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 taxi tug includes a chassis, a motive power source, and an auxiliary power services system. The chassis has at least one drive wheel. The motive power source is operatively connected to the at least one drive wheel. The auxiliary power services system is disposed on the chassis and is configured to provide at least one of electric power, pneumatic power, and low pressure conditioned air to an aircraft.

A taxi tug includes a chassis, a motive power source, and an auxiliary power services system. The chassis has at least one drive wheel. The motive power source is operatively connected to the at least one drive wheel. The auxiliary power services system is disposed on the chassis and is configured to provide at least one of electric power, pneumatic power, and low pressure conditioned air to an aircraft.

An aircraft ground support unit (1) (GSU) for supplying a specific service according to a specific set of service parameters to an aircraft (2) on the ground and consuming a specific service energy is provided that includes: a rechargeable energy storage unit (3) (RESU) for autonomously delivering the specific service energy required for supplying the specific service in the given available service duration; an energy sensor (4) for measuring an instantaneous state of energy parameters of the RESU; and a control unit. The RESU, identifying the aircraft (2), identifying in a database the specific set of service parameters for identified aircraft, establishing a specific service energy budget estimate, determining an instantaneous charge level of the RESU, comparing the specific service energy budget estimate with the instantaneous charge level of the RESU, and generating an output signal representative of a capacity of the RESU to deliver the specific service energy budget estimate as a function of the instantancous charge level.

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 (f.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 (f.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 flexible electric cable for the electric power supply of planes on the ground is subjected to an unspooling and spooling process, the cable having a conductor layout including a plurality of insulated energy supply conductors which are arranged concentrically with respect to a longitudinal central axis of the generally circular in cross-section cable, several insulated neutral conductors which are arranged concentrically with respect to the central axis, and several insulated control conductors which are arranged concentrically with respect to the central axis. A non-metallic, tension-and compression-resistant support member is disposed at the center of the cable, which support member extends over the length of the cable. At least the energy supply conductors include CCA wires having a copper content of at least 15%.

A flexible electric cable for the electric power supply of planes on the ground is subjected to an unspooling and spooling process, the cable having a conductor layout including a plurality of insulated energy supply conductors which are arranged concentrically with respect to a longitudinal central axis of the generally circular in cross-section cable, several insulated neutral conductors which are arranged concentrically with respect to the central axis, and several insulated control conductors which are arranged concentrically with respect to the central axis. A non-metallic, tension-and compression-resistant support member is disposed at the center of the cable, which support member extends over the length of the cable. At least the energy supply conductors include CCA wires having a copper content of at least 15%.

An aircraft ground support unit (1) for supplying a service to an aircraft (3) on the ground according to a specific servicing program is provided that includes reception means (5) suitable for identifying an aircraft (3) in motion or parked on the ground by receiving information emitted by a transponder (7) of said aircraft including an instantaneous GPS coordinates of the position of the aircraft, the identity of the aircraft, the type of aircraft, and the company of the aircraft, aircraft status data. A microprocessor is provided that is suitable for selecting and implementing a predefined servicing program stored in a database corresponding to the type and company of the thus identified aircraft (3) on the basis of the information received by the reception means. A data record device is also provided that is to store the events, aircraft status data, ground unit data for airlines operation optimization.

A power electronics module is provided having one or more power converter semiconductor components. The power electronics module further has a substrate having a first surface to which the one or more components are mounted, and having an opposing second surface from which project a plurality of heat transfer formations for enhancing heat transfer from the substrate. The power electronics module further has a coolant housing which sealingly connects to the substrate to form a void over the heat transfer formations of the second surface. The coolant housing has an inlet for directing a flow of an electrically insulating coolant into the void and an outlet for removing the coolant flow from the void, whereby heat generated during operation of the one or more components is transferred into the coolant flow via the substrate.