US 11,719,167 B2
Operating a turboprop engine for in-flight restart
Simon Lopez, Montreal (CA); and Jeremie Hebert, Napierville (CA)
Assigned to PRATT & WHITNEY CANADA CORP., Longueuil (CA)
Filed by PRATT & WHITNEY CANADA CORP., Longueuil (CA)
Filed on Apr. 1, 2021, as Appl. No. 17/220,008.
Prior Publication US 2022/0316407 A1, Oct. 6, 2022
Int. Cl. F02C 9/16 (2006.01); B64C 11/30 (2006.01); F02C 6/20 (2006.01)
CPC F02C 9/16 (2013.01) [B64C 11/30 (2013.01); F02C 6/206 (2013.01); F05D 2270/021 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for operating an aircraft turboprop engine, the method comprising:
controlling a propeller of the turboprop engine based on a reference propeller rotational speed and a minimum propeller blade angle while the turboprop engine is running;
detecting an inflight restart of the turboprop engine, the detecting of the inflight restart comprising detecting an engine start, and in response to detecting the engine start, detecting the inflight restart using flight conditions; and
controlling the propeller during the inflight restart in accordance with a modified reference propeller rotational speed and a modified minimum propeller blade angle to maintain an actual propeller blade angle above an aerodynamic disking angle and a decreased reference propeller rotational speed during the inflight restart.