A method of performing a health check of at least one turbine engine (3). During a development step (STP0), the installation losses (1) are quantified for a plurality of test values for a reduced speed of rotation (Ng′) of a gas generator (4) of the engine. During an acquisition step (STP1), the speed of rotation of said gas generator (4) is increased until said engine develops a maximum power, and then the speed of rotation of the gas generator (4) is decreased until the reduced speed of rotation (Ng′) reaches a test value. The aircraft is stabilized and at least one monitoring value is acquired. During an evaluation step (STP2) of evaluating the health check, at least one operating margin is determined by using a monitoring value and the effects of mounting the engine in an airplane.