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Motor glider
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Motor glider
A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing aerodyne equipped with a means of propulsion (MoP), capable of sustained soaring flight without thrust from the means of propulsion.
In 1935, an occasional or auxiliary motor that could be retracted was suggested by Sir John Carden. This was incorporated into the Carden-Baynes Auxiliary that first flew on 8 August of the same year. A later version of the Budig glider was powered.
Most motor gliders are equipped with a propeller, which may be fixed, feathered (e.g. AMS-Flight Carat), or retractable. However jet engine-powered motorgliders are now available from some manufacturers, some of which are intended for use only as "sustainer" engines, i.e. for sustaining gliding flight rather than as self-launching aircraft.
Sustainer motor gliders must be launched like an unpowered glider, but can climb slowly to extend a flight once the engine is deployed and started. They generally do not have an alternator or starter motor, so the engine is started by "wind-milling" the propeller in flight. The propeller may be a rigid 2-blade design, or may have more than two blades that fold at the hub when the engine is retracted. The propeller hub is usually attached directly to the crankshaft, but there is at least one example of a sustainer with a belt reduction drive, the DG-1000T.
The smaller sustainer engines are usually not equipped with a throttle, but instead have a cable to open decompression valves in each cylinder to allow the engine to turn freely for starting. Sustainer engines are typically two-stroke two-cylinder air-cooled engines in the range of 18–30 hp (14–22 kW). They are lighter in weight, and simpler to operate than self-launching powerplants.
Self-launching retractable propeller motor gliders have sufficient thrust and initial climb rate to take off without assistance, or they may be launched as with a conventional glider. The engines also have a starter motor and a large battery to allow the engine to be started on the ground, and an alternator to recharge the battery. A two-blade propeller is typically coupled to the engine via a belt reduction drive. In older designs, the propeller alignment must be checked by the pilot using a mirror, before it is retracted into the fuselage; however in current production gliders, propeller alignment is fully automatic.
Another solution is the single-blade propeller that offers the advantage of a smaller opening in the fuselage to retract the engine.
Internal combustion engines can benefit from mounting in the fuselage, rather than on the propeller mast. This allows them to be connected to a larger muffler for reduced noise when operating, something which is mostly relevant to European operation. It also allows the belt tension to be relieved when the engine is retracted to extend the life of the belt and bearings. The drawback of this arrangement is that engines fixed low in fuselages are more difficult to pre-flight and service, and highly stressed power transmission belts should not be bent or twisted.
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Motor glider AI simulator
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Motor glider
A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing aerodyne equipped with a means of propulsion (MoP), capable of sustained soaring flight without thrust from the means of propulsion.
In 1935, an occasional or auxiliary motor that could be retracted was suggested by Sir John Carden. This was incorporated into the Carden-Baynes Auxiliary that first flew on 8 August of the same year. A later version of the Budig glider was powered.
Most motor gliders are equipped with a propeller, which may be fixed, feathered (e.g. AMS-Flight Carat), or retractable. However jet engine-powered motorgliders are now available from some manufacturers, some of which are intended for use only as "sustainer" engines, i.e. for sustaining gliding flight rather than as self-launching aircraft.
Sustainer motor gliders must be launched like an unpowered glider, but can climb slowly to extend a flight once the engine is deployed and started. They generally do not have an alternator or starter motor, so the engine is started by "wind-milling" the propeller in flight. The propeller may be a rigid 2-blade design, or may have more than two blades that fold at the hub when the engine is retracted. The propeller hub is usually attached directly to the crankshaft, but there is at least one example of a sustainer with a belt reduction drive, the DG-1000T.
The smaller sustainer engines are usually not equipped with a throttle, but instead have a cable to open decompression valves in each cylinder to allow the engine to turn freely for starting. Sustainer engines are typically two-stroke two-cylinder air-cooled engines in the range of 18–30 hp (14–22 kW). They are lighter in weight, and simpler to operate than self-launching powerplants.
Self-launching retractable propeller motor gliders have sufficient thrust and initial climb rate to take off without assistance, or they may be launched as with a conventional glider. The engines also have a starter motor and a large battery to allow the engine to be started on the ground, and an alternator to recharge the battery. A two-blade propeller is typically coupled to the engine via a belt reduction drive. In older designs, the propeller alignment must be checked by the pilot using a mirror, before it is retracted into the fuselage; however in current production gliders, propeller alignment is fully automatic.
Another solution is the single-blade propeller that offers the advantage of a smaller opening in the fuselage to retract the engine.
Internal combustion engines can benefit from mounting in the fuselage, rather than on the propeller mast. This allows them to be connected to a larger muffler for reduced noise when operating, something which is mostly relevant to European operation. It also allows the belt tension to be relieved when the engine is retracted to extend the life of the belt and bearings. The drawback of this arrangement is that engines fixed low in fuselages are more difficult to pre-flight and service, and highly stressed power transmission belts should not be bent or twisted.