While lending an occasional helping hand to David Boyd during the final preparation of his 1928 (design) Pietenpol airplane, I couldn’t help but marvel at the wood structure.
Woodworking is fun for the majority of us. Making or restoring furniture can be accomplished by most of us. We can do much more with wood like build a boat or an airplane.
|Fun woodworking. Dog compliments David Boyd on a job well done.|
In the late 1920’ and early 1930’s homebuilt aircraft designs became documented with plans and publications. One publication, the Flying and Glider Manual has been brought back to life by the Experimental Aircraft Association (EAA). At the time of this writing, typing ‘flying and glider manual’ in the search box on their site brings up 5 manuals priced cheap at $7 each. Get all five for $30.
These 70+ page books are a joy to own whether or not you are into aviation. They are filled with 1930’s style pictures and drawings, billions of illustrations, detailed wood and metal working techniques plus very interesting engine modification instructions. … great coffee table books which you and your guests will enjoy.
|Fun, cheap books available from the EAA’s online store.|
But, as usual, you got me off the subject … Can you build an airplane out of wood?
Enjoy the following pictures and descriptions of David Boyd’s Pietenpol airplane project … but first some background.
Early engines affordable to the homebuilder produced 40 horsepower or less. They were often converted car or motorcycle engines. Aircraft had to be built light and use high lift (but slow speed) airfoils in their wings.
|Ford Model A car engine powers this Pietenpol. There is a radiator in front of the pilot. (From EAA book).|
Mild steel tubing was readily available but many aircraft were designed with wood frames simply to make the job of the homebuilder easier. Where the engine mount, landing gear, wing struts and other attachments are made, the builder did have to make thin steel plates to help transfer the loads from attachment bolts.
Cut and Glue Your Wood
|Fuselage side (two sides required). Cutout in one side will allow your passenger to get in easier.|
|Cross members added between fuselage sides.|
|Could have shown you the fuselage plans first, but seeing the frames may make it easier for you to understand these plans. (From EAA book).|
|After consulting plans, jigs are made to form the wing ribs. Looks like blocks of wood screwed into a plywood base will hold the wing rib pieces.|
|Wing ribs slid over the wing spars. David Boyd feels accomplishment.|
|Horizontal stabilizer in jig. The tail feathers of an airplane along with ailerons on the wing give you control.|
|Horizontal stabilizer with elevator halves. The elevators give you nose up/down control.|
|Vertical stabilizer and rudder. Rudder gives you nose left/right control. Same as a boat.|
|Seat frames are added. Hope Dave covers the frame with thin plywood. Looks uncomfortable as is.|
|Landing gear viewed from the rear. It pivots out from where it bolts to steel fuselage fittings. Springs absorb shock. Brake lines (small airplane brake fluid is red) go from pilot’s rudder pedals to the wheel brakes.|
|Sprung tail wheel assembly. Original design just had a tail skid … just fine for the airports (farm fields) of 1928. Bellcrank above tail wheel gives ground steering via cables from rudder pedals.|
|Fuel tank. Most builders have a professional weld these up.|
|Brackets made from steel. These may be for supporting wires which hold the structure together. Just hacksaw them out of thin steel.|
|Bellcranks transfer flight control from your control stick and rudder pedals to the control surfaces (wing ailerons, elevator and rudder) via control cables. Thin steel cut, formed and drilled during this operation.|
|Cockpit controls. Control stick and (foot) rudder pedals plus engine controls on the left side of the cockpit. Moving the control stick right/left controls the ailerons via cables/bellcranks. Moving the stick forward/back controls the elevators via cables/bellcranks.|
|Firewall attached to the front of the fuselage. Galvanized steel sheet can be used as well as stainless steel sheet.|
|Engine mounted to firewall. Everyone likes to give David Boyd (pretend) ribbing for not using a Ford Model A car engine as used on the original. Instead he uses a modern (1940’s) Continental A-65, 65 horsepower engine with dual ignition system.|
Try Your Plane on for Size
|Dave tries the Pietenpol on for size.|
|Seeing a pretty Pietenpol at a fly-in can be motivating during a project.|
|Original specifications for the Pietenpol. (From EAA book).|
Ready for Covering
|Before covering with fabric, Dave ensures that details have been accomplished. Also there will be lots of sanding where fabric contacts the frame. You want a smooth surface.|
|Nice close-up of the fuselage just to the rear of the pilot’s cockpit.|
|Blind nuts for things attached inside fuselage are added before covering.|
|Begin covering. Modern covering methods allow gluing the covering to the airframe. Modern fabrics of Dacron and polyester are used instead of good ‘ole cotton which was used until the 1970’s. Linen was used before cotton.|
|Bottom of a covered wing. Extra strips of fabric are added over the ribs. Round ‘patches’ are inspection rings covered with another round piece of fabric. The fabric on the inside of these rings will be cut out for inspection and replace with round aluminum inspection plates.|
|Closeup of inspection rings as well as doubling of covering where appropriate.|
|General views of the Pietenpol from 1932 ‘Flying and Glider Manual’ available from the EAA webstore. Enjoy the designs in these cheap, enjoyable publications.|
Thanks Dave for sharing your pictures with us.
You know, you could always build a simplified little airplane on a tricycle frame for your kids. They love sitting in airplane cockpits.