saw it in the early 1990's, but for sure it wound up somewhere.

They also had a very nice Sikorsky Skycrane without rotor blades, complete with new engines! Turns out Skycrane rotor blades are EXPENSIVE.

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## Zipper730 (Nov 10, 2015)

The P-40 was strong and rugged, and probably wouldn't have gained too much weight to navalize it: It however didn't have enough visibility over it's nose (a problem that also plagued the F4U)

The P-39 was strong and rugged, but it wasn't really much different in speed than the P-40, and while the Navy didn't like nose-gears at the time: The primary problem with the P-39 was that it had almost no stall warning combined with overly sensitive controls.

The P-38 was huge with a wingspan of 52' -- bigger than the TBD Devastator: The proposed wing-fold would have kept the span at 31' which was probably bigger than the TBD (which was the first USN plane to use it).


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## GrauGeist (Nov 10, 2015)

Zipper730 said:


> The P-40 was strong and rugged, and probably wouldn't have gained too much weight to navalize it: It however didn't have enough visibility over it's nose (a problem that also plagued the F4U)


All USN aircraft at the time were "tail draggers" and as such, sucked for foreward vis over the cowling. Many USAAC/USAAF aircraft had the same problem (like the P-47)



Zipper730 said:


> The P-39 was strong and rugged, but it wasn't really much different in speed than the P-40, and while the Navy didn't like nose-gears at the time: The primary problem with the P-39 was that it had almost no stall warning combined with overly sensitive controls.


See my post (#47) regarding the navalized P-39...in order to satisfy the USN, Bell installed conventional gear on it.



Zipper730 said:


> The P-38 was huge with a wingspan of 52' -- bigger than the TBD Devastator: The proposed wing-fold would have kept the span at 31' which was probably bigger than the TBD (which was the first USN plane to use it).


Agreed...the P-38 had a very large profile due to it's twin fuselages.


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## Zipper730 (Nov 10, 2015)

GrauGeist said:


> All USN aircraft at the time were "tail draggers" and as such, sucked for foreward vis over the cowling.


Of course, but the P-40 was allegedly considered bad even by those standards



> See my post (#47) regarding the navalized P-39...in order to satisfy the USN, Bell installed conventional gear on it.


True, but IMHO, the desire to carry a conventional gear was really more of the fact that the USN weren't used to them. Ironically, the first aircraft landing aboard a warship had a nose-gear


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## GrauGeist (Nov 10, 2015)

The Curtiss Model D is a little bit of a stretch when comparing "modern" conventional to tricycle gear

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## Shortround6 (Jan 12, 2016)

The Main problems with trying to use Army type aircraft from carriers is the take-off and landing performance and the strength required. 
I am sure the Navy could have solved the coolant storage if they really wanted to, it was a strike against the liquid cooled planes but hardly the deciding factor had the Navy decided that they needed the performance of a liquid cooled powered plane. 

Take-off and landing requirements were changed during the course of the war. Pre-war requirements included a fair safety margin as Congress was _not_ buying aircraft in large numbers and operational losses were a serious consideration (last production batch of Devastator torpedo planes was to replace peace time losses while the TBF was designed and built.) Early carrier operations in 1942 were also limited (or constrained) by operational losses. The strikes against the Marshals and Gilberts saw more planes lost due to simple operations than due to enemy action/fire. Re-supply usually meant the task force had to return to base (or at least easy flying distance form base) late war supplies of escort (jeep) carriers meant Task Forces could stay on station (or deployed) and be supplied with aircraft from a few escort carriers acting as aircraft ferry's. 

Going from easiest to eliminate to hardest the P-39 can be written off right away. It is illuminating to look at however for the extremes. The P-39D-2 needed almost 3 times the runway length of an F4F. It needed about 60% more runway than the P-40 or P-38. The Navy Version, the Airabonita, was about 1000lbs lighter than an early P-39 (in part due to a much lighter armament?) and yet was fitted with a bigger wing (about 1 foot more span and 19 sq ft more area) in addition to going to tail dragger landing gear. Perhaps the increased wing incidence shortened the take-off run over the tri-cycle gear? 
USN operations were based on a fast take-off of the strike group. While a few planes might be catapulted off the deck in order to gain space the rest of the group was expected to simply fly off at short time intervals. Range of the strike group being limited to the amount fuel left in the fuel tanks of the first plane/s off the deck. Orbiting the carrier for 30 min or more while a substantial number of planes were catapulted impacts the operational radius of the strike group. 

The other 2 planes under consideration took about 50% more runway than the F4F. There is a reason the F4F had a wing about 13% bigger than a P-40 (and around 22% bigger than a P-39).

Low speed handling (especially lateral control) was as important as pure stalling speed. Suddenness of the stall was also a consideration, did the plane just "mush" or did it do a violent break? 

Navy planes also needed to be able to land at near take-off weights (at least early war) in case of mechanical problems. Granted they often had to wait for the flight deck to be cleared but fuel dumping provisions to lighten the plane may not have been fitted (I could be wrong about this). 

As far as strength goes, a lot of carrier landings were equal to a really bad landing on a land airfield. Vertical impact speeds on the landing gear (and supporting structure) could 1 1/2-2 times what a "normal" shore landing was. 
Some carrier landings went pretty smooth and some did not. Plenty of navy aircraft were written off after bad landings (reducing the strength of the air group until resupply), using planes that are going to hit the deck harder (higher speed) and might not have quite the strength is going to mean higher operational losses. 
Early F4Fs didn't have folding wings but once the F4F shows up reducing the total number of fighters (even if you can get a folding wing P-40) is not going to be looked on with favor. 

Throw in that the P-40 doesn't really have much performance margin over the F4F at 20,000ft and above until the "F" model with the Merlin shows up ( a trickle in the Spring of 1942) and I am not sure what you are gaining.

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## Peter Gunn (Jan 14, 2016)

All very interesting thoughts which gives me much food for thought. I myself without any source documents to back it up, _assumed_ the Navy was happier with air cooled engines because of not wanting to find/design in storage space for coolant. Also what Greg said about extra space for replacement parts for said cooling system (radiators,hoses, caps etc.). Now I'm not so sure, thanks for giving me a mission to start digging into my old Navy stuff I haven't touched in too many years.

On the differences between say the F4F and the P-40 it brought to mind research I did for a guy years ago for some publication he was doing on naval cannons. The Army versions of 14 and 16 inch guns for coastal defense were substantially heavier and had further range than their naval counterparts because weight was not a consideration. They might have even fired heavier shells although I'd have to look that all up again.

I find things like this fascinating where you have two planes, or guns, tasked with the same job but end up with a different paradigm because of who is deploying them and where.


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## Shortround6 (Jan 14, 2016)

The Navy had had some bad experiences with liquid cooled engines (Liberty and Packard V-12s) in the 1920s. These engines were water cooled and not glycol or a glycol mix. However a number of forced landings due to coolant system leaks (and lost planes, Navy planes forced to land in water being far less recoverable than Army planes landing in farmers fields/pastures) had soured the Navy on liquid cooled engines in general. Planes/engines in the late 30s/ early 40s were much more reliable but the Ensigns/Lieutenants of the 1920s were now Captains/Admirals and getting past their own experiences/memories was going to take more than a few percentage points in performance. 
The weight issue was also there. The Packards also fell from favor when P&W and Wright could offer similar power for lower installed weight. Around 1930 with high drag biplanes, lousy radiator/uncowled radials, fixed landing gear the liquid cooled engines couldn't show any real reduction in drag/change in performance to justify their weight ( take off distance or payload restrictions) in the restricted weight Navy planes compared to Army Planes with longer runways available. A lot easier to sometimes bulldoze a line of trees than add 100 ft to a carrier hull.


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## ChrisMcD (Jan 14, 2016)

Shortround6 said:


> The Navy had had some bad experiences with liquid cooled engines (Liberty and Packard V-12s) in the 1920s. These engines were water cooled and not glycol or a glycol mix. However a number of forced landings due to coolant system leaks (and lost planes, Navy planes forced to land in water being far less recoverable than Army planes landing in farmers fields/pastures) had soured the Navy on liquid cooled engines in general. Planes/engines in the late 30s/ early 40s were much more reliable but the Ensigns/Lieutenants of the 1920s were now Captains/Admirals and getting past their own experiences/memories was going to take more than a few percentage points in performance.
> The weight issue was also there. The Packards also fell from favor when P&W and Wright could offer similar power for lower installed weight. Around 1930 with high drag biplanes, lousy radiator/uncowled radials, fixed landing gear the liquid cooled engines couldn't show any real reduction in drag/change in performance to justify their weight ( take off distance or payload restrictions) in the restricted weight Navy planes compared to Army Planes with longer runways available. A lot easier to sometimes bulldoze a line of trees than add 100 ft to a carrier hull.



I agree completely - hence the old quote "The USN will switch to liquid cooled engines about the time that it switches to air cooled submarines."

Mind you, Winkle Brown did get an Airacobra onto an carrier

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## GrauGeist (Jan 14, 2016)

Shortround6 said:


> As far as strength goes, a lot of carrier landings were equal to a really bad landing on a land airfield. Vertical impact speeds on the landing gear (and supporting structure) could 1 1/2-2 times what a "normal" shore landing was.
> Some carrier landings went pretty smooth and some did not. Plenty of navy aircraft were written off after bad landings (reducing the strength of the air group until resupply), using planes that are going to hit the deck harder (higher speed) and might not have quite the strength is going to mean higher operational losses.


Might have to disagree somewhat about this...

Typically, a landbased (army, etc.) aircraft has the luxury of a static field with ample room for approach, flare and touch-down/rollout - the landings typically being modest unless you had a short-hour rookie or a shot-up crate.

In the case of the carrier landings, they came in and "plopped down" as soon as possible, the arrestor cable amplifying this effect, the result being a bone-jarring experience. There were even a few naval types that had to have the oleos modified because the landing was so harsh, that the aircraft would jump up, loft and either collide with other aircraft or go overboard.

We had a Sherrif (passed away several years ago and is still missed) who owned a 172 and flew it for ages. You could tell he was old-school Navy, as he'd sit at the end of the local field, run that poor Lycoming up until it was screaming for mercy and then he'd start his roll. He'd always get up before mid-field and away he'd go.

The return was always a sight, though. He'd make his approach close and at roughly 45 degrees and drop that poor 172 down like a sack of concrete. This is a prime example of now only how rugged a Cessna is, but how old Navy pilots never change! 

By the way, he was a WWII vet and got his baptism of fire at Midway.

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## Shortround6 (Jan 14, 2016)

We might not be in much disagreement. I may not have worded the post quite right. Not being a Naval aviator I went by watching a few on line videos and the sample might have included a few better than average landings. Not having a "typical" landing video after a very short search (either smooth ones or near if not outright crashes) I went for mild wording. There is little doubt on average the carrier planes landed harder than land based planes ( either that or the navy really screwed up on the specs  But you can always find pictures/video to show the exceptions. 

Like landing the P-39 on a carrier. Just because something is not 100% impossible doesn't mean it is really a good idea. Full details of exactly what Capt Brown was doing with the P-39 may be a bit lacking but some details are here. 

https://en.wikipedia.org/wiki/AH574 

A number of approaches flown in a test program designed to provide information for future jet aircraft without landing gear to land on flexible (rubber?) decks and one actual landing with the plane in a "test" configuration (ammo? guns? armor? fuel state?) by a pilot with quite possibly the highest number of carrier landings in the world at the time is hardly proof that "average" pilots could land in poor weather flying planes in combat configuration.

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## GregP (Jan 14, 2016)

I cracked up at "advanced state of decay ...".

One man's garbage is another man's treasure.


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## parsifal (Jan 15, 2016)

RN Carriers trained hard for fire hazard controls, and also built into their carrier designs certain features that I don't think were worked into US designs until later on. 

Hangars were closed, meaning far greater integrity against the spread of fire. all flammable storage had the ability to be flooded, or smothered in CO2 or cooled with seawater to limit the spread of fire. Hangars usually had internal subdivision in which fire proof steel curtains would drop in an emergency, and of course all hangar areas were protected by sprinkler systems. There was a price for the much higher levels of protection worked into RN carriers, they carried a fraction of the air groups in US carriers. Even as late as the '80s I can vouch that the RN safety systems devised in WWII were still ahead of their USN post war carriers . Storage of coolant was not a problem in the RN at all. It just added weight and took away from the carriers ability to carry a/c. slight problem really.....

There are misconceptions in the radial versus inline debate on both sides. For a while in the RN at the end of the 1930s it was considered that in lines had an inherent performance advantage. not much basis for it, but an assumption that existed. Later it was realized that deck views from an inline was generally less good eg the Seafire. 

Truth is, both radials and inlines could go to sea AND give good service. each had inherent idiosyncrasies, but none of these quirks were in any way major issues.

But I think the P-38 might have been an issue. Having built it as a model, its a big aircraft, and this would have reduced the complement that could be carried. propr rotation might be an issue, and controllability I would be interested to hear about. The p-38 was a handful ive read, and that suggests it might be difficult in carrier operations. Carrier a/c pre-1945 had to have a level of docility in both their takeoff and landing characteristics or loss rates could go off the charts. again I think of the seafire. it had some handling issues that made it hard to manage. by comparison, the sea hurricane, also a quick lash up conversion, was a pretty good deck handler. ive got this horrible feeling about the Lightning. I suspect it would have been a real beast in terms of handling and attrition....but open to correction....


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## GregP (Jan 15, 2016)

Handling is fine when it isn't one of the non-turbo-both-engines-turn-the-same-way units (the model 322). If you read this report (
_View: https://www.youtube.com/watch?v=ar-poc38C84_

In fact, they landed and took off U-2s from a carrier in CIA tests!


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## GregP (Jan 15, 2016)

Here's a clip of the U-2 carrier test:


_View: https://www.youtube.com/watch?v=Weuq--G8u_0_


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## GrauGeist (Jan 15, 2016)

Greg...didn't you know that the P-38s had their own carriers?


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## Shortround6 (Jan 15, 2016)

And could take-off backwards, over the stern 

Folding the wings isn't going to gain much, most logical fold point being the break between the alerons and the flaps. Folding inboard of the outer edge of the prop circle may be possible but adds complication to flap system and doesn't gain much for storage/handling without a lot of shenanigans ( turning prop blades just so, etc) and very careful placement of aircraft.


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## tomo pauk (Jan 15, 2016)

parsifal said:


> ...
> But I think the P-38 might have been an issue. Having built it as a model, its a big aircraft, and this would have reduced the complement that could be carried. propr rotation might be an issue, and controllability I would be interested to hear about. The p-38 was a handful ive read, and that suggests it might be difficult in carrier operations. Carrier a/c pre-1945 had to have a level of docility in both their takeoff and landing characteristics or loss rates could go off the charts. again I think of the seafire. it had some handling issues that made it hard to manage. by comparison, the sea hurricane, also a quick lash up conversion, was a pretty good deck handler. ive got this horrible feeling about the Lightning. I suspect it would have been a real beast in terms of handling and attrition....but open to correction....



The P-*39* was sometimes described as a handful, the P-*38* was docile. Much to the credit goes to the Fowler flaps that increased both take off and landing qualities, as well as maneuverability. It was also one of better 2-engined aircraft for flying with just one engine.

An excerpt from the test Greg kindy provided the link:


> B. Take-off
> 
> The take-off characteristics of the P-38J are normal for a tricycle gear airplane except for the absence of any noticable torque effect due to the opposite rotating propellers. The airplane takes off after a short ground run and has a steep initial angle of climb. Vision during take-off and climb is good.


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## parsifal (Jan 15, 2016)

Well, those landings are tight, but i would put this clip up against it and claim the landing was even tighter. HMAS Melbourne, 12000 ton Light Carrier . From Flight Deck Ops, the wing would pass over your head as the bird was landing. Tracker pilots getting their carrier qualifications. 

After 1975, only RAN pilots were crazy enough to land on the old girl. Yanks thought our guys were nuts. In hindsight, they were probably right


_View: https://www.youtube.com/watch?v=HoEElPX8hfQ_

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## FLYBOYJ (Jan 15, 2016)

GregP said:


> But I don't think they ever LANDED a B-25 on a WWII carrier.

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## pinsog (Jan 18, 2016)

How much weight did the silly car door add to the P39 over a standard canopy? 
What would an extra 6 inches per wing do for low speed handling on a P39? What would effect be on performance and maneuverability? 
What would an extra 1 foot per wing do for low speed handling on P39? Would would be the effect on performance and maneuverability?


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## GrauGeist (Jan 18, 2016)

pinsog said:


> How much weight did the silly car door add to the P39 over a standard canopy?


it would probably take a good deal redesign for the fuselage to accept a sliding canopy as the engine cowling and intake are located directly behind the cockpit...


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## bobbysocks (Jan 18, 2016)

GrauGeist said:


> run that poor Lycoming up until it was screaming for mercy



that is the first time I have heard that expression used in like forever....lol

a good pilot can put anything down on a carrier if they wanted.....


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## Shortround6 (Jan 18, 2016)

GrauGeist said:


> it would probably take a good deal redesign for the fuselage to accept a sliding canopy as the engine cowling and intake are located directly behind the cockpit...



Simple. Rear canopy stays in place. Wind screen/front canopy slides forward 

Bailing out at speed might be a slight problem 

A sliding bubble was done on the P-63E but I have no idea how much trouble it was or if the shorter length canopy hurt performance (higher drag?)


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## GrauGeist (Jan 18, 2016)

Shortround6 said:


> Simple. Rear canopy stays in place. Wind screen/front canopy slides forward
> 
> Bailing out at speed might be a slight problem
> 
> A sliding bubble was done on the P-63E but I have no idea how much trouble it was or if the shorter length canopy hurt performance (higher drag?)


Sliding foreward would also present a problem, because the weapon bay access would have to be modified, too.

Bell could have made the canopy based on Messerschmitt's "side-swing" design, perhaps...

In any case, the layout of the P-39 made any other type of canopy very difficult to consider.


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## wuzak (Jan 18, 2016)

GrauGeist said:


> Sliding foreward would also present a problem, because the weapon bay access would have to be modified, too.



It could have slid rearwards, Spitfire style.

Or, for a proper bubble canopy, rework the air intake.


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## GrauGeist (Jan 18, 2016)

wuzak said:


> It could have slid rearwards, Spitfire style.
> 
> Or, for a proper bubble canopy, rework the air intake.


But like I mentioned before, the rear portion of the cockpit/canopy is part of the engine cowling.

I am willing to bet that Bell took all the current canopy types into consideration when they designed it and this was the most economical and effective design.

I'm sure that a bubble canopy may have been easier to install on a hurricane than a P-39.


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## GregP (Jan 18, 2016)

Regarding POST 82, that's astounding, Was that done more than once, or was that a trial only?

I'm trying to figure out where they attached the arrester hook, structurally. Not that it would be prohibitive almost anywhere, but just from curiosity. I can't imagine it was more than a test

I see it happened in 1944 aboard the Shagri-La. Had not heard that. I pretty sure the Doolittle raiders were all put aboard the carrier with a crane at Alameda.


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## GrauGeist (Jan 18, 2016)

GregP said:


> Regarding POST 82, that's astounding, Was that done more than once, or was that a trial only?
> 
> I'm trying to figure out where they attached the arrester hook, structurally. Not that it would be prohibitive almost anywhere, but just from curiosity. I can't imagine it was more than a test
> 
> I see it happened in 1944 aboard the Shagri-La. Had not heard that. I pretty sure the Doolittle raiders were all put aboard the carrier with a crane at Alameda.


The Navy was using a Marine Corps PBJ-1H that had the arrestor hook anchored to the tail-skid mount.

They trialed it several times, under varying conditions in both T/O and landing. The Navy ultimated decided not to pursue it further, even though the trials were successful.

And yes, the Doolittle raiders were craned aboardship.

Here's the USMC PBJ-1H (43-4700 - BuNo. 35277) seen aboard the Shangri-La during trials:

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## GregP (Jan 18, 2016)

We usually fly our B-25J with the side gun mounts as seen here, but also with the clear bomber nose (not the solid gun nose). The side gun mounts take off about 12 knots or so, so we usually remove them for photo missions.

When I say "we," I mean Planes of Fame, not specifically Greg.


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## Peter Gunn (Jan 19, 2016)

pinsog said:


> How much weight did the silly car door add to the P39 over a standard canopy?
> What would an extra 6 inches per wing do for low speed handling on a P39? What would effect be on performance and maneuverability?
> What would an extra 1 foot per wing do for low speed handling on P39? Would would be the effect on performance and maneuverability?



On the canopy, I always thought Bell did quite a remarkable job with it considering the engine intake etc. Also, did the door add any extra weight over what would have been solid fuselage? If so, how much? Valid questions from me, not being combative.

Also I thought that Bell came up with a pretty good "almost a bubble" canopy solution with that, certainly closer than a P-40, 47, 51, Corsair, Spitfire, Hurricane etc. had in their first iterations.


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## tomo pauk (Jan 19, 2016)

The excess weight of the P-39 vs. Euro-Asian fighters of the era comes out from excess weight of guns & ammo, not from the 'silly car dors'. That and cockpit canopy were the last of the worries.
Agains most of European designs powered by V-12 engines, it aso carried a bit more fuel, that again adds weight, so do the up to 3 radios.


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## pinsog (Jan 19, 2016)

tomo pauk said:


> The excess weight of the P-39 vs. Euro-Asian fighters of the era comes out from excess weight of guns & ammo, not from the 'silly car dors'. That and cockpit canopy were the last of the worries.
> Agains most of European designs powered by V-12 engines, it aso carried a bit more fuel, that again adds weight, so do the up to 3 radios.



Agreed. I know it was over armed for its horsepower. I thought they might save some weight by doing a standard canopy (I think I saw on this site somewhere that the car door added several hundred pounds because of the way it had to be built. But that may not be right) and of course making it easier to bail out of

I know the P39 had low speed handling issues, would 6 inches or so added to each wing solve the low speed handling?

I like the idea of a P39 for the US Navy. Slightly longer wings that fold for better low speed handling, ditch the wing guns and put wing tanks in there place for better range, keep 2 synchronized 50's and the 37mm, fix the ejection chute on the 37mm so it is reliable, ditch part of the armor and some of the radios. The P39 is very fast, P39C climbed exceptionally well, had great performance below 15,000 feet, and if the 37mm was reliable it would be awesome at dropping Kate torpedo planes before they got to the carrier.


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## tomo pauk (Jan 19, 2016)

Fuselage of the P-39 weighted ~620 lbs, containing also the engine. Fuselage of the P-40B weighted 420 lbs, add the weight of the engine section - 300 lbs - for total of 720 lbs. So maybe we could see some saving in not having car dor entry, I'm not too sure the weight savings is in the range of 'several hundred pounds'


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## Shortround6 (Jan 19, 2016)

One analysis of the P-39 claims 50lbs for the drive shaft and 50lbs worth of fuselage "stiffening" to keep the Propeller in line. No mention is made of the canopy or doors. You do need to keep the fuselage flex to a minimum if the prop is 10 feet away from the engine. Perhaps if the doors were not there, that section of the fuselage could have been made lighter?


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## GrauGeist (Jan 19, 2016)

pinsog said:


> ...I thought they might save some weight by doing a standard canopy (I think I saw on this site somewhere that *the car door added several hundred pounds* because of the way it had to be built. But that may not be right) and of course making it easier to bail out of...


I would love to see that source, as the door of the P-39 was constructed mostly of aluminum.

For comparison, the driver's door on my 1966 Mustang weighs under 100 pounds and that's with window regulator bellcrank, glass and track plus latch and release/handle assembly.


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## pinsog (Jan 19, 2016)

I have no idea where I read that the P39 gained a lot of weight do to the car door cockpit, I think I read it on here, but I read so much in so many places I can't give a source and it may be completely wrong. I make no claims either way, that is why I asked for verification. I thought they said it had to do with the extra structure required elsewhere to stiffen it back up because of the big gaps in both sides of the fuselage (like cutting the roof off a normal ca to make a convertible)


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## GrauGeist (Jan 19, 2016)

If you go back to my post #87 and look at the P-39's diagram, you'll see the subframe assembly that the cockpit attached to.
The cockpit subassembly would have added additional weight to the total airframe weight, but it also tied in with the airframe, adding additional strength.

As it is, removing the car doors and installing a conventional canopy wouldn't help the weight issue much, as the cockpit subassembly would still exist as a component.

Again, referring to the diagram, you can see how the cockpit is designed to be removed in it's entirety in order to perform extended maintenance


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## pinsog (Jan 19, 2016)

GrauGeist said:


> If you go back to my post #87 and look at the P-39's diagram, you'll see the subframe assembly that the cockpit attached to.
> The cockpit subassembly would have added additional weight to the total airframe weight, but it also tied in with the airframe, adding additional strength.
> 
> As it is, removing the car doors and installing a conventional canopy wouldn't help the weight issue much, as the cockpit subassembly would still exist as a component.
> ...



Ok. Thank you.


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## stona (Jan 19, 2016)

To get an idea of suitability for carrier operations it would be nice to know some data like take off speeds and runs at various operational weights. At the other end things like landing speed, how much margin above stalling speed did this give? How about the maximum rate of descent (ft/sec) that the undercarriage was designed for. The undercarriages of carrier aircraft were typically designed to deal with a much greater rate of descent than aircraft operated from fields or runways. They were also designed with different oleos etc to prevent the aircraft bouncing down the deck. They were invariably heavier. The angle of the undercarriage is relevant, many land based tail draggers were not designed to make the three point landings generally required for deck landing. In the case of the Seafire the three point attitude exerted a bending force on the main undercarriage which often tore it out of the wing! Others might suffer from similar problems with their landing gear geometry. There may also be aerodynamic problems. These might be irrelevant or even useful when landing on an airfield but potentially lethal when alighting on a carrier.
To navalise an aircraft designed for land based operations to make an acceptable carrier aircraft is often a LOT more difficult than it first appears. What is acceptable? The FAA eventually got the ratio of sorties to deck landing crashes, writing off the aircraft (not all accidents), down to 1:50 for the Seafire III. It took time and improvements in every aspect of operation and training to accomplish this much. It had been much higher on earlier operations. At Salerno the ratio for aircraft written off to all causes except engine failure per sortie was almost 1:10. 
1:50 might seem been okay in 1944, but what number is good enough for your navalised P-38/39/40?

Cheers

Steve


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## pinsog (Jan 19, 2016)

stona said:


> To get an idea of suitability for carrier operations it would be nice to know some data like take off speeds and runs at various operational weights. At the other end things like landing speed, how much margin above stalling speed did this give? How about the maximum rate of descent (ft/sec) that the undercarriage was designed for. The undercarriages of carrier aircraft were typically designed to deal with a much greater rate of descent than aircraft operated from fields or runways. They were also designed with different oleos etc to prevent the aircraft bouncing down the deck. They were invariably heavier. The angle of the undercarriage is relevant, many land based tail draggers were not designed to make the three point landings generally required for deck landing. In the case of the Seafire the three point attitude exerted a bending force on the main undercarriage which often tore it out of the wing! Others might suffer from similar problems with their landing gear geometry. There may also be aerodynamic problems. These might be irrelevant or even useful when landing on an airfield but potentially lethal when alighting on a carrier.
> To navalise an aircraft designed for land based operations to make an acceptable carrier aircraft is often a LOT more difficult than it first appears. What is acceptable? The FAA eventually got the ratio of sorties to deck landing crashes, writing off the aircraft (not all accidents), down to 1:50 for the Seafire III. It took time and improvements in every aspect of operation and training to accomplish this much. It had been much higher on earlier operations. At Salerno the ratio for aircraft written off to all causes except engine failure per sortie was almost 1:10.
> 1:50 might seem been okay in 1944, but what number is good enough for your navalised P-38/39/40?
> 
> ...



All good points Steve. I certainly think the low speed handling would need to be better and a lower stall speed would be nice. I wonder what an extra foot of wingspan would do for both? Anyway, the early war US Carriers could certainly use a plane that was faster and better climbing than the F4F4 Wildcat. Wonder if P39's with their extra performance could have climbed fast enough to break up the dive bomber attack on the Yorktown at Midway? They would certainly be better at shooting down Kate torpedo bombers at wave top height, between their high speed at sea level and a 37mm cannon (provided the ejector chute was modified making the 37mm reliable)


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