Navalized P-38/39/40: pros cons

[GregP]

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.

 

[FLYBOYJ]

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.

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".

 

[GregP]

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.

 

[Zipper730]

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).

 

[GrauGeist]

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)

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.

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.

 

[Zipper730]

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

 

[GrauGeist]

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

 

[Shortround6]

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.

 

[Peter Gunn]

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.

 

[Shortround6]

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.

 

[ChrisMcD]

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

 

[GrauGeist]

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.

 

[Shortround6]

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.

 

[GregP]

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

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

 

[parsifal]

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....

 

[GregP]

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!

 

[GregP]

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


View: https://www.youtube.com/watch?v=Weuq--G8u_0

 

[GrauGeist]

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

 

[Shortround6]

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.

 

[tomo pauk]

...
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.