Patent ID: 8121773
Filing Date: 2012-02-21
Classification: F02C,F05D,G01D

Abstract:
1. A method for a rotorcraft provided with a turboshaft engine having a surveillance parameter, wherein the surveillance parameter has a guaranteed minimum value at a given engine operating condition when the engine is old, the method comprising: a) during a preliminary stage, operating the engine at the given engine operating condition, monitoring the engine to obtain a current value of the surveillance parameter, and determining a preliminary comfort margin from a real difference equal to said current value during the preliminary stage minus said guaranteed value; and b) during a main stage, operating the engine and monitoring the engine to obtain a current value of the surveillance parameter, wherein the surveillance parameter has a limit value depending on the operation of the engine; and b1) determining a useful comfort margin from said preliminary comfort margin; b2) determining an apparent difference equal to the difference between the current value during the main stage and the limit value of said surveillance parameter; and b3) determining a limiting margin as being equal to the useful comfort margin subtracted from the apparent difference.