Flying Models Centerfold Plan - November 2010

Dewoitine D-332 Airliner

In the age of air transport when tri-motors were the rage,
this design was one of the most elegant and exciting

By Dave Stott/Photos by Mark Finemann

Progenitor of some of the sleekest long-range airliners ever to cross the Pyrenees Mountains, the Dewoitine D-332 possesses a history to excite the imagination. Its aerodynamic cleanliness and classic lines will make it a worthy addition to a modeler's fleet. There is even a choice of color schemes. Originally the 332 was painted an emerald green and christened "Emeraude." In this livery it made a number of promotional flights throughout Europe, Russia, North and West Africa, and as far as French Indo China. Only four months after the first flight, Air France bought the first airliner in November of 1933. (The Douglas DC-1 first flew on July 1, 1933 and the Boeing 247 on February 8, 1933.) It was then painted all silver.

Unfortunately, the 332 crashed in January 1934 in deplorable weather conditions returning to France from a flight to Saigon. So impressed was Air France with the D-332 that an order was placed for four of the new and slightly larger D-333. Outwardly, this D-333 looked just about identical to the 332. The series culminated with Air France acquiring twenty-nine of the D-338, the final evolutionary design.

The model presented here was designed for outdoor flying and to conform to the Pseudo Dime Scale category of Flying Aces Club competition. It also lends itself to a reduction in size to fit Peanut Scale requirements. In this case, wood size could be reduced accordingly in the interest of weight saving. If a modeler were to reduce it to Peanut size, it is recommended to to reduce the fin at a lesser rate to ensure directional stability.

A look at the bare bones will show that the model's structure isn't all that complex. Even the nacelles are fairly simple to incorporate.

In spite of being a tri-motor, the model itself offers nothing unusual in the manner of its structure. Study the plan well before you begin construction and keep yourself familiar with it as building progresses. Refer back to this text as well. The accuracy of the patterns given for the stiff paper parts if dependent on the accuracy of assembly. But, you need no go hard on their fitting. After all, it is only a Pseudo Dimer. The dummy props for the outboard engines can be made very durable by making them two-ply and annointing them with CyA, which case hardens them. It is most important that you build in the washout of the outer wing panels. This feature is essential to ease of flight trimming and performance.

Before final assembly, make a dry run in fitting the outboard engine nacelles. Make sure that the motor cowl is lined up properly when the aft part of former C-N is in contact with wing rib B. And don't forget to make left and right hand wheel spats. Is is a good idea to make a trial fit of these parts before you cover them and the wing. SP-1 must be tilted to match the dihedral angle of the wing so the spats will stand vertically when viewed from the front.

To avoid putting shins behind the nose cowl to obtain thrust line offset, try to drill in seven degrees of down, and two degrees of right thrust. This is equivalent to a 3/32 shim placed behind the nose block at the two o'clock position when viewed from the front. You may still have to add a thin shim somewhere to achieve the offer your particular model requires, as no two models are hardly ever exactly alike. Note that there are no stringers between formers F3 and F4. This is to keep the interior of the nose as smooth as possible so no rubber knots will get hung up on structure. The fuselage formers through F6 are relieved for the same reason.

The propeller used was carved from a balsa blank 3/8 x 9/16 x 4.5 inches. Ballast consisted of three BBs pushed into the back of the bottom of the nose cowl. If the builder does not want to carve a prop, the small silver-gray plastic prop of 4.8 inches made by Sig may be tried as a substitute (Sig refers to this as a 5-inch prop). In this case, as much nose ballast may not be unnecessary, perhaps even none at all. If the model becomes too nose-heavy, try scraping the plastic prop with a single-edge blade to get rid of excess material and weight.

It is not recommended to use a larger diameter prop. This will result in the need for more power and an increase in fin area. By keeping the power and fin size minimal, the model may be made to turn either left or right under power without danger of spiral instability. The model's performance with the balsa prop and one 12-inch loop of 3/32 FAI Tan II or Super Sport will be found quite enough.

This plan originally appeared in the November 2005 issue of Flying Models.

To print a 1:1 copy of the plan you must have a printer attached to your computer that can print an 11 x 17 page. Some plans are 1:1 on 8.5 x 11 size paper and will be noted on the plan. If you do not have a printer, you can download and save the PDF to a disc or flash drive, then bring it to a copy center for them to reproduce.