Patents Assigned to Smiths PLC
  • Patent number: 4891971
    Abstract: Abnormal start conditions, such as hot starts or hung starts, in an aircraft gas-turbine engine are monitored by deriving signals indicative of spool speed, engine temperature and fuel flow. A processor receives these signals and derives an indication of the rate of change of engine temperature. Signals indicative of whether the aircraft is on the ground or in the air are derived from a air speed sensor or undercarriage pressure switch. The processor monitors the relationship between these signals to determine when the relationship between them is indicative of an abnormal start condition and indicates this on a display such as by flashing the display of engine temperature.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: January 9, 1990
    Assignee: Smiths PLC
    Inventors: John W. D. Jones, Peter F. O'Sullivan