P-51K War Service

[DaveBB]

Earl is probably talking about the modifications from the B or early block D models to later block D models. 

The P-51H was the production version of testing from the lightweight Mustang program.  It was derated in G's, had less horsepower at mil-power, and was considered more fragile.

[Guppy35]

Lets make this simple

One of these is a P51K and one is a P51D.  Tell me which is which and how you can tell.

[Delirium]

The top one looks like it is uncuffed, but it is near impossible without reading the placard.

[pipz]

I'll take a shot at the top one being a D. The canopy.

[MiloMorai]

(4)4-11751 P-51K-1-NT

(4)4-74607 P-51D-30-NA

[Guppy35]

the only way to really tell is the serial number.  See a 411 or 412 at the beginning and odds are better it's a K.  Point being the D and K are essentially the same bird.  Interestingly in the two photos the top bird has the Inglewood style canopy and the lower D model the Dallas style canopy, probably retrofitted later.

[Chalenge]

The P-51H was the production version of testing from the lightweight Mustang program.  It was derated in G's, had less horsepower at mil-power, and was considered more fragile.

Incorrect about the G's. It was lighter, so it didn't need as much power at mil-power. It was not more fragile.

Not that it matters. You won't ever see one in AH.

[drgondog]

The "K" was re-designed as a ground attack aircraft and was never intended as a air to air combat aircraft as the "D" was! It had heavier oleo struts on the landing gear system, because of the extra ords it was capable of carrying! If memory serves me correctly, the "fillet" at the point where the wing joins the fuselage was also slightly larger and the wing had a different "washout" to the tips for better stall handling!
The vibration issue was resolved when they start "balancing" the blades of the prop and made sure they were within certain limits! The prop blades were also "magnufluxed" because some had some small cracks located and found during "IRAN" inspections. (Inspection and Repair as necessary) Some of the last ones built had a slightly different canopy to accommodate a jump seat in the rear and or instructor controls! Most of the Cavalier modified ponies had the enlarged canopy as most all where two place aircraft.

The sole difference between the P-51K airframe was the Prop/spinner and otherwise was exactly the same as the P-51D NA, P-51D NT. There were two major canopy versions as described above.

 The washout 'difference, in the K was exactly the same as both P-51D versions but all were different from the P-51A/B/C wing from Root Chord to ~ WS 61.5. The washout from 61.5 to the tip chord is exactly the same for P-51, P-51A/B/C and A-36 as well as the P-51D/K.

The bomb racks were rated at 1000 pounds as were all P-51D/K and retrofitted B/C racks - the only difference was less drag for the D/K than the B/C. The weight of the 1000 pound bomb was about the same as the 165 gallon drop tank...

The only difference in oleo strut design that I am aware of was the LW XP-51F/G/J and P-51H which was designed to a less robust strut/tire capability in the new wing.

The TF-51D-25-NT built at Dallas in 1945 had the same modified canopy as the later TF-51D-25-NT built in 1951 at Temco in Texas.

[drgondog]

The P-51H was designed at 7.5G Limit Load at 8,600 pounds. The P-51, A/B/C/D/K and A-36 were designed to 8G at 8000 pounds.  That being said, at P-51H Takeoff Gross Weight for same load out as P-51D was STRONGER than the P-51D.

Fully loaded with 255 gallons of internal fuel, guns and 1820 rds pf ammo, the P-51H GWTO = 9495

at 7.5G for 8600 pounds--> 64500 pounds, then actual permissible G load at 9495 = 64500/9495 = 6.8 G Limit for 9495 pounds.

The same load out for 51D with 269 gallons, guns and ammo, the P-51D/K GWTO = 10,208

At 8G for 8000 pounds ---> 64000 pounds, then actual permissible G load at 10,208 = 64000/10208 = 6.27 Limit for the comparable P-51D/K

Not to mention that the spar/bulkhead and carry through structure for the P-51H empennage was re-designed to make it stronger for asymmetric loading such as slow rolls.

[drgondog]

The 1650-9 was a beefed up 1650-3 with better internal design for crankshaft lubrication and new carb/boost control that was buggy for first flight tests but the Military power was the same as the -3 which was less than the 1650-7 until FTH was reached.

After the war 150 Octane was discontinued and the advantages of 80" boost (dry) and 90" (wet) were reduced to 67" War Emergency and partially emasculated the full potential of the P-51H.

It was still a cleaner airframe however with CDo at 9.0x10^^6 RN of .0153 compared to .0161 for the B/C/D/K (all without racks)

[Guppy35]

If I didn't know better I'd think drgondog was the son of a combat 51 pilot....err...wait!   

[Seadog36]

Okay, sounds like the K did see some service in WWII withe the RAF and in the Pacific. The question wasn't what us the difference between the D and K. Anyone have specific war service information?

[drgondog]

Okay, sounds like the K did see some service in WWII withe the RAF and in the Pacific. The question wasn't what us the difference between the D and K. Anyone have specific war service information?

Yes - there were a lot of P-51K-1's through -10-NT in 8th AF.

For example 44-11362 P-51K-1-NT; 44-11630 and 44-11667 and 44-11759 P-51K-5-NT's and 44-12122 P-51K-10-NT flew with 355th FG in 8th AF/ETO.

[Guppy35]

Okay, sounds like the K did see some service in WWII withe the RAF and in the Pacific. The question wasn't what us the difference between the D and K. Anyone have specific war service information?

That's an 8th AF 364th FG P51K I posted up thread.    I mentioned 357th FG Ace Kit Carsons P51K upthread as well.  The Group CO of 364th FG flew a K.  The list goes on and on

[earl1937]

The P-51H was designed at 7.5G Limit Load at 8,600 pounds. The P-51, A/B/C/D/K and A-36 were designed to 8G at 8000 pounds.  That being said, at P-51H Takeoff Gross Weight for same load out as P-51D was STRONGER than the P-51D.

Fully loaded with 255 gallons of internal fuel, guns and 1820 rds pf ammo, the P-51H GWTO = 9495

at 7.5G for 8600 pounds--> 64500 pounds, then actual permissible G load at 9495 = 64500/9495 = 6.8 G Limit for 9495 pounds.

The same load out for 51D with 269 gallons, guns and ammo, the P-51D/K GWTO = 10,208

At 8G for 8000 pounds ---> 64000 pounds, then actual permissible G load at 10,208 = 64000/10208 = 6.27 Limit for the comparable P-51D/K

Not to mention that the spar/bulkhead and carry through structure for the P-51H empennage was re-designed to make it stronger for asymmetric loading such as slow rolls.

Would have been nice to know all these things, back in the day, but I did good just to remember the starting sequence!