Disclosed are systems and methods for testing aircraft engine that are not currently associated with a functional aircraft or systems. For testing, systems on the engine being tested are connected with the reciprocating systems (e.g., engine electronic controls, main and motive fuel) on a fully functional aircraft using conduits that have been extended to lengths enabling the connection.

Systems and methods for starting a powerplant are provided. In one exemplary aspect, a starting system of a powerplant includes one or more features that allow for the powerplant to be started electrically with a burst of electrical power and without deriving electrical power from an offboard power source or a relatively heavy onboard energy storage device.

Systems and methods for starting a powerplant are provided. In one exemplary aspect, a starting system of a powerplant includes one or more features that allow for the powerplant to be started electrically with a burst of electrical power and without deriving electrical power from an offboard power source or a relatively heavy onboard energy storage device.

A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed, where the controller modulates a duty cycle of the discrete starter valve via pulse width modulation.

A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed, where the controller modulates a duty cycle of the discrete starter valve via pulse width modulation.

Various embodiments of the present disclosure provide a parasail-assisted system for launching a fixed-wing aircraft into free flight and for retrieving a fixed-wing aircraft from free flight.

Various embodiments of the present disclosure provide a parasail-assisted system for launching a fixed-wing aircraft into free flight and for retrieving a fixed-wing aircraft from free flight.

A system for controlling a start sequence of a gas turbine engine includes an electronic engine control system, a thermal model, memory, a model for determining a time period (t.sub.motoring), and a controller. The thermal model synthesizes a heat state of the gas turbine engine. The memory records the current heat state at shutdown and a shutdown time of the gas turbine engine. The model for determining the time period is for motoring the gas turbine engine at a predetermined speed N.sub.target that is less than a speed to start the gas turbine engine, where t.sub.motoring is a function of the heat state recorded at engine shutdown and an elapsed time of an engine start request relative to a previous shutdown time. The controller modulates a starter valve to maintain the gas turbine engine within a predetermined speed range of N.sub.targetMin to N.sub.targetMax for homogenizing engine temperatures.

A system for controlling a start sequence of a gas turbine engine includes an electronic engine control system, a thermal model, memory, a model for determining a time period (t.sub.motoring), and a controller. The thermal model synthesizes a heat state of the gas turbine engine. The memory records the current heat state at shutdown and a shutdown time of the gas turbine engine. The model for determining the time period is for motoring the gas turbine engine at a predetermined speed N.sub.target that is less than a speed to start the gas turbine engine, where t.sub.motoring is a function of the heat state recorded at engine shutdown and an elapsed time of an engine start request relative to a previous shutdown time. The controller modulates a starter valve to maintain the gas turbine engine within a predetermined speed range of N.sub.targetMin to N.sub.targetMax for homogenizing engine temperatures.

A ground support system (1) for an aircraft having a turbine engine, which ground support system comprises; an intermittent combustion engine (2), a generator (3) which is driven by the combustion engine to supply electrical power with a constant frequency, an electricity cable (4) to transport the electrical power to the aircraft, an air pump (5) which is driven by the combustion engine to supply pressurised air, an air duct (6) to transport the pressurised air to the aircraft, a control unit (7) to control the operation of the ground support system (1), which control unit (7) communicates with the combustion engine (2) to let the combustion engine run at a predetermined engine rotational speed, and wherein the air pump (5) is driven by the combustion engine (2) via an adjustable transmission (16) to adjust an air flow rate of the pressurised air supplied by the air pump (5), while the combustion engine (2) remains running at the predetermined engine rotational speed.