×

Modified start sequence of a gas turbine engine

  • US 10,040,577 B2
  • Filed: 02/12/2016
  • Issued: 08/07/2018
  • Est. Priority Date: 02/12/2016
  • Status: Active Grant
First Claim
Patent Images

1. A system for starting a gas turbine engine of an aircraft, the system comprising:

  • a pneumatic starter motor;

    a discrete starter valve switchable between an on-state and an off-state;

    a controller operable to perform a starting sequence for the gas turbine engine, the starting sequence comprising 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;

    an electronic engine control system comprising;

    a memory for recording a current heat state of the gas turbine engine at shutdown and for recording a shutdown time of the gas turbine engine; and

    a risk model for determining a time period (tmotoring) for motoring the gas turbine engine at a predetermined speed Ntarget wherein the predetermined speed is less than a speed used to start the gas turbine engine and wherein tmotoring is a function of the heat state recorded at engine shutdown and an elapsed time of an engine start request relative to the previous shutdown time.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×