Patent ID: 6881948

Claim:
In an aircraft including a hot engine bleed air system with a bleed air pipe, a temperature sensor arranged proximate to said bleed air pipe, and a monitoring arrangement that includes a computer and that is connected to said temperature sensor so as to receive and evaluate signals therefrom, an improvement wherein: said temperature sensor comprises a fiber optic cable that is arranged to extend along said bleed air pipe and that includes plural sensor zones along said fiber optic cable; said monitoring arrangement further includes a laser emitter connected to said computer to be controlled by said computer, and an optical receiver connected to said computer to provide a receiver signal thereto; said laser emitter is further connected to a first end of said fiber optic cable so as to transmit a laser input pulse from said laser emitter into said fiber optic cable; said optical receiver is further connected to said first end of said fiber optic cable so that said optical receiver receives from said fiber optic cable a reflection signal including a temperature-dependent reflection pulse that arises from at least one reflection of said input pulse in said fiber optic cable; said reflection signal exhibits an amplitude and a reflection transit time of said temperature-dependent reflection pulse; said optical receiver produces said receiver signal in response to and dependent on said reflection signal so that said receiver signal represents said amplitude and said reflection transit time; said computer is adapted and programmed to allocate respective different transit time ranges individually to said plural sensors zones, and to allocate respective different amplitude limits representing different temperature limits individually to said plural sensor zones; and said computer is further adapted and programmed to evaluate said receiver signal so as to determine a location of a bleed air leak from said bleed air pipe as falling into a particular one of said plural sensor zones by determining into which one of said transit time ranges said reflection transit time falls; and said computer is further adapted and programmed to evaluate said receiver signal so as to determine an existence of said bleed air leak by comparing said amplitude to a particular one of said amplitude limits that is allocated to said particular one of said sensor zones.