DH Comet (oz1930)

About this Plan

DeHavilland DH.88 Comet. Control line scale model twin racer. Wingspan 32 in. For twin Cub .099 engines, or similar. Scale is 1/16.

Quote: "Famous winner of England to Australia race reappears as half-A twin. DH Comet, by Walt Musciano.

Flown by CW Scott and T Campbell Black, this sleek twin-engine beauty won the most famous air race of all time, just sixteen years ago. The bright red racer completed the 11,300-mile Mac Robertson Intercontinental Race from London, England, to Melbourne, Australia, in 70 hrs, 54 min and 18 sec, during October 20-23, 1934. Average speed for the flight over this long distance was 159.15 mph, which beat some of the finest airplane designs and pilots from all over the world.

Powered with two De Havilland Gipsy inverted, in-line, air-cooled engines, the Comet was all-wood construction. Its design data later helped inspire development of the very successful World War II DH Mosquito fighter-bomber. Although designated 'Comet' by De Havilland, the plane was christened 'Grosvenor House' (pronounced Grovnor) for the race.

The model DH Comet features simple and economical construction, convenient size for a twin-engined job as well as obvious good looks with completely enclosed engines. Built to the scale of 3/4 in to the foot, our Comet can take engines from .074 to .19 cubic inch displacement, although the .09 sizes are perfect. A 1 inch Rev-up spun aluminum spinner fits the model perfectly. We used Cub .099 engines with 6 in dia, 4 in pitch OK propellers - however, any other workable combination should prove satisfactory.

If you have hesitated to tackle a twin-engine job because of its large size, complicated structure or great expense, your troubles are over. Here's the model that is easy to transport, build, fly and is also easy on the pocketbook.

Join 1/16 x 1/2 in sheet balsa end to end to form wing panel coverings. Four covers are required; plans indicate the seams. While this is drying, cut ribs and joiner from specified stock. Cement ribs to bottom covering of both wing panels. When dry, cement joiner to ribs and covering. Dihedral will be correctly formed by joiner. Attach leading edge using plenty of cement. The lower covering trailing edge is beveled to fair into upper curvature of ribs. Cement top covering to wing. Use slow-drying cement for this purpose; cement the wing tips in place. Set aside to dry thoroughly.

Cut the four sides of engine nacelles from 1/8 sheet balsa. Select stock that can bend against grain without breaking. Cement beam mounts or LG mounts to the sides, whichever is to be used. Drill 1/16 holes first. Install bulkheads E and F and join sides at rear. Drill bulkhead E for radial mounting if required. If necessary, dampen outside of 1/8 sides with warm water to facilitate bending. Add soft balsa blocks to nacelles.

Returning to the roughly assembled wing, trim leading edge and wing tips to correct shape with sharp knife. We like the X-acto No.26 blade for this job. Sandpaper wing smooth.

Carve nacelles in same manner as wing and then sandpaper. When carving nacelles, fair them into the spinner you intend using. Bevel top of nacelle to compensate for wing dihedral (see station F). Using shim brass, fabricate two tanks as shown, or if available purchase similar tanks at your dealer..."

Update 10/4/2025: Replaced this plan with a clearer copy, scanned from fullsize at 400 dpi, thanks to dfritzke.

Direct submission to Outerzone.

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