US 12,297,781 B2
Operating an aircraft
Peter Swann, Derby (GB); Craig W Bemment, Derby (GB); Alastair G Hobday, Derby (GB); Benjamin J Keeler, Derby (GB); and Christopher P Madden, Derby (GB)
Assigned to ROLLS-ROYCE plc, London (GB)
Filed by ROLLS-ROYCE plc, London (GB)
Filed on May 26, 2023, as Appl. No. 18/324,619.
Application 18/324,619 is a continuation of application No. 17/853,074, filed on Jun. 29, 2022, granted, now 11,815,031.
Claims priority of application No. 2118656 (GB), filed on Dec. 21, 2021.
Prior Publication US 2023/0296060 A1, Sep. 21, 2023
Int. Cl. F02C 9/28 (2006.01); B64D 27/10 (2006.01); B64D 37/04 (2006.01); G08G 5/00 (2006.01); G08G 5/32 (2025.01)
CPC F02C 9/28 (2013.01) [B64D 27/10 (2013.01); B64D 37/04 (2013.01); G08G 5/32 (2025.01)] 19 Claims
OG exemplary drawing
 
1. A method of operating an aircraft comprising a gas turbine engine and a plurality of fuel tanks arranged to provide fuel to the gas turbine engine, wherein at least two of the fuel tanks contain fuels with different fuel characteristics, the method comprising:
obtaining a flight profile for a portion of a flight of the aircraft during one or more of take-off, climb, cruise, descent, approach, and landing;
determining a fuelling schedule for the portion of the flight based on the flight profile and the fuel characteristics, the fuelling schedule governing the variation with time of how much fuel is drawn from each tank; and
controlling fuel input to the gas turbine engine in operation in accordance with the fuelling schedule, the controlling including switching from taking fuel from one of the fuel tanks to another of the fuel tanks when a parameter reaches a threshold, the parameter being selected from the group consisting of fuel temperature at an inlet to a combustor of the gas turbine engine, turbine gas temperature, oil temperature, shaft speed, and time since the engine was turned on.