Building the Zenith STOL CH701
The STOL CH 701 aircraft is built of semi-monocoque stressed-skin all-metal construction, just like modern factory-built planes, but adapted specifically for the kit builder. The airframe sections are designed and built so that the outer surface skin is part of the structure, with internal supports (ribs, bulkheads and longerons) to distribute the loads. The parts are fastened together permanently with rivets.
Sheet-metal construction is outstandingly the most widely used aircraft building method around the world, and has proven itself as an ideal aircraft building material since the early pioneering days of aviation. Modern alloys are lightweight, strong, corrosion-resistant and durable, while being easy to work with.
Building the STOL CH 701 one section at the time
Unlike many other all-metal kit aircraft, the STOL CH 701 kit is made for the first-time builder, and is simple and quick to build, requiring just basic special skills, tools or jigs to assemble in a small workshop, such as a single car garage or basement workshop. Designer Chris Heintz has been perfecting all-metal construction for homebuilders since 1974, giving Zenith Aircraft Company unparalleled experience and resources in providing complete kits for first-time builders, and renowned customer support to every builder.
Sturdy and low-fatigue aluminum alloys make the STOL CH 701 airframe very rugged and corrosion resistant. The modern 6061-T6 aluminum-alloy used in the STOL CH 701 construction is durable and corrosion resistant, ideal for even the harshest environment, and very easy to repair and maintain in the field. The owner of a STOL CH 701 is assured of a long airframe life, with minimum required maintenance, as metal is not adversely affected by ultra-violet (UV) light and temperature changes like fabrics, Dacron or composites (it’s thus feasible to tie-down the aircraft outdoors to minimize costs).
Developed for the novice kit builder, the STOL CH 701 may be built from component or complete kits, or even built from just the drawing and manuals. Building a STOL CH 701 from scratch (rather than the factory kit) necessitates more time, skills, and tools, requiring about 1,500 hours to build.
“The truest gauge by which to measure the quality of a kit and its kit manufacturing company are the number of its satisfied customers, the fine flying characteristics of all its finished aircraft, and the dedicated after-purchase support provided by the factory. By all these standards and many others too numerous to mention, Zenith Aircraft Company’s excellent reputation is well deserved. We heartily recommend to every prospective homebuilt kit buyer that he or she seriously consider the excellent aircraft produced by Zenith Aircraft, a company we’ve always found to be competently and professionally managed by genuinely qualified, dedicated people.” — editor, Sport Pilot magazine
Developed for the amateur builder, the STOL CH 701 draws upon Zenith Aircraft’s vast design and manufacturing experience. The simple stressed-skin monocoque construction uses single curvature sheet-metal skins riveted to internal structural members.
The sheet-metal skins, main wing spar, structural ribs, longerons, stiffeners and bulkheads are fastened together with Zenith’s proven riveting method using blind rivets, which are as easy to set as ‘pop’ rivets, requiring only a simple hand rivet puller. The corrosion-resistant rivets provide a permanent structural bond and tight low-profile dome finish, formed by the custom riveter head. The rivet stem becomes locked in after being set to provide a water-tight seal. The 1/8-inch and 5/32-inch blind (or sohey go together predominantly with aircraft-grade pull-stem rivets, which together with the simplicity of the design make for kits that can actually be assembled in a few hundred hours.
The sturdy main wing spar is a built up I-beam, with cap extrusions buck-riveted to the spar web. In the kit, the spar comes completely pre-assembled and finished (drilled and riveted, with flanged lightening holes). The rib stations on the spar are even pre-drilled – ready for final wing assembly. The structural aluminum wing ribs and fuselage bulkheads are supplied ready-to-install (pre-formed and finished at the factory with flanged lightening holes). The surface sheet-metal skins are blind riveted to the spar, ribs and bulkheads. Many flat surface skins are pre-drilled at the factory with a drilling machine, and are pre-formed and cut, ready for assembly.
The semi-monocoque rear fuselage requires the same type of simple assembly as the wings. The square rear fuselage is easily assembled by assembling each side on a flat workbench and then simply ‘boxing’ the four sides together. The forward fuselage (cabin) is made up of factory-riveted lower side frames, and and a welded 4130 chromium-molybdenum steel top frame. Fuselage and cabin parts are supplied ready for assembly as standard components of the complete kit.
The horizontal stabilizer tail is built up of two spars and internal ribs, covered with the pre-formed aluminum-alloy skin. The elevator is fabricated like the ailerons, and attached to the stabilizer with pins at each end. The pre-formed vertical tail skins cover the internal spar and ribs.
The standard fuel system is made up of dual welded-aluminum fuel tanks (10 US gallons each).
The STOL CH 701 is one of the few kits on the market that doesn’t just come with assembly instructions. The kit includes detailed blueprints of every part of the airframe, as well as a detailed assembly manual. In fact, the STOL CH 701 can be ‘scratch-built’ from the Drawings and Manuals, although this requires additional skills, time and tools.
Drawings and Manuals
Supplied with the complete STOL CH 701 kit, the drawings are not just assembly instructions (as with most kits), but are detailed 11″ x 17″ CAD blueprints of the entire airframe assembly and individual parts, and come with an assembly manual. The STOL CH 701 Drawings & Manuals package includes a CD-ROM with high-resolution Photo Assembly Guides for the step-by-step assembly of the STOL CH 701 kit.
Supplied with a serial number, you can actually build your own aircraft from “scratch” following the Drawings and Manuals. Scratch-builders can purchase any individual parts or components directly from Zenith Aircraft Company. If purchased separately, the cost of the drawings and manuals is deductible off the cost of the full kit.
Following are some selected sample CAD drawings from the STOL CH 701 drawings. These are sample drawings only and are for informational and educational purposes only.
|Sample Assembly Guide
|Rudder Tail Assembly: Skeleton Assembly: 1 of 2
|Horizontal Tail Assembly: Stabilizer: 1 of 2
|Horizontal Tail Assembly: Stabilizer: 2 of 2
|Horizontal Tail Assembly: Elevator: 1 of 2
|Horizontal Tail Assembly: Elevator: 2 of 2
|Wing Assembly 1 – Internal Structure
|Wing Assembly 2 – Internal Structure