Warbird Information Exchange

What is the difference between the P-51D & P-51K? I looked over the stats and they seem the same. I assume that is like the B & C in that they were made at a different plant. Is that correct? And is “Fenesi” a D or K model?

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www.tailhookstudio.com

I don't recall if there was also a plant difference, but the D came equiped with a Hamilton Standard prop, and the K came with an Aeroproducts prop.

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Dan Johnson

Ds were built at Inglewood, CA, and Ks were built in Dallas, TX.

In addition the the propellers being sometimes different, there was also a slight difference in the canopy, with the K model typically having an extra hump at the back. Not all Ks had the hump, however.

The reason generally given for the difference in canopy shape has to do apparently with different suppliers/manufacturers between Dallas and Inglewood.

D's were also built in Dallas

Hi


the only real difference was the Aeroproducts propeller of the P-51K series built at Dallas, TX.
This propeller type (Aeroproducts A-542-A1, diameter 11 feet, blades A20-156-24M) was introduced as alternative type because at one time Hamilton Standard's output (supplier of the HS 24D50-87 cuffed blade type, diameter 11 feet 2 inches, blades 6523A-24) was stretched to the limit .
Since the K-type propeller (hollow blades, rounded tip, uncuffed) led to vibrations and resulting oil leaks, this type was at one point discontinued, and the Dallas plant continued to build P-51's with the regular HS 24D50 unit. The designation of the Dallas produced K's was P-51K-xx-NT, the following D-models became P-51D-xx-NT's, while all Inglewood, CA, produced variants hat the -NA suffix.

The myth with the 'Dallas' canopy is only due to different suppliers (sub-contractors to NAA). Remember that the canopies were blown into shape and while setting up the Dallas production line, the shape of the canopy for the K's was slightly changed for additional sub-contractors, allowing a bit more headroom for the pilots. Early K's had the same (original) type installed as the D's coming off the line at Inglewood, CA.
Fact is that also at the Inglewood, CA, line, at one stage a slightly different shaped canopy type was introduced, rather similar to the 'Dallas type'.

Moreover, the canopies were interchangeable.

In post-war years, it also happened very often, that due to the proplems with the Aeroproducts propellers, surviving K's (mainly Recon versions) were re-fitted with Hamilton Standard units - this could easily be accomplished - in addition to the propeller only the reduction gear had to be exchanged, too. - And in a few cases, the exact opposite happened, i.e. a D-model was seen with the Aeroproducts propeller.

Late during production, and post-WW2, a new type of the Hamilton Standard propeller was introduced, more precisely the blade, type:

This was the so-called 'paddle blade' - blade type 6547A-6, uncuffed with squared-off tips - the unit seen mostly on today's warbirds.
Surviving Dallas produced K-models also were re-equipped with this new HS unit.

Summary:

external differences between D- and K-models are only visible on the propeller, but only during or shortly after WW2. As from the late 40's, only the serial number could tell where an aircraft had been produced, i.e. NT-suffix for Dallas and -NA suffix for Inglewood.

I have looked at thousands of P-51 photographs and unless I have a clear view of the serial-number, either on the tail or on the data-block below the cockpit, there is no way of telling the external difference between a D- and a K-model.

Just my 2 cents
Martin / Swiss Mustangs