Waco YMF - 5

A company called "Classic Aircraft" based in Lansing, Michigan has been building replica's of the WACO YMF-5. In talking with the shop foreman recently I was told that they have back orders for eighteen of them that sell around a $150,000.00 a piece. The replica Waco's are powered by Jacob Radials.

Several years ago when the IMAA Festival was held in the Lansing area, they made arrangements to have the prototype on display at the Festival site, and made arrangements for a factory tour on Saturday morning for anyone who wanted to see them under construction.

Jim Pepino of Scale Plans-Photo Service jumped at the chance and must have taken hundreds of pictures. From those photo's Jim developed a beautiful set of plans for a quarter scale version of the WACO YMF-5.

The wing span is 90 inches with a wing area around 2,350 squares. Jim's plan project the weight at 22 to 25 pounds, at 25 pounds the wing loading is 24.50 ounces so you have a floater, the same as the Pica's Waco. (Click on Any Photo to Enlarge)

Jim Pepino's 25% Scale Plans

 First Sheet

The first sheet has a top fuselage view and left side view. The fuselage is built using 3/8 square balsa or spruce longerons, the choice is yours, I use spruce and its it came out so nice I didn't want to cover it! Bulkheads and formers are added to the basic framework. Heavy oak beam mounts are shown on the plan, but you have the option of building and reinforcing the firewall, I used end grain balsa with 1/16 plywood front and back.

Fin and rudder are built using a 3/16" balsa sheet core, to which you add ribs. Leading edge of the rudder and trailing edge of the fin are either balsa, spruce or basswood. I find myself using more and more basswood. It is light, strong, sands easily and doesn't split easily. The scale tail wheel in the proper position and the construction is shown. The cowl with valve blisters and the wheel pants are shown and are available from Fiberglass Specialties.

The  Second Sheet

The second sheet has the left wing panels with the center sections shown. Wings have two box spars with 1/8th sheet ribs. Ailerons have 1/8th sheet cores, and are hinged at the top. I changed hinge line to scale and will be using Robart hinges that are recessed to pivot like the scale aircraft.  Ailerons can be torque rod operated, I used a servo on each and Jim suggests the Byron aileron connectors for a faster set up and take down. Both wing center sections are sheeted with 1/8th balsa. Also on this plan sheet the rear cockpit template is shown, the front cockpit cover and the door template for the front cockpit and a door template for the rear cockpit. There is also a baggage compartment immediately behind the rear cockpit on the left side. Wing interplane strut construction is also shown on this sheet.

The Third Sheet

The third sheet shows the right wing panels. All ribs are cap stripped, which makes for a much nicer finish. The stab and elevator which are constructed the same as the fin and rudder are shown. The ailerons on the real aircraft were corrugated aluminum with 36 corrugations per side. Jim suggests that these corrugations can be purchased from SIG Manufacturing, they are used on the SIG Bravo part. Aileron mass balance bracket fitting is also shown on this plan sheet.

The Forth Sheet

The forth sheet has the bulkhead drawings and the landing gear layout. The gear bent from 3/16" wire, and shock comes from a single bolt and spring on the spreader wire similar to the Byron Pitts. I firmly believe that on lager models of this size and weight you must have a good shock system. Cabane wire layout and attachment is also shown. There is also a jig for setting the wing incidence shown. Also on this aircraft there is two degrees of dihedral in both the upper and lower wings.  This set of plans can be purchased from Scale Plans and Photo Service, Greensboro, NC. This is great set of plans the pictures do there best to tell the story for you.

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