US 11,939,073 B2
Starting methods for hybrid-electric aircraft
Paul C. Imel, Hartford, CT (US); Sebastien Bergeron, Chambly (CA); Etienne Plamondon, Verdun (CA); Samuel Gosselin-Brisson, Longueuil (CA); and Leonid Guerchkovitch, Dollard des Ormeaux (CA)
Assigned to PRATT & WHITNEY CANADA CORP., Longueuil (CA)
Filed by Pratt & Whitney Canada Corp., Longueuil (CA)
Filed on Oct. 30, 2020, as Appl. No. 17/085,006.
Prior Publication US 2022/0135240 A1, May 5, 2022
Int. Cl. B64D 31/06 (2006.01); B64D 27/02 (2006.01); B64D 27/24 (2006.01); B64D 35/08 (2006.01); B64D 41/00 (2006.01)
CPC B64D 31/06 (2013.01) [B64D 27/02 (2013.01); B64D 27/24 (2013.01); B64D 35/08 (2013.01); B64D 41/00 (2013.01); B64D 2027/026 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method comprising:
setting a start speed for a thermal engine of a hybrid-electric power plant in an aircraft based on ambient conditions;
using an electric motor to start the thermal engine by bringing the thermal engine to the start speed and limiting a torque output of the electric motor to prevent mechanical failure when mechanical rotation of the electric motor is hindered, wherein:
the electric motor and thermal engine are connected to one another as the electric motor and the thermal engine of the hybrid-electric power plant in the aircraft;
the electric motor is connected to a combining gear box;
the thermal engine is connected to the combining gear box so that the electric motor and the thermal engine can provide torque to the combining gear box in a parallel hybrid-electric configuration;
flying the aircraft through a mission of take-off, climb, cruise, and landing without using the electric motor as a generator;
after using the electric motor to start the thermal engine:
powering the aircraft with the hybrid-electric power plant with combined power from the electric motor and the thermal engine driving the combining gear box through take-off; and
powering the aircraft with the hybrid-electric power plant with combined power from the electric motor and the thermal engine driving the combining gear box while climbing to cruise altitude.