Ultralight Aircraft

Overview

An ultralight aircraft is the lightest category of powered fixed-wing flight, built to carry one pilot on short recreational flights at low cost. This single-seat design pairs a strut-braced high wing with a welded steel-tube fuselage and a fabric or thin-aluminium skin, keeping empty weight near 254 kg so the aircraft stays inside the regulatory limits that allow it to fly without a full type certificate.

The structure is organised around a load-carrying Airframe that bolts together a tube-and-fabric fuselage, two wings and the tail. The pilot flies it through a simple mechanical Flight Control System of cables and pushrods. Thrust comes from a Rotax four-stroke Rotax Four-Stroke Engine turning a composite Propeller, and the aircraft sits on fixed tricycle Landing Gear. The pilot works from an open Cockpit behind a formed Windscreen.

How it works

Lift is generated by the high wing, whose airfoil is held by an aluminium spar and stamped ribs and braced to the lower fuselage by a streamlined strut. The pilot commands roll, pitch and yaw through the control stick and rudder pedals; these move the ailerons, elevator and rudder by way of steel cables and rigid pushrods, with no hydraulic boost.

Power comes from the Rotax Four-Stroke Engine, a liquid-cooled flat-twin that drives the propeller through a reduction gearbox so the blades turn slower than the crankshaft for better efficiency and lower noise. Fuel is fed by gravity and a pump from the wing-root tank to twin carburetors, and a dual ignition system fires the spark plugs. The engine also turns the alternator inside the Electrical System system, which charges the battery and runs the radios and the EFIS glass display in the Cockpit. On landing the sprung gear legs absorb the touchdown and disc brakes on the main wheels slow the rollout.