Apache (oz13451)

About this Plan

Aerocraft Apache. Radio control sport aerobatic model for 05 electric motor (or .09 - .15 glow engine). Wingspan 44 in, wing area 340 sq in. Target AUW is 38 oz.

Direct submission to Outerzone. Cleanup by Pilgrim.

Note the supplement instructions file includes 2 pages of parts identification drawings, these show all wing ribs and formers, at reduced scale [edit: fixed now, see printwood supplement].

Note there is a 1997 review of this kit by Ron Farkas online at RCGroups see: https://www.rcgroups.com/forums/showthread.php?194487-The-Aerocraft-Apache

Quote: "The kit consists of die-cut ribs and fuselage sides, sheet and strip balsa, some plywood parts and vacuum formed plastic cowl and canopy. Wood quality was good, but a few of the die-cut ribs required the stroke of a hobby knife to release from their sheets. Formed landing gear wire, aileron torque rods, hardwood mounting blocks and an ample supply of assorted hardware items are supplied.

There are clearly drawn and accurate rolled plans and a well-organized 12 page instruction booklet. This booklet includes an itemized parts list and diagrams of the die cut sheets to assist in locating parts, although some of the diagrams have been accidentally printed as reverse images. There are no assembly photos or drawings, but that is a minor issue since the construction is quite conventional.

Considering the importance of weight savings in electric powered models, Aerocraft's choice of wood density and quality was quite good. I think their target weight of 38 oz is unrealistically low, but the model has proven to be flightworthy at 50. The long tail moment can make this model susceptible to tail heaviness. Even though I added an optional steerable tail wheel, my Apache still balanced properly by mounting all of the radio equipment as far forward as possible and stuffing a 500 mah pack behind the firewall.

The instructions and plans could be improved by being more explicit about equipment location for those builders who don't plan ahead on their own.

Construction: Although this is a entirely built-up airframe, it assembles rapidly because almost every part fits perfectly. The bottom of the tapered wing is flat behind the main spar, and thus is to be built directly on the plans. The main spars are first made from laminations of 1/16 x 1/4 and 1/8 x 1/4 balsa strip stock. This yields 3/16 x 1/4 spars that are stronger than a single piece of stripwood.

The bottom main spar is laid on the plan, followed by sheet trailing edge stock, a pre-tapered trailing edge spar, most of the ribs, shear webs, the top spar, and a 3/16 sq leading edge spar. Trimming the shear webs to fit between the top and bottom spars was a little more time consuming than just gluing them to the back of the spars..."

Update 21/9/2024: Added printwood zipfile, thanks to theshadow.

Supplementary file notes

Instructions.
Printwood zipfile.

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