An unmanned aerial vehicle capable of VTOL operation can include: a vehicle body defining longitudinal and transverse directions and opposing longitudinal sides; a first support boom coupled to the vehicle body at a first transverse axis and extending outwardly from the opposing longitudinal sides; a second support boom coupled to the vehicle body at a second transverse axis positioned rearward from the first transverse axis and extending outwardly from the opposing longitudinal sides; a plurality of electric motors coupled to a one of the first and second support booms, at least two electric motors of the plurality of electric motors positioned on each of the first and second support booms, a rotation axis of each of the at least two electric motors coupled to the second support boom offset in a transverse direction from a rotation axis of each of the at least two adjacent electric motors coupled to the first support boom; a plurality of rotors; and a propulsion system.

An unmanned aerial vehicle capable of VTOL operation can include: a vehicle body defining longitudinal and transverse directions and opposing longitudinal sides; a first support boom coupled to the vehicle body at a first transverse axis and extending outwardly from the opposing longitudinal sides; a second support boom coupled to the vehicle body at a second transverse axis positioned rearward from the first transverse axis and extending outwardly from the opposing longitudinal sides; a plurality of electric motors coupled to a one of the first and second support booms, at least two electric motors of the plurality of electric motors positioned on each of the first and second support booms, a rotation axis of each of the at least two electric motors coupled to the second support boom offset in a transverse direction from a rotation axis of each of the at least two adjacent electric motors coupled to the first support boom; a plurality of rotors; and a propulsion system.

An aircraft propeller drive system has a gear to be driven by an engine and having a first plurality of teeth. A torsion bar has a first end driven by the gear and a second end rotatable relative to the first end about a torsion axis by a torsion angle. An output shaft is driven by the second end and is adapted for connection to a propeller. A clutch has a driven member rotationally fixed to the output shaft and a driving member having a second plurality of teeth. The first and second pluralities of teeth engage each other when a variation in the torsion angle from a mean torsion angle is greater than a predetermined angle. Torque is transferred between the gear and the output shaft via the clutch when the first and second pluralities of teeth engage each other.

An aircraft propeller drive system has a gear to be driven by an engine and having a first plurality of teeth. A torsion bar has a first end driven by the gear and a second end rotatable relative to the first end about a torsion axis by a torsion angle. An output shaft is driven by the second end and is adapted for connection to a propeller. A clutch has a driven member rotationally fixed to the output shaft and a driving member having a second plurality of teeth. The first and second pluralities of teeth engage each other when a variation in the torsion angle from a mean torsion angle is greater than a predetermined angle. Torque is transferred between the gear and the output shaft via the clutch when the first and second pluralities of teeth engage each other.

An autonomous unmanned aerial vehicle for land, sea and air use. The autonomous unmanned aerial vehicle is more specifically related to an unmanned aerial vehicle, wherein the autonomous unmanned aerial vehicle is configured to vertically take off and vertically land, fly with fixed wings and stay in the air silently for a long time by means of a balloon inflated behind it.

An autonomous unmanned aerial vehicle for land, sea and air use. The autonomous unmanned aerial vehicle is more specifically related to an unmanned aerial vehicle, wherein the autonomous unmanned aerial vehicle is configured to vertically take off and vertically land, fly with fixed wings and stay in the air silently for a long time by means of a balloon inflated behind it.

An internal combustion engine for an aircraft can include a crankshaft configured to drive a propeller; a camshaft coupled to the crankshaft; and an ignition controller coupled to the camshaft and including a visual indicator, the visual indicator configured to produce a visual signal at a predetermined angular position of the engine. An ignition controller for an internal combustion engine can include a housing and a P-lead connection extending from the housing, the ignition controller configured to selectively supply or cut main electrical power from the engine via the P-lead connection, the ignition controller also configured to selectively supply its own power.

An internal combustion engine for an aircraft can include a crankshaft configured to drive a propeller; a camshaft coupled to the crankshaft; and an ignition controller coupled to the camshaft and including a visual indicator, the visual indicator configured to produce a visual signal at a predetermined angular position of the engine. An ignition controller for an internal combustion engine can include a housing and a P-lead connection extending from the housing, the ignition controller configured to selectively supply or cut main electrical power from the engine via the P-lead connection, the ignition controller also configured to selectively supply its own power.

An internal combustion engine for an aircraft can include a crankshaft configured to drive a propeller; a camshaft coupled to the crankshaft; and an ignition controller coupled to the camshaft and including a visual indicator, the visual indicator configured to produce a visual signal at a predetermined angular position of the engine. An ignition controller for an internal combustion engine can include a housing and a P-lead connection extending from the housing, the ignition controller configured to selectively supply or cut main electrical power from the engine via the P-lead connection, the ignition controller also configured to selectively supply its own power.

An internal combustion engine for an aircraft can include a crankshaft configured to drive a propeller; a camshaft coupled to the crankshaft; and an ignition controller coupled to the camshaft and including a visual indicator, the visual indicator configured to produce a visual signal at a predetermined angular position of the engine. An ignition controller for an internal combustion engine can include a housing and a P-lead connection extending from the housing, the ignition controller configured to selectively supply or cut main electrical power from the engine via the P-lead connection, the ignition controller also configured to selectively supply its own power.