초록 ▼

The invention relates to a method of piloting a rotorcraft having a plurality of engines for driving at least one lift and propulsion rotor, in which method, so long as the rotorcraft has not reached an optimum climb speed (OCS), a pitch attitude control signal (Upitch) is determined that is adapted

The invention relates to a method of piloting a rotorcraft having a plurality of engines for driving at least one lift and propulsion rotor, in which method, so long as the rotorcraft has not reached an optimum climb speed (OCS), a pitch attitude control signal (Upitch) is determined that is adapted so that the rotorcraft accelerates in application of a profile (P1, P2, P3) that varies as a function of the elapsed time and as a function of the operating state of the engines (OEI/AEO).

대표청구항 ▼

What is claimed is: 1. A method of piloting a rotorcraft having a plurality of engines and at least one lift and propulsion rotor, wherein so long as the rotorcraft has not reached an optimum climb speed (OCS), a pitch attitude control signal (Upitch) is determined that is adapted to cause the roto

What is claimed is: 1. A method of piloting a rotorcraft having a plurality of engines and at least one lift and propulsion rotor, wherein so long as the rotorcraft has not reached an optimum climb speed (OCS), a pitch attitude control signal (Upitch) is determined that is adapted to cause the rotorcraft to acquire and maintain an acceleration (A1, A2, A3, A4) that varies as a function of elapsed time in application of a determined acceleration profile (P1, P2, P3), which profile varies as a function of the engine operating state (OEI/AEO); in which, after the pilot of the rotorcraft has engaged the corresponding automatic pilot mode, and during takeoff, so long as no engine is inoperative, a pitch attitude control signal is generated so that the acceleration of the rotorcraft follows a first profile or curve (P1) including at least a first acceleration value (A1) and a second acceleration value (A2) distinct from the first acceleration value, wherein the acceleration of the rotorcraft is maintained substantially constant and equal to the first acceleration value for a first time interval and the second acceleration value for a second time interval, and in the event of an engine becoming inoperative, the pitch attitude control signal is generated in such a manner that the acceleration of the rotorcraft follows a second profile (P2) distinct from the first profile, and including at least a third acceleration value (A3) followed by a fourth acceleration value (A4) distinct from the third acceleration value, wherein the acceleration of the rotorcraft is maintained substantially constant and equal to the third acceleration value for a first time interval calculated for the second profile (P2) and the fourth acceleration value for a second time interval calculated for the second profile (P2), with activation of the pitch attitude control being initiated by the pilot after a minimum safety height has been acquired relative to obstacles. 2. A method according to claim 1, in which the pitch attitude control order is generated to follow one of the profiles (P1, P2) after a critical height has been reached. 3. A method according to claim 1, in which, so long as no engine is inoperative, the pitch attitude control signal is determined so as to maintain the acceleration of the rotorcraft substantially constant and equal to said first acceleration value so long as a takeoff safety speed (TOSS) has not been reached, and then, when said speed is reached, the pitch attitude control signal is determined so as to maintain the acceleration of the rotorcraft substantially constant and equal to said second acceleration value so long as the optimum climb speed (OCS) is not reached, said second acceleration value being less than said first acceleration value. 4. A method according to claim 1, in which, in the event of an engine failure being detected, a pitch attitude control signal is determined so as to maintain the acceleration of the rotorcraft substantially constant and equal to said third acceleration value so long as a takeoff safety speed (TOSS) has not been reached, and then, when said speed is reached, the pitch attitude control signal is determined so as to maintain said speed constant until receiving an acceleration order from the pilot, and the pitch attitude control signal is then determined so as to maintain the acceleration of the rotorcraft substantially constant and equal to said fourth acceleration value for a second time interval calculated for the second profile (P2) and so long as optimum climb speed (OCS) is not reached, said fourth acceleration value being less than said third acceleration value for a first time interval calculated for the second profile (P2) and. 5. A method according to claim 4, in which said fourth acceleration value is automatically adjusted as a function of the power available. 6. A method according to claim 1, in which said third acceleration value is greater than said first acceleration value. 7. A method according to claim 6, in which said first and second acceleration values are less than said third acceleration value and are greater than said fourth acceleration value. 8. A method according to claim 1, in which the acceleration values (A1-A4) are situated in a range extending from about 0.2 m/s2 to about 4 m/s2. 9. A method according to claim 1, in which a collective pitch control signal (Ucoll) is also determined that varies as a function of the engine operating state (OEI/AEO). 10. A method according to claim 9, in which the collective pitch control signal (Ucoll) is generated by means of a vertical target relationship (19) that is peak limited in a manner determined by a relationship (22) seeking to maintain a maximum authorized power when the engines are operating normally, or to maintain a minimum speed of rotation (Nr) for the lift and propulsion rotor after an engine has failed. 11. A program stored on a non-transitory computer readable medium usable by a multi-engine rotorcraft computer to pilot the rotorcraft, the program enabling the rotorcraft to be piloted in application of a method in accordance with claim 1.