The P-51K

[Bomber_12th]

Manufactured at the NAA Dallas plant, the P-51K was a direct result of being able to produce more aircraft, faster, than Hamilton Standard were able to supply propellers. The Aeroproducts company was sourced to provide prop blades as well, but in order to mount the Aeroproducts units to the P-51, a new spinner had to be designed in order to mount them. Because of this design change, all of the Mustangs, that were otherwise identical to specific production block P-51D's, were named P-51K. Just as with the P-51D, there were different production blocks of the P-51K, the last of which was the P-51K-15-NT, which was the same as the P-51D-30-NA/P-51D-30-NT, but with the Aeroproducts prop and spinner. The vast majority of all P-51K-15-NT production was for the RAF, and as included in Warbirdsim's "Little Friends I" product, the P-51K in the screenshots below illustrates the factory delivery scheme of RAF P-51K-15-NT's, ready to be shopped out from the U.S. Instead of the top line of the data block reading "AAF SPEC. PROJ. NO.", it simply reads "UNITED KINGDOM GOV'T", as was the case. While the aircraft sports its RAF serial number (which NAA applied using the same stencils as the USAF tail numbers), the aircraft does also have a USAAF serial number assigned to it, which is present in the data block, and in the cockpit placards.

The bright marks/lines on the metal, is an authentic production detail. Wherever there were spot welds, the surface of the metal had to be absolutely clean. In order to accomplish that, fast, acid was simply brushed on where the spot welding was to occur, which etched the metal. This would show up the most, on aircraft fresh from the factory, but would tend to "fade" away over time, with wear and any polishing (which some groups did do in the field - its about pride in your aircraft, and wanting it to look and perform its best). You'll find this acid etching on most all other US manufactured aircraft during WWII as well, though it has often never been reproduced. These sorts of details have, however, become more well known in recent years, with restorations like "Happy Jack's Go Buggy". This can be seen the most, on and around the radiator intake and on the gear doors, while some of the panels the whole panel is treated. That's why the cowl panels and some others are 'brighter' and less reflective than the rest of the bare metal.

Also, speaking of finishes, at the factory the wings were always filled, sanded, primered, and painted with dull silver dope (with almost no specular quality - that tended to fade quite easily). This was done in order to maximize the "laminar airflow". The gear doors, fuel tank cover panels, and ailerons and flaps were left un-painted. The chin scoop, all of the trim tabs, and the fabric rudder were also finished in dull silver dope.

The aircraft is fitted with a late-war Dallas canopy, just as on the original example portrayed.

 

[dvj]

Your modeling is amazing!

 

[SpaceWeevil]

Your modeling is amazing!

Painting too!

 

[mohawk3]

Amazing!!!

 

[dougal]

Thanks for that info - I didn't know that.

If such a thing is even possible, I think the Aeroproducts 'K' model prop is just SOOOOO much 'prettier' than the Hamilton 'D' version. Just looks more like a prop is 'meant' to look;-)

 

[hairyspin]

Ahhhh, roundels! A treat to the eye!

 

[Bomber_12th]

I just have always thought it a cool 'sub-variant' that has seemed to be clouded in a bit of mystery for some. It's been fun to have the aircraft in the sim over almost the past year now, with its unique look. I've been sitting on several repaint ideas for the K, that hopefully I can make happen soon. <o></o>
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Here are a few K-model related photos I've pulled from my photo folders.

This, if I recall correctly (and fairly obvious by there being a number on the nose and tail), is one that was retained for state-side training.
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Here is a close-up of the unique spinner that was manufactured for mounting the Aeroproducts prop blades. You'll notice that the cut-outs are differently shaped than those of the D-model nose cone, and the construction is different as well, even though the shape is the same. You can also see the stenciled "X" mark on the upper right corner of the chin scoop - you'll find this recreated on most of the Warbirdsim P-51D/K's.
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Here are a couple of photos of factory workers posing in front of freshly manufactured P-51K's. I have many more, but they are all fairly much the same, just with different people. Note the clear signs of acid etching on the cowl panels. Sometimes it was applied to entire panels, and other times it was only applied where the lines of spot welds were to be.
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Note number 38, with an Aeroproducts prop, Dallas canopy, and Dallas-style serial number aplication (where the numbers were applied much closer together).

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Note the acid etching pattern on the gear door, compared to that of which is copied in the screenshots above.

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This is the only Mustang that flies today in original P-51K form.<o></o>
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[DagR]

Best researcher/painter in FSX ever, bravo Bomber_12th!!!!!


Best
DagR

 

[thunder100]

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Where the K's any faster or slower then the Hamilton D's ?

On the Bf-109(since Legion Condor) and on the He-219(Rechlin) my late friend told me that it mattered which engine with which prop* you got,and sometimes on the field the Novotny's got the best of all modified ones.


Roland

On 109 there were early "good" props and elder "bad" props so you had to state a landing mistake and then mount an old stock

 

[Bomber_12th]

Roland, there was no noticable difference in performance from the Hamilton Standard to the Aeroproducts prop. This was backed-up with the experience of the so-equipped restoration of "Fragile But Agile". It's the same case with the "cuff-less" Hamilton Standard props. The cuffs are meant to flow more air, close over the airframe, into the intakes, for better cooling, but I believe there was a discussion once, about how they didn't really work that well, and they didn't provide any additional thrust (though that wasn't the point in the first place). By the summer of 1945, all of the P-51D production had switched over to the square-tip cuff-less Hamilton Standard props (which you'll see on a lot of restored examples). There was actually a rather surprising photo that turned up, not too long ago, that showed one of those very late-produced P-51D's, with the square-tip cuff-less props, in the Pacific, just post VJ-Day.

Although I've said it who knows how many times over the last year or so, what I like is being able to look at the aircraft, either standing on the outside, or siting in the cockpit, and all of the proportions, the lines, the contours, the angled-degrees, etc., match in exacting detail with that of the real deal. There's no vertical or horizontal stretch to the VC, as it was all built from the bare bones up with the pure intention of getting it right from the very first day. The end result, is that there isn't this 'skewed' look of an innacurate base, with a few accurate parts added in - it just all fits together, looking just as it really is. And the same goes for the exterior, with each individual section, from the chin scoop, to the nose cone, to the way the nose of the aircraft bleeds so beautifully from the nose cone into an almost completely flat upper-cowl surface, to through the properly proportioned and modeled windscreen and canopy, to the way the spine has just a slight lip to it as it blends into the rear of the canopy. This continues to the tail, with the rather dramatic, but completely accurate angles and curves, down to the radiator intake, which was the single longest-task to model accurately, but so was done. This is completed with the authentically-recreated laminar airfoil of the wing, and the unique way in which the wing tips cap off the shape of the wings, almost 'pinched' at the forward edges. Covering this, through the textures, are all of the details as they really are, with panel lines and rivet counts that match-up 100% accurately.

As shown, every P-51B/C/D/K that rolled off the assembly line had wood floors, both under the seat, and from the seat up to the rudder pedals. The floor boards under the seat were always painted interior green. The floor boards from the seat up to the pedals were always painted with non-slide black paint, which had a fair amount of grit to it. As has shown up even in restorations, it doesn't take much to scuff the non-slide finish, and the specific wear pattern copied and shown here, wasn't just copied, as it is, from just one particular example, but there was an obvious similarity, over a number of different cockpits I looked at (circa 1946/47), to this wear pattern. The pilot always enters from the left, and thus always enters the cockpit with his right foor on the right floor board, with the most pressure and movement on the right foot. The left floor board is mostly scuffed just by the pilot's left heal. The rivets in the floor boards were painted over, factory-fresh, but after use, they begin to rub through and become exposed. The rivets shown are what fasten the wood floor plates to the metal floor plates below. There were never any kick plates on the aircraft during WWII, but in the 70's/80's/90's there was a trend for adding metal kick-plates to the floor, to help prevent damage to the floor boards.

Note the two lugs that the "Gun & Fus. Level" stencil and arrows refer to. While the aircraft is on jacks, by placing a level on these lugs, you know that the aircraft is perfectly level. Although a very small detail, you almost never see these lugs reproduced, and thus adds to the confusion behind the stencil when those lugs aren't there. The lugs and the stencils were only present on the port side (it was only there as a tool for the ground crews).

Note the tail warning radar bell with authentic placard.

 

[res non verba]

it's a pleasure to read your posts, i really enjoy reading the story behind the plane, thanks!

:ernae:

 

[thunder100]

Roland, there was no noticable difference in performance from the Hamilton Standard to the Aeroproducts prop. This was backed-up with the experience of the so-equipped restoration of "Fragile But Agile". It's the same case with the "cuff-less" Hamilton Standard props. The cuffs are meant to flow more air, close over the airframe, into the intakes, for better cooling, but I believe there was a discussion once, about how they didn't really work that well, and they didn't provide any additional thrust (though that wasn't the point in the first place). By the summer of 1945, all of the P-51D production had switched over to the square-tip cuff-less Hamilton Standard props (which you'll see on a lot of restored examples). There was actually a rather surprising photo that turned up, not too long ago, that showed one of those very late-produced P-51D's, with the square-tip cuff-less props, in the Pacific, just post VJ-Day.

Note the tail warning radar bell with authentic placard.

John you tempted me anyway-->needed the K so I bough LF1(having B/C and the fillet ones allready)
Its so beautiful

have fun

Roland

The germans are said to have better props.Nobody can prove the difference.Especially their FW190 and the D9's(whrer the blade starts more outwards.I have a degree in aerodynamics so I doubt that close airflow to the aircraft body a lot.But that would be an endless discussion(air over standstill polished aluminium causes a lot of turbulence .This increases the borderlayer and makes in fact the plane bigger by the borderlayer-non polished alumium a bit rough(think of a sharkskin (or better a polish paper)) in certain areas are faster(till Mach 0.8) but terrible for radar

 

[fliger747]

With such a beautifully researched and executed aircraft series why would someone want or need another one?

To quote from Julius Cesar..."Eh tu Brute?"

T

 

[fliger747]

To my knowledge Cuffs were mostly for additional cooling for radial engines. The FW used a different technique with a cowl mounted fan. There is some supposition that the cuffs on the P-51 were an experimental effort to improve flow to the chin and radiator scoops. I have seen some cuffs used on large turboprop engines, apparently in an effort to improve inlet flow.

T