Abstract: A tail rotor system for a helicopter includes a gear box housing retainer (66) coupled to the tail boom (16) of the helicopter. The tail rotor system also includes a power-limiting device (50) configured to disconnect the tail rotor from a power plant for driving the tail rotor about a rotor axis of rotation.

Abstract: A hand-held starter apparatus for starting model engines includes a motor, a body supporting the motor, a switching device that activates the motor, and a trigger in communication with the switching device. The body is configured for comfortable gripping by users with large hands and by users with small hands.

Abstract: A hand-held starter apparatus for starting model engines includes a motor, a body supporting the motor, a switching device that activates the motor, and a trigger in communication with the switching device. The body is configured for comfortable gripping by users with large hands and by users with small hands.

Abstract: A glow plug (10, 150, 170, 190, 250) is provided for use in a model engine 12 and for connecting to a glow plug clip (30). The glow plug (10, 150, 170, 190, 250) includes a coil (38) having spaced apart first and second ends (42, 44), a first conductor (34) coupled to the first end (42) of the coil (38), and a second conductor (40) coupled to the second end (44) of the coil (38). The second conductor (40) includes a body and a glow plug clip-retaining portion (32, 152, 172, 192, 252) and the glow plug clip-retaining portion is defined by an indentation (70, 72, 176, 196, 256) in the body.

Abstract: A landing gear assembly is provided for use on a model helicopter. The landing gear assembly includes a landing gear strut having a leg portion and a foot portion connected to the leg portion to define an included right angle therebetween. The assembly also includes a landing gear skid formed to include a landing gear strut attachment area provided with an L-shaped slot arranged to receive and trap the foot portion of the landing gear strut therein.

Abstract: An exhaust control mechanism is provided for use in a model engine system having a source of engine exhaust. The exhaust control mechanism includes first and second tubes and a valve movable in one of the first and second tubes. The first tube includes an upper portion, a lower portion, and a first passage extending through the upper portion and lower portion. The upper portion of the first tube is adapted to couple to a source of engine exhaust. The second tube is coupled to the first tube and the second tube is formed to include a second passage that intersects the first passage formed in the first tube at an intersection region. The valve is movable in one of the first and second tubes to extend into the intersection region.

Abstract: A swashplate is provided for use in helicopters having a vertical main rotor axis. The swashplate includes a bearing, a first race member including a channel, a second race member including a channel, and a third race member including a channel. The channels of the first, second, and third race members cooperate to form a bearing-receiving slot. The bearing is positioned to lie in the bearing-receiving slot. The first and second race members are adjustably coupled to change the respective positions of their channels.

Abstract: A main rotor is provided for use on a model helicopter. The main rotor includes rotor blades having an inboard section and an outboard section. The inboard section includes a higher camber, thin, wide airfoils, and greater pitch and camber relative to the outboard section. The outboard section includes an average chord length that is less than the chord length of the inboard section, The rotor blades also include a blade body that is semiflexible to bend during a crash landing of the model helicopter.

Abstract: A model rotary wing aircraft is provided that includes a fuselage, a power plant, a main rotor, a tail rotor, and a drive apparatus. The power plant includes a passive cooling system to transfer heat produced by the power plant to the atmosphere. The passive cooling system consumes less than about five percent of the power produced by the power plant. The main rotor is driven by the power plant at a main rotor speed of rotation and the tail rotor is driven by the power plant at a tail rotor speed of rotation. The drive apparatus transfers power from the power plant to the main rotor and tail rotor to rotate the tail rotor at a tail rotor speed of rotation that is about three times greater than the main rotor speed of rotation to minimize the amount of power used by the tail rotor.

Abstract: In a helicopter having a device for stabilizing yaw motion through the use of a tail rotor with a plurality of rotor blades extending radially from a hollow rotor shaft which is mounted for rotation about a transverse rotor axis. The tail rotor is provided with a device for varying the thrust by a pilot input to the blades of the tail rotor and through the use of a gyro rotor for automatic control of the tail rotor. The invention further comprises a three point mixing linkage that permits the control of the tail rotor through both the pilot inputs and the gyro rotor inputs.

Abstract: A main rotor is provided for use in a rotary winged model aircraft. The main rotor includes a rotor hub assembly rotatable about a vertical axis and at least two main rotor blades. Each of the main rotor blades extends in a radial direction from the rotor hub assembly. The main rotor blades each include a tip end positioned to lie in spaced-apart relation to the rotor hub assembly and a root end coupled to the rotor hub assembly for pivotable folding movement from an initial horizontal position perpendicular to the vertical axis about a horizontal axis through a desired folding angle of about 90.degree.. Forces transmitted to the rotor hub by the rotor blade during a crash-landing of a rotary winged model aircraft including the main rotor are minimized due to movement of the rotor blades through the desired folding angle.

Abstract: A fuselage structure for use on a model helicopter includes a longitudinally extending keel defined by a vertical flat plate oriented to lie in parallel relation to a longitudinal axis of the model helicopter. A radio control system component is mounted to the vertical flat plate. The fuselage structure also includes a laterally extending floor perpendicular to the keel, a front bulkhead appended to the keel and a forward end of the floor, and a firewall appended to the keel and a rearward end of the floor. A landing gear assembly is coupled to the fuselage structure at a junction positioned to lie adjacent to a forward portion of a bottom edge of the keel.

Abstract: A device for stabilizing yaw motion is provided for use on a helicopter having a main rotor rotatable about a main rotor axis, a power source, and a tail rotor boom with a longitudinal axis. The device includes a tail rotor and a gyroscopic mechanism. The tail rotor is mounted to the tail boom of a helicopter and is rotated about a tail rotor axis by the power source to generate a thrust force transverse to the tail boom and offset from the main rotor axis. The gyroscopic mechanism automatically varies the thrust force generated by the tail rotor to oppose yaw motions. The gyroscopic mechanism includes first and second variable pitch gyro arms extending along first and second gyro arm pitch axes, respectively, a support mechanism, and a pitch adjustor linkage.

Abstract: In a helicopter having a tail rotor with a plurality of rotor blades extending radially from a hollow rotor shaft which is mounted for rotation about a transverse rotor axis, and having a push-pull rod extending through the hollow shaft and operably connected to the blades to manually vary the collective pitch of the blades, a device for automatically stabilizing the yaw motion of the helicopter includes a gyroscopic assembly having a gyro rotor mounted to rotate with the tail rotor, to pivot about a substantially longitudinal pivot axis by and at the outboard end of the push-pull rod and to automatically vary the collective pitch of the blades in response to yaw motion.