A method of operating a marine vessel hybrid propulsion system having a propulsion shaft and a propeller, an internal combustion piston engine in force transmission connection with the propulsion shaft, and an electric motor-generator in force transmission connection with the propulsion shaft and/or with the piston engine. The internal combustion piston engine can be started by applying electric power from an on-board power source to the electric motor-generator and rotating the internal combustion piston engine by the electric motor-generator and rotational speed of the internal combustion piston engine is accelerated to a predetermined limit rotational speed without attempting to start the internal combustion piston engine, and only after the rotational speed of the internal combustion piston engine reaches the predetermined limit rotational speed, the internal combustion piston engine is started.

A method for operating a ship propulsion system. A setpoint rotational speed is determined for a propeller shaft and a setpoint pitch angle for an adjustable propeller on a control side based on an adjustable propeller characteristic diagram and an operator. An engine is determined based on a ship's engine characteristic diagram and the setpoint rotational speed for the propeller shaft. An actual engine operating point is determined as a function of a measured actual rotational speed and a measured actual torque, so that when the drive power is constant, the set-point rotational speed for the propeller shaft and the pitch angle for the adjustable propeller can be varied while reducing fuel consumption of the ship's engine and, when this is possible, the setpoint rotational speed for the propeller shaft, the setpoint pitch angle for the adjustable propeller and the setpoint operating point of the ship's engine are adapted.

A method for operating a ship propulsion system. A setpoint rotational speed is determined for a propeller shaft and a setpoint pitch angle for an adjustable propeller on a control side based on an adjustable propeller characteristic diagram and an operator. An engine is determined based on a ship's engine characteristic diagram and the setpoint rotational speed for the propeller shaft. An actual engine operating point is determined as a function of a measured actual rotational speed and a measured actual torque, so that when the drive power is constant, the set-point rotational speed for the propeller shaft and the pitch angle for the adjustable propeller can be varied while reducing fuel consumption of the ship's engine and, when this is possible, the setpoint rotational speed for the propeller shaft, the setpoint pitch angle for the adjustable propeller and the setpoint operating point of the ship's engine are adapted.

An electronic control system (30) for a turbopropeller engine (1) having a gas turbine (2, 4, 5, 6) and a propeller (7), coupled to the gas turbine, the control system (10) having a propeller control unit (14) and a turbine control unit (15) to jointly control engine power output based on an input request (PLA), wherein the propeller control unit (14) has a first reference generator (16), to determine a reference propeller speed (N.sub.pref) based on the input request (PLA), and a first regulator (19), to regulate a propeller speed (N.sub.p). The propeller control unit (14) has a reference correction stage (31) to apply a correction to the reference propeller speed (N.sub.pref) and generate thereby a corrected reference propeller speed (I), and the first regulator (19) regulates the propeller speed (N.sub.p) based on the corrected reference propeller speed (I) to achieve optimized efficiency.

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

A method of designing a turbofan engine according to an exemplary aspect of the present disclosure includes, among other things, providing a fan section including a plurality of fan blades, providing a low pressure turbine driving the plurality of fan blades through a gear train, providing a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, providing a fan bypass flow path defined between the core nacelle and the fan nacelle, and providing a fan variable area nozzle in communication with the fan bypass flow path and defining a fan nozzle exit area between the fan nacelle and the core nacelle.

A recreational vehicle includes a seatbelt sensor configured to detect when a seatbelt is in an engaged position or a disengaged position and an engine control module in communication with the seatbelt sensor to automatically limit a maximum speed of the vehicle to a reduced maximum speed limit upon detection of the seatbelt is in the disengaged position.

A recreational vehicle includes a seatbelt sensor configured to detect when a seatbelt is in an engaged position or a disengaged position and an engine control module in communication with the seatbelt sensor to automatically limit a maximum speed of the vehicle to a reduced maximum speed limit upon detection of the seatbelt is in the disengaged position.

A method for operating a ship propulsion system. A setpoint rotational speed is determined for a propeller shaft and a setpoint pitch angle for an adjustable propeller on a control side based on an adjustable propeller characteristic diagram and an operator. An engine is determined based on a ship's engine characteristic diagram and the setpoint rotational speed for the propeller shaft. An actual engine operating point is determined as a function of a measured actual rotational speed and a measured actual torque, so that when the drive power is constant, the set-point rotational speed for the propeller shaft and the pitch angle for the adjustable propeller can be varied while reducing fuel consumption of the ship's engine and, when this is possible, the setpoint rotational speed for the propeller shaft, the setpoint pitch angle for the adjustable propeller and the setpoint operating point of the ship's engine are adapted.

A recreational vehicle includes a seatbelt sensor configured to detect when a seatbelt is in an engaged position or a disengaged position and an engine control module in communication with the seatbelt sensor to automatically limit a maximum speed of the vehicle to a reduced maximum speed limit upon detection of the seatbelt is in the disengaged position.