Patent ID: 7496433

Claim:
A method of minimizing the noise emitted during take-off and landing of a rotorcraft ( 1 ) of a particular type of rotorcraft, the method being characterized in that in a preliminary flight period, in which a reference rotorcraft corresponding to a rotorcraft ( 1 ) of said particular type is used, the following steps are performed: a) taking a series of measurements on the reference rotorcraft, to obtain during preliminary flights, values for a plurality of noise levels detected by a plurality p of sensors C secured to the reference rotorcraft and representative of noise emission for n configurations of the reference rotorcraft, determined by: m masses M of said reference rotorcraft; q speeds of rotation R 1 for the main rotor ( 3 ); and r speeds of rotation R 2 for the tail rotor ( 4 ); b) from said series of measurements, establishing a first series of n×p diagrams D 1 representing a series of equal noise levels L 1 in a system of coordinates (TA, VZA), where TA is the flight path air-speed and VZA is the vertical air-speed of said reference rotorcraft; c) transforming said first series of diagrams D 1 into a second series of n×p diagrams D 2 representing a series of equal noise levels L 2 in the system of coordinates (TA, VZA) by: firstly making a noise correction CV representative of noise nuisance depending on the duration of noise application; and secondly making a correction CMA to correcting each mass M into an apparent weight MA of the reference rotorcraft as a result of atmospheric conditions at flying altitude; d) selecting in each diagram D 2 the curve of equal noise levels L 2 P corresponding to a maximum acceptable noise BMA; e) for each apparent weight MA, establishing the envelope of the curves L 2 P in the system of coordinates (TA, VZA) so as to determine m flight domains DV for which noise is less than said maximum acceptable noise BMA; and f) selecting in each flight domain DV, an operating domain DF which determines a set of m operating domains of the reference rotorcraft.