P-51D (oz2017)

About this Plan

P-51D Mustang. Sport scale / pattern model for .60 power.

Quote: "I decided to go ahead and design a P-51D of my own. As a source, I obtained the Morgan P-51 book which has a set of factory three-views in it with body cross-sections and also a Monogram plastic model of the P-51D (kit No. PA-77). In addition, at our local airport a privately owned P-51D was available so that I was able to compare my own plans and the real aircraft.

Checking the plans of the P-51, I discovered to my delight that the moments were almost identical with those of a Class III Orion (oz927), the only difference being the nose moment arm was about one inch longer than that of the Orion. However, the relationship wing to elevator is nearly the same. Therefore, I decided to build an aircraft of roughly the same general size as an Orion, One other consideration was to draw it of such a size that the engine could be completely cowled. There is nothing more annoying to me than to see a scale aircraft with a big model airplane engine cylinder banging out where it doesn't belong.

Although the moment ratios of the P-51 are nearly perfect for a model airplane, the airplane is typical of World War II fighters in that there is almost a one-to-one ratio of wing span to body length (37' to 32') which results in rather large fuselages for a reasonable amount of wing area on a model airplane. To get around this problem, I cheated just slightly in the design of the wing as it was lengthened approximately two inches on each panel and one inch of chord added to the wing. Such a difference is so slight that unless one actually measures the plans, computes the wing span to body-length ratio for both the airplane and the plans, one would not be able to detect this difference.

In addition, for model airplane flying, one needs a slightly larger elevator than is true of the World War II fighter planes. Here again, by maintaining the same ratio between tip-chord and center line chord of the elevator, the scale illusion is maintained. Unless one measures with a calipers, you will be unable to detect that the elevator is not scale size as it is proportioned properly.

Other than these two slight deviations in the basic P-51 design, there have been no variations from scale in this model. I am sure that these deviations are smaller than than typically encountered in the usual scale event, let alone in the multi-stunt event.

Before discussing the construction of the P-51, a word or two about the resulting flying characteristics are in order. The actual P-51 is very sensitive to the controls and I also find it true of the model. I find that with my Digitrio it requires only very slight stick pressures to obtain various acrobatic maneuvers. It is not an airplane where one hauls the stick from corner to corner. If you do, you will find your aircraft is all over the sky.

After having read the description of flying a P-51 in the Morgan book, I find that my scale P-51 handles much the same as the real aircraft. Rolls are performed with very minute pressures on the stick from one side to the other, for loops, one merely puts back the pressure on the stick and around she goes.

One of the most spectacular ma-neuvers with this P-51 is to do a low fly-by. I usually do a 1800" overhead approach and bring it down off the run-way about two or three feet at full bore and then pull up doing a victory roll on the fly-out. Members of our Madison Area Radio Control Clay who have been P-51 jockeys are swept with a wave of nostalgia as this maneuver is performed.

Touch and go's with this aircraft are also extremely nice as the P-51 tends to settle in in a rather flat attitude, the landing gear looking as if it is reaching for the ground. As was the case with the real P-51, you do not dare firewall the throttle to get off the ground to continue a touch and go. If you do, you will very quickly discover the aircraft rolling sharply to the left and snagging a wing tip. Many a real P-51 pilot met his end with this maneuver, However, if the throttle is eased forward gradually and air speed built up properly, the aircraft goes straight on out in a normal touch and go.

I also find that with a scale-type aircraft it is much more impressive to fly close in so people can see the canopy, the landing gear details and the registration numbers as the aircraft is flying by.

My P-51 was powered with a K&B 45, which is less than optimum power. I would strongly Suggest putting in a Supertigre .56 or possibly one of the new .60-size engines in order to get it to go through the vertical-eight with a little more ease..."

Update 08/11/2014: Replaced this plan with a clearer scan, thanks to MJB.

Quote: "Hi Steve; Attached are 2 files for Frank Baker's P-51D from RCM. I scanned these from original full size prints I have owned for about 30 years, and stitched them together as best as I could using the Hogal method. This should be an improvement over the current plans in your file. Best Regards from Canada."

Update 03/07/2017: added missing pages to article, thanks to RFJ.

Supplementary file notes

Article (complete).

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