Patent ID: 9739207
Date: 2017-08-22
CPC Classifications: B64D,F02C,F02K,F05D,Y02T

Claim:
1. A method of controlling one or more gas turbine engine of an aircraft, the method comprising: sensing a condition indicative of vapour trail formation by an exhaust flow from the engine using one or more sensor; controlling actuation of a flow opening for a propulsive fan of the engine so as to reduce an efficiency of the engine upon sensing of a condition by the one or more sensor; altering, by a controller, one or more further operational variable of the engine in order to maintain a desired level of thrust whilst the engine efficiency is reduced; determining, by the controller, a maximum available change to the further operational variable under current operating conditions and a corresponding minimum engine efficiency achievable; and reducing, by the controller, engine efficiency only if the minimum engine efficiency is determined to prevent contrail formation.