P-51K War Service

[Seadog36]

Anyone know if the 51K saw service in WWII. I was under the impression Korea was it's first combat arena.

[Chalenge]

P-51D = P-51K, although the K has a different prop. That's it.

[pipz]

Didnt they also have slightly different canopies as well?

[Ack-Ack]

P-51D = P-51K, although the K has a different prop. That's it.

And the K was built in Dallas while the D was built in Inglewood.  Also, the prop on the K was a POS compared to the D's prop.

[MiloMorai]

 Serials of the P-51K:


44-11353/11552      North American P-51K-1-NT Mustang
            c/n 111-29486/29685.  200 aircraft
44-11553/11952      North American P-51K-5-NT Mustang
            c/n 111-29686/30085.  400 aircraft
44-11953/12552      North American P-51K-10-NT Mustang
            c/n 111-30086/30685.  600 aircraft
44-12553/12852      North American P-51K-15-NT Mustang
            c/n 111-30686/30885, 111-36036/36135.  300 aircraft

The Dallas plant also built 1500 P-51Ks, which differed from the P-51D in having an 11-foot diameter Aeroproducts propeller in place of the 11 feet 2 inch diameter Hamilton Standard unit. These were all known as NA-111 by the company. The P-51K had a slightly inferior performance to that of the P-51D. Rocket stubs were introduced on the -10-NT and subsequent batches of the K production line at Dallas.

The Royal Air Force received 281 Ds and 594 Ks, designating them Mustang IV and Mustang IVA respectively. The type did not enter RAF service until September 1944, with the earlier Mustang III still remaining in active service

[Guppy35]

Aero products hollow blade prop.  Dallas "clear view" canopy the was slightly flatter to avoid distortion found in the more rounded bubble canopy, built in Dallas.  Lots of Combat K models.  Kit Carson's "Nooky Booky IV" of the 357th FG being the most well known example.

[Chalenge]

And the K was built in Dallas while the D was built in Inglewood.  Also, the prop on the K was a POS compared to the D's prop.

Yes, I didn't think the factory location actually made a difference. The prop differences were corrected early on in the manufacturing run.

The 'cuffed' versus 'non-cuffed' prop can still be found today (Glamorous Glennis for instance).

[Guppy35]

Yes, I didn't think the factory location actually made a difference. The prop differences were corrected early on in the manufacturing run.

The 'cuffed' versus 'non-cuffed' prop can still be found today (Glamorous Glennis for instance).

There was an un-cuffed Hamilton Standard Prop that is seen often on surviving Mustangs. It's open to debate as to whether any of those props made it on to wartime P-51s.   That is different then the Aeroproducts hollow blade prop used on the K model.  It suffered issues with vibration problems due to that prop.

There is one restored K model flying with the Aeroproducts propeller.  It's a PTO vet named "Fragile but Agile."

You can see that prop on the image below.  Different than the uncuffed blade seen on most Mustangs.

[Chalenge]

According to Gruenhagen (Mustang: The Story of the P-51 Fighter) the Dallas Mustangs were being put through a flight performance check at Hensley Field in Texas, and the test pilots were failing Mustangs at less than a 19% rate, until September 1944. What is not clear is in the details of the pitch change mechanism and whether the D and K models had the same mechanism, but it was the prop itself that was the problem.

The Material Division sent out an engineering team to the Texas plant and there they installed vibrometers to check for problems. The Aeroproducts prop had been chosen so that production could be sped up, but it actually slowed down production because the props needed to be weighed and matched in sets before they could be mounted. No Mustangs with problematic props were shipped overseas, and even the Mustang IVs were held back until the propeller problem was fixed.

[Guppy35]

Apparently some must have slipped through as there is anecdotal evidence from the 8th of propeller vibration issues with the K.  Obviously they saw combat so it couldn't have been too serious but I don't see much photo evidence of the Aeroproducts prop on postwar Mustangs still in service

[MiloMorai]

the props needed to be weighed and matched in sets before they could be mounted

Isn't that standard procedure for any prop?

[Chalenge]

You would think, but kind of sounds like there was some mixup involved, but what exactly is not mentioned in the book I have.

[earl1937]

Apparently some must have slipped through as there is anecdotal evidence from the 8th of propeller vibration issues with the K.  Obviously they saw combat so it couldn't have been too serious but I don't see much photo evidence of the Aeroproducts prop on postwar Mustangs still in service

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.   

[Guppy35]

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.

Hate to differ with you Earl but you are mixing something up here.  The P-51K was the Dallas built D model with Aeroproducts prop and slightly flatter bubble canopy.  Basically it wasthe same set up as the Inglewood P-51B to the Dallas built 51C.  Same bird essentially.

Cavalier 51s were much later as an attempt to market rebuilt 51 as a COIN aircraft in the early 60s.

[Chalenge]

Actually, what Earl is describing is a mix of Mustang stories, some of which were never true. Even the 'H' model had the wing LE fillet removed, not enlarged. Likewise, the landing gear was lighter, not heavier, as this was part of the Mustang total redesign. The 'H' was the fastest propeller aircraft of WWII, but it did not see action. The whole purpose of the redesign was to produce an aircraft that would be faster to maintain, and repair, but it was no better at ground attack than the earlier versions (except the A36 type, which was superior).

Next I expect to hear how the F-82 is two Mustangs bolted together, which is also untrue.