What if the F-82 was based off the XP-51F/G instead of the P-51H?

[PStickney]

Actually, the NA-133 Proposal (not accepted) had only the tail hook and some wing changes - strengthened spar/main gear and slight crank to the inboard leading edge to accomadate wheel well changes for larger wheel. I have no idea why NAA even wasted time on the proposal - the USN would not (Could Not) buy a in-line engine for carrier ops - every gallon of coolant was a gallon less of AvGas.

Ethylene Glycol (Prestone) is flammable - That Navy really doesn't like having any more flammable liquids on a ship than they absolutely have to have.
Add in the need to be messing around with radiators, ducts hoses, and large quantities of liquid working on a hangar deck...
Let's just say that after the 1920s, the U.S. Navy was as likely to use a liquid cooled engine in an airplane as an air cooled engine in a submarine.

 

[PStickney]

Wonder of the Royal Navy would've been interested to have a longer ranged plane than a Seafire?

I'm really looking forward to the new book once it's completed, even if it doesn't have much on the F-82.

They had them. F6F Hellcats and F4U Corsairs. The Seafire, while once in the air, was a very good Point Defense Interceptor, was horrendous around the boat. Even in combat, most Seafire writeoffs were from landing accidents. Thing is, they had to give the Hellcats and Corsairs back at the end of the War (Lend-Lease), and could only build Sea Furies at a moderate rate, so there were Seafires serving postwar, but pretty much by default.

 

[tomo pauk]

Ethylene Glycol (Prestone) is flammable - That Navy really doesn't like having any more flammable liquids on a ship than they absolutely have to have.

A fighter with 2000 HP radial engine will require much more of inflammable liquid per air mile covered than a 1500 HP V12, yet USN had no problems in ordering the fighters powered by 2000 HP engines and stocking the inflammable liquid for these.
Wrt. future USN fighters of the day, problem with US V12s in very late 1930s was that they were not offering anything close to what R-2800 was offering. That was the killer.

Add in the need to be messing around with radiators, ducts hoses, and large quantities of liquid working on a hangar deck...

Radiators were pretty much fixed item, no need to mess with them that much? Large quantities of liquid - again, the big radials were the ones requiring it, the V12s less so. Even a R-1820- or R-1820-powered fighter will offer worse fuel mileage than a V-1710, but then again V-1710 was not available in the 1930s.
Problem with leakage might be present, since 100% pure Prestone was harsh on materials used in early 1930s.

 

[PStickney]

Fixed it.

Coolant was not really a consumable. The plane was expected to return with the same amount of coolant it left with (or nearly) unlike oil and fuel.

How much coolant did the Mustangs you flew use per flight?

The Navy was certainly using some fuel hog aircraft with those R-2800 engines.

Until you had to work on the cooling system, at which point you're draining the cooling system and probably disposing of it.
A cooling system hit on a carrier airplane was a certain loss - and, quite likely a lost crew. When there's nothing but water below for the whole mission...

And, pulling out the manuals, when dialed back for range cruise, both the P-51D and F4U-4 were drinking fuel at 40-45 U.S. gallons / hr. (Surprised me, too)

 

[ThomasP]

Apples to Apples

P-51C/D w/2x75 USgal DT = 330 USgal, - 33 USgal allowance for WUTO & climb to 20,000 ft = 297 USgal for range
best range cruise = 1700 miles at ~250 mph TAS = 44 USgal/hr
max weak mixture cruise range = 1050 miles at ~300 mph TAS = 85 USgal/hr

F4U-1/1A/1B w/1x170 USgal DT = 407 USgal, -75 USgal allowance for WUTO & climb to 20,000 ft = 332 USgal for range
best range cruise = 1290 miles at ~250 mph TAS = 64 USgal/hr
max weak mixture cruise range = 750 miles at ~300 mph TAS = 138 USgal/hr


Both aircraft have a V for best range of 180-185 mph IAS which is ~250 mph TAS at 20,000 ft.

Both aircraft can use significantly less fuel at lower altitudes and lower speeds.


P-51C/D as above but flight altitude is only 1,500 ft
best range cruise = ~1800 miles at ~182 mph TAS = 32 USgal/hr (10 USgal allowance for WUTO & climb to 1,500 ft)

F4U-1/1A/1B as above but flight altitude is only 1,500 ft
best range cruise = ~1500 miles at ~182 mph TAS = 42 USgal/hr (16 USgal for WUTO) & climb to 1,500 ft)

So at V for best range, at high altitudes the P-51 uses about 20 USgal/hr less (~30% less) fuel than the F4U-1, and at low altitudes about 10 USgal/hr less (~24% less), for the same ~speeds with the P-51 achieving significantly longer ranges.


If I did my math right.

NOTE that these numbers match up by both the US PFOI manuals and the UK Pilot's Notes to within a couple of %.