US 12,435,674 B2
System and method for operating a turboprop engine
Nicolas Des Roches-Dionne, Longueuil (CA); Sylvain Lamarre, Boucherville (CA); and Alexandre Charest, Montreal (CA)
Assigned to PRATT & WHITNEY CANADA CORP., Longueuil (CA)
Filed by PRATT & WHITNEY CANADA CORP., Longueuil (CA)
Filed on Aug. 26, 2019, as Appl. No. 16/551,177.
Claims priority of provisional application 62/879,066, filed on Jul. 26, 2019.
Prior Publication US 2021/0025338 A1, Jan. 28, 2021
Int. Cl. B64D 31/06 (2024.01); B64D 27/10 (2006.01); F02C 9/28 (2006.01); B64C 11/30 (2006.01); F02C 9/44 (2006.01); F02C 9/58 (2006.01)
CPC F02C 9/28 (2013.01) [B64D 31/06 (2013.01); F02C 9/44 (2013.01); F05B 2270/1031 (2013.01); F05D 2270/02 (2013.01); F05D 2270/051 (2013.01); F05D 2270/052 (2013.01); F05D 2270/304 (2013.01); F05D 2270/335 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for transitioning a turboprop engine of an aircraft out of and into an idle operating regime of the turboprop engine, the method comprising:
obtaining a power governing schedule defining at least one upper gas generator speed (Ng) limit and at least one lower Ng limit of the turboprop engine, the at least one upper Ng limit defining a maximum Ng that varies as a function of a power lever position of the aircraft for producing forward thrust with a propeller of the turboprop engine and beyond an idle power lever position, the at least one lower Ng limit defining a minimum Ng that varies as a function of the power lever position, the at least one upper Ng limit and the at least one lower Ng limit diverging from the idle power lever position to define a progressive transition out of and into the idle operating regime of the turboprop engine;
receiving a target power for the turboprop engine corresponding to a current power lever position, the current power lever position corresponding to forward thrust operation of the propeller of the turboprop engine and being beyond the idle power lever position;
selecting, from the power governing schedule, a maximum Ng corresponding to the current power lever position and a minimum Ng corresponding to the current power lever position; and
in response to receiving the target power:
governing output power for the turboprop engine to achieve the target power, governing the output power including determining a requested Ng;
when the requested Ng is between the maximum Ng corresponding to the current power lever position and the minimum Ng corresponding to the current power lever position, using the requested Ng to govern the output power for the turboprop engine;
when the requested Ng is above the maximum Ng corresponding to the current power lever position, using the maximum Ng instead of the requested Ng to govern the output power for the turboprop engine; and
when the requested Ng is below the minimum Ng corresponding to the current power lever position, using the minimum Ng instead of the requested Ng to govern the output power for the turboprop engine.