Pete N Rand (oz7912)

About this Plan

Pete N Rand. Semi-scale Pietenpol Air Camper model, for simple RC (using the Rand LR-3 actuator) Galloping Ghost and .10 power.

Quote: "Wagger rose and removed his boss from the stool by a deft application of a cold nose, then clambered up to face the drawing board. Hand me the ruler and T-square, Smilin' Jack, and we shall make short shrift of getting you a nice nostalgic Pietenpol for your baseball field.

One of the first problems (Wagger explained, as he rested an outsized paw on the drawing board) is that the wing causes most of the drag on any aircraft. Therefore, it should be directly behind the device causing the pull; that is, the engine. If, however it is located at some height above the engine there will be a considerable force tending to rotate the aircraft upward. Our Pietenpol has a parasol-mounted wing, and you can't get a wing any higher than that; therefore, I would expect our Pietenpol to be very mushy and 'stally' in powered flight.

The second problem (Wagger went on) is the inherent characteristic of the Rand LR-3 actuator we are now using in our Min-X and Rand Galloping Ghost system of single-channel control. As you may recall from the Randwagon experiments, the LR-3 spends more time in the 'up' position while changing engine speeds than we would like. This is evidenced as a 'jump' and can put the aircraft into some dangerous flight attitudes when near the ground.

Thirdly, we have found that airfoils of the flat bottomed, high lift variety have too much lift and give a climbing tendency at higher air speeds. This lift is also hard to 'turn off' with elevator action since a flat-bottom airfoil will develop lift even at negative angles of attack; this condition is not compatible with the limited elevator action obtainable with GG systems.

Other minor problems we should keep in mind while modifying the Pietenpol for Galloping Ghost flight are:

1. The size of the rudder and elevator is much too large for flapping. They should be reduced in both size and travel.
2. The availability of an engine throttle and tailwiteel indicates we might be able to use ground steering just like the big boys if we can lick the tendency of the tail wheel to wiggle the aircraft from its pulsing action.
3. The big flat tail surfaces lend themselves to flat construction which un-fortunately is prone to ground dam-age, warping, and stalling during flight. I would prefer to use symmetrical airfoils in them, but that calls for heavier structure which we can't tolerate because of the short nose. Therefore, we had better use the 'Willard-Top Flight' type of hollow balsa construction of these surfaces.
4. The scale landing gear is very close to the center of gravity which spells nose-over trouble when flying from our grass field. Well have to move it up, out, and forward as far as practicable.

Wagger settled himself at the drawing board and smoothed the vellum carefully. Now, mighty chieftain, pay close attention while we draw up some quick plans for this highly modified Pietenpol which we will all the Pete'n'Rand from now on to indicate it is only semi-scale. I'll pencil building notes by the parts as we solve problems to eliminate the usual long description of 'cement tab A to slot B while holding with nose X' details. So saying, the frowning dog began to draw while giving this dissertation:

We'll start with conventional fuselage sides (shown between the heavy lines) to which we glue the front doublers and the rear structure of lk square balsa. Notice that we have first bent the wing-mount wire cabana to shape and fastened them to the inside of the doublers with lacing and epoxy before gluing the doublers to the sides. The two sides are then assembled with cross-bracing and bulkhead Ft. The engine mount is sawed from a scrap piece of oak flooring material; notice it has two pro-jecting ears which key it into F1. Appropriate balsa side and bottom blocks are now chosen for the nose; after everything is liberally coated with white glue, all blocks and engine mount are slid into place and checked for alignment before clamping firmly. When they are dry we contour the nose. Add the bottom sheeting consisting of both plywood and balsa. Set aside to dry.

We'll make a light but airfoiled stabilizer by using the hollow method. Place two lr square strips over the plan where the lead-ing and trailing edges would normally be. Place the skin over the top view, apply cement to the ribs and press them into place while pinning them to the workbench. Add the center structure, let dry, taper skin edges and then add the top skin. Remove from plans, add tip blocks and then sand structure. Build the vertical fin in the same fashion and then glue it accurately and securely to stabilizer. Return to the fuselage. Add the stabilizer platform and dowels. Mount the tail surfaces with rubber bands. Fabricate the rudder and elevator mount the control horns and then use masking tape to fasten the control surfaces to the main tail temporarily. The Rand LR-3 actuator can now be installed; this will allow us to design and fit our bellcranks and push rods..."

Quote: "Hi Steve, I scaled and cleaned this one up for you, was posted on RCGroups by RFJ."

Direct submission to Outerzone.

Supplementary file notes

Article pages, text and pics, thanks to hlsat.

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