Early P-51/Mustangs - Data and Paper Model Comments

[member_3]

I recently began (for my own amusement) the recoloring of some P-51 models by Dr. Emil Zarkov and Marek Pacynski. Since I had a number of excellent P-51 references and drawings available I also intended to improve the models, if possible. I quickly discovered that the accuracy of most of the paper models available is somewhat lacking. That prompted this overly long (and boring to most) dissertation on the early RAF Mustang and USAAC P-51 models and various paper renderings of them. Maybe it will help to raise the accuracy and detailing of future models.

My primary references were the excellent "Detail & Scale" series as well as Mushroom Publications incredible book on the P-51D. Much info was also gleaned from the P-51 SIG on the web and 1/32 scale p*****c models by Hasegawa and Dragon. Any errors of fact are mine and mine alone. I will present opinions regarding the accuracy of several designers' models. These are presented as opportunities for present and future designers to improve their models. Please, please do not interpret them as a personal attack!

Onward, then...

Mustang I (620 built) - RAF only, 2 were taken from the British order as XP-51s. 2 x .50 cal chin mounted, 2 x .50 cal and 4 x .30 cal wing mounted. Allison engine. Carburetor scoop thin and long on top of nose. Belly cooling air scoop shallow with hinged forward lower section to increase intake size. Small gap between top of scoop and wing. Landing light on each wing leading edge. Curtiss-Electric 3-blade 10'6" (early) or 10'9" (late) prop. L-shaped pitot tube under right wing.

MODELS - I am not aware of any paper models of the Mustang I.

P-51/Mustang Ia (55 P-51 plus 93 Mustang Ia plus 2 as XP-51B for Merlin engine tests) - 4 x 20mm cannon wing mounted. Allison engine. Carburetor scoop thin and long on top of nose, constant width in plan view. Belly cooling air scoop shallow with hinged forward lower section to increase intake size. Small gap between top of scoop and wing. Landing light on each wing leading edge. Curtiss-Electric 3-blade 10'9" prop. L-shaped pitot tube under right wing.

MODELS - AirDave has done a 1:33 scale repaint and modification of a Marek 1:50 P-51B/C (Mustang III) model as one of his "Rare & Unusual Color Schemes" series in "dazzle" disruptive camouflage. It is identified as a P-51A but the photo (and the model) are a cannon-armed P-51. AirDave added landing lights, cannon (located incorrectly - see comments after P-51B/P-51C/Mustang III below) and top-mounted carburetor air scoop. The belly scoop is slightly different from the Marek original but still does not seem to have the correct profile and gap between it and the wing. The propellor blades are Hamilton Standard, not the correct Curtiss-Electric. Other changes include "photo realistic" canopy panels, wheels and (2-dimensional) wheel wells.

A-36A (500 built) - USAAC only. The names "Apache" and "Invader" were both applied unofficially (and unsuccessfully) but the RAF "Mustang" name was so firmly entrenched that it was applied to the A-36 also. While officially designated A-36A the lack of any further development resulted in the "A" suffix usually being dropped. Dive brakes on top and bottom of wings. Two underwing pylons. 2 x .50 cal chin mounted, 4 x .50 cal wing mounted. Allison engine. Carburetor scoop thick and long on top of nose, tapering in plan view. Belly cooling air scoop shallow with fixed intake size. Small gap between top of scoop and wing. Two landing lights in one unit on left wing leading edge. Curtiss-Electric 3-blade 10'9" prop. Boom style pitot tube on right wing leading edge (because of dive brakes.)

MODELS - Thai Paperworks (NOBI) has a 1:48 scale A-36A. This is a simplistic model with no cockpit interior and no wheel wells. The dive brakes are poorly depicted. This model suffers from the same navigation light and wing armament problems discussed in the notes below. The landing light is correctly depicted.

P-51A/Mustang II (260 P-51A plus 50 Mustang II) - 4 x .50 cal wing mounted. Allison engine. Carburetor scoop thick and long on top of nose, tapering in plan view. Belly cooling air scoop shallow with fixed intake size. Small gap between top of scoop and wing. Single landing light on left wing leading edge. Curtiss-Electric 3-blade 10'9" prop. L-shaped pitot tube under right wing. Two underwing pylons.

MODELS - I am not aware of any paper models of the P-51A/Mustang II.

P-51B/P-51C/Mustang III (1988 B, 1750 C built, Mustang III included in those totals) - The P-51B was built in California and the identical P-51C was built at Dallas, Texas. 4 x .50 cal wing mounted. Merlin engine. Carburetor scoop relocated under the nose. Belly cooling air scoop deepened with fixed intake size. Larger gap between top of scoop and wing. Single landing light on left wing leading edge. Hamilton Standard 4-blade 11'2" prop (delivered "cuffed" but the cuffs were sometimes removed in the field.) L-shaped pitot tube under right wing. Two underwing pylons.

MODELS - Marek has done several models, all in 1:50 scale. There is a P-51B of COL "Tex" Hill, a German-captured P-51B and a Mustang III of CPT E. Horbaczewski, 315 Sqn., RAF. In addition, eCardmodels offers a 1:50 repaint of the P-51B of COL "Bill" Creech, 528th FS, 311th FG. AirDave is making a
career of enlarging and repainting Marek models and has done sixteen 1:33 scale P-51s at last count. There are twelve in his "Tuskegee Airmen 1, 2 and 3" Series plus a German-captured P-51B, a Swiss interned P-51B, and a Japanese-captured P-51B (plus the fore-mentioned P-51 in "dazzle" camouflage.) Last but not least, Halinski has a Mustang III in 1:33 scale. The original Marek models have no cockpit or wheel wells and are missing such details as landing lights, pitot tube, underwing pylons and navigation lights. AirDave's P-51B/C repaints have an extra landing light on the right wing and do not have the red/amber/green identification lights under the right wing tip (the Marek original has them, but they are not colored.) Like the P-51 above, they have the "photo realistic" canopy panels, wheels and (2-dimensional) wheel wells. The Halinski Mustang III is definitely the most detailed (and most accurate.)

NOTE: The wing guns on all models through the P-51C/Mustang III were mounted in a plane parallel to the ground, not on the dihedral line which makes the outer gun lower on the wing leading edge than the inboard gun. The only models that get this right are Halinski's Mustang III and all of AirDave's P-51B/Cs. AirDave's P-51 has the outer cannons incorrectly positioned on the dihedral line.

NOTE: The Allison-engined aircraft did not have the same exhaust pipes and surrounding panels as the Merlin-engined birds. Allison engines had pipes that were flattened vertically toward the end and the half panels above and below the exhausts formed one long slot accommodating all six tubes. Merlin engines had pipes that were circular at the end and there was a one piece interior plate pierced with six individual holes for the pipes and "dished" or bulged outward for most of its length. The outer upper and lower half panels were similar to the Allison-engined ones and the bulged portion of the inner plate is quite noticeable. The inner plate was sometimes removed in the field but it is hard to say how commonplace this practice was. No paper model gets the Merlin exhaust assembly with the bulged inner plate correct (not even Dr. Zarkov's beautiful P-51D models.) The Halinski model appears to depict a Mustang III with the inner plate removed.

NOTE: The recognition lights (red/amber/green) could only be turned on when airborne since they burned out from heat without airflow over them. The green light's lens appeared dark blue when not illuminated as did the starboard navigation light's lens.

NOTE: The inner landing gear doors on these early models were open only to extend/retract the main landing gear because they disturbed the airflow to the belly cooler which could result in engine overheating. The doors could be manually released for maintenance on the ground. The "normal" state for a model with its gear down should have these doors in the closed position.

Let the flaming begin...

[Don Boose]

A very thorough analysis, Ron. I enjoyed reading it. It would be nice to have more models of the earlier Mustangs available.

Perhaps your accuracy fixes can be incorporated into future revisions of the popular Marek and Thai Paper Work models (as I recall, the TPW P-51 was a free download gift from Nobi).

Don

[birder]

Nice summary and research we can all use Ron! In looking at the early p-51's Allison powered the nose shape is different to my eye also, and I think the forward sweep of the wing root is also less pronounced, do you agree?

[birder]

Oh- Rigby made a Apache, was simple to be sure and full of inaccuracies of the early models, may have been designed pre-merlin?

[member_3]

The wing structure on all the models discussed were the same (with the obvious exception of the A-36 dive brakes.) The P-51D introduced a new wing and I agree that the root forward sweep seems greater than on the early models. The nose contour differences are more related to carburetor intake shape and placement than they are to engine type, I believe.

A minor note - all the MG-armed models had three gun bays in each wing - even though only the Mustang I used all of them.

An apology to Maly Modelarz who also has a Mustang III model in 1:33 scale but I am not familiar enough with it to comment on its accuracy.

[Bomarc]

Nice summary Ron. What is this "P-51 SIG" you speak of.....?

Anyway, the P-51D did indeed introduce changes to the wing that resulted in a longer chord as a result of the larger "crank" at the wing root compared to P-51C and earlier models. Also, the "D" wing feature redesigned "clam shell" wheel doors (obvious differences compared to earlier models) and strut doors (not so obvious).

Speaking of wings, one of the biggest and most often overlooked differences between Allison and Merlin engined Mustangs is the fact that NAA lowered the wing 3 inches to accommodate the Merlin. Just slapping on a three blade prop and moving the carb "smile" to the top of the nose of a P-51B model barely scratches the surface of all the differences between Allison and Merlin Mustangs.

I would hope the Eastern European model companies (are you listening Halinski?!) would come out with a fresh from the ground up Allison Mustang some day.

Mike

[RyanShort]

I think Fly Model also made a P-51A that was paired with a Fiat G.55.
Another Fiddlers Greenish P-51A model is available here: http://www.thepaperairplanecompany.c...10/1732239.htm

Ryan

[cdavenport]

Another of my impertinent ideas.

Armed with all that information, why not join forces with some our more prominent aircraft designers and design and build the ultimate P-51?

It seems to me that one could design a plethora of Merlin-engined versions based on a single fuselage/flying surface design. Change the nose section and you have the Allison powered versions.

It just so happens that there is a nice 1/32 scale Merlin engine available for free.

Let's get crackin'!

[wag]

There's been some discussion on some of the plastic model forums about the position of the flaps and inner LG doors when the airplane was parked. These were hydralic powered and on the Merlin engined versions the flaps and doors would droop down after the airplane had been shut off awhile. Did the Allison engined versions have a mechanical up-lock? Also if any designers out there need a 3-D reference for the early mustangs the Accurate Miniatures plastic kits are excellent.
Wayne

[airdave]

AirDave is making a
career of enlarging and repainting Marek models and has done sixteen 1:33 scale P-51s at last count.

ha hahahahahaha ha
you're a funny guy!


hey, half the things you say I got wrong are things I never changed from marek's original.
Thats one of the reasons I did 'em ('cause there are so many inaccuracies)
but they're still not bad for cheap paper models!?

you are right, there are many things I don't know about these P-51s
along with many other aircraft...I'm an artist, and I love the pretty colours, the fantastic paint schemes and fabulous artwork on some of these planes!

I know these Marek kits are not super technically accurate models but if there is anything I can improve on, alter or even remove from my repaints to make the kits more accurate and/or more appealing...please don't hesitate to point out the changes I should make!

If I can get more info (ie pictures) on these items, I will attempt to make updates to the existing kits:
-Wing Cannon locations for the Dazzle Mustang (P-51A)
-prop Blades (Curtis Electric?)
-an extra landing light on right Wing of the B/C Mustangs?? (I didn't add this?)
-missing IDENT lights on the right wing tip