The delivery, just eight days after the order had been placed with RotorWay International in Arizona, caught Harms with his hangar incomplete. His wife signed off on the project on the condition that he not build it after hours at his auto-body shop—she had the wifely intuition that she might not see him for months of Sundays. One big crate stores dozens of lumpy, shrink-wrapped cardboard sheets.
This is how RotorWay packages smaller parts like snap rings, pins, nuts, and bolts, which if shipped en masse in plastic bags could wind up in the wrong holes. When all checks are done and forms completed, the customer finds that he or she is the manufacturer of a new aircraft, as well as its mechanic, notwithstanding the lack of an airframe-and-powerplant license. This has its pros and cons. On one hand, the sellers of such kits can be agile and adaptive, which helps keep production costs low.
They can choose to ship whatever engine suits their fancy, or can leave the choice to the buyer, who could use a rotary engine from a Mazda RX-7 if he could adapt the power train. Since the FAA does not certify unassembled kit helicopter models as airworthy, it offers no opinion on such matters. It helps to start with a well-equipped workshop, a methodical style, and a familiarity with engines. But speed is not the point.
Think of a big watch: The pod and boom fuselage has a glass fibre cabin built on a steel tube frame, with a long transparent forward opening canopy. The steel frame also carries the engine, semi-exposed behind the accommodation and connected to the main rotor shaft by a belt drive. A slender aluminium boom, strengthened by a pair of long struts to the lower fuselage frame, carries both the tail rotor and swept fins. The upper fin is topped with a short horizontal tailplane, with small endplate fins, and the lower one ends with a tailskid.
The CH-7 uses a simple aluminium skid undercarriage, which may be fitted with small wheels for ground handling or multi-tube inflatable floats for flying off water. In this last form the CH-7 is called the Mariner. The Kompress Charlie has faired, wide chord carbon fibre skid legs. A fast build kit, with more components pre-assembled, is claimed to need 85 hours. The Mosquito frame is made up of Aircraft Grade T6 aluminum and utilities a simple triangulated structure with straight tubing throughout to maximize strength, reduce weight and simplify construction.
Ground handling wheels are also available to easy ground transport. This engine employes Reed Induction which yields a very flat torque curve ensuring power is delivered constantly over the required operating range. The MZ also has a lower operating speed of rpm when compared to other engines with similar power range that typically operate at to rpm resulting in less stress on the engine and improving reliability.
The complete engine package only weighs 69 pounds and comes with a watt alternator that provides power to run the electrical system which also features and an electric start system. The primary reduction is bolted directly to the engine. A centrifugal clutch on the engine crankshaft permits start up of the engine without the load of the rotor. Power is transmitted from the clutch to the driven pulley of the reduction through an HTD cog belt, one of the highest power to weight ratio power transmission methods available.
The driven pulley houses the sprage clutch which permits the rotor to over speed the engine during auto-rotation. Gallons per hour Flight Duration Time: Compact Radial Engines MZ, 2 cylinder, 2 stroke, rated 60 HP 45kW Electrical System: Main rpm, Tail rpm Performance: Hover in ground effect: