System and method for maximizing aircraft safe landing capability during one engine inoperative operation

Patent metadata

Field	Value
Publication number	US-9567091-B2
Application number	US-201414297159-A
Country	US
Kind code	B2
Filing date	Jun 5, 2014
Priority date	Jun 6, 2013
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A method of preserving rotor speed during a one engine inoperative operation of an rotorcraft, the method can include: detecting a failure of a first engine; monitoring an engine parameter associated with a second engine; using a computer processor to compare the engine parameter to an engine limit; and commanding a decrease collective pitch command when the engine parameter is within a predefined range of the engine limit.

First claim

The invention claimed is:

1. A method of preserving a rotor speed of a rotor system during a one engine inoperative operation of a rotorcraft, the method comprising:
monitoring an engine parameter of an engine;
comparing, using a computer processor, the engine parameter to an engine limit, the engine limit being an upper operating limit of the engine;
governing the rotor speed of the rotor system by controlling a power of the engine;
ceasing the governing of the rotor speed of the rotor system by controlling the power of the engine, when the engine parameter reaches the engine limit, and
automatically commanding a decrease collective pitch command with a computer controller in response to the engine parameter reaching the engine limit, such that a pitch of a plurality of rotor blades in the rotor system is decreased so as to preserve the rotor speed of the rotor system.

2. The method according to claim 1 , wherein the engine parameter is an engine torque of the engine.

3. The method according to claim 1 , wherein the engine parameter is a measured gas temperature of the engine.

4. The method according to claim 1 , wherein the engine parameter is a gas generator speed (Ng) of the engine.

5. The method according to claim 1 , wherein the engine parameter is a transmission torque.

6. The method according to claim 1 , wherein step of automatically commanding the decrease collective pitch command occurs after a decrease in the rotor speed below a commanded rotor speed.

7. The method according to claim 1 , wherein step of automatically commanding the decrease collective pitch command causes the rotor speed to increase.

8. A method of preserving a rotor speed of a rotor system during a one engine inoperative operation of a rotorcraft, the method comprising:
detecting a failure of a first engine;
monitoring an engine parameter associated with a second engine;
using a computer processor to compare the engine parameter to an engine limit, the engine limit being an upper operating limit of the second engine;
governing the rotor speed of the rotor system by controlling a power of the second engine;
ceasing the governing of the rotor speed of the rotor system by controlling the power of the second engine, when the engine parameter reaches the engine limit, and
commanding a decrease collective pitch command with a computer controller in response to the engine parameter reaching a predefined range of the engine limit, such that a pitch of a plurality of rotor blades in the rotor system is decreased so as to preserve the rotor speed of the rotor system.

9. The method according to claim 8 , wherein the engine parameter is an engine torque of the second engine.

10. The method according to claim 8 , wherein the engine parameter is a measured gas temperature of the second engine.

11. The method according to claim 8 , wherein the engine parameter is an engine gas generator speed of the second engine.

12. The method according to claim 8 , wherein the engine parameter is a transmission torque of a transmission.

13. The method according to claim 8 , wherein step of commanding the decrease collective pitch command occurs after a decrease in the rotor speed below a commanded rotor speed.

14. A system for preserving a rotor speed of a rotor system during a one engine inoperative operation of a rotorcraft, the system comprising:
an engine;
a computer having a control law, the control law operable to monitor an engine parameter associated with the engine and compare the engine parameter to an engine limit, the control law further operable to govern the rotor speed of the rotor system by controlling a power of the engine, but then ceasing the governing of the rotor speed of the rotor system with the power of the engine when the engine parameter reaches the engine limit, and the computer further operable to command a decrease collective pitch command in response to the engine parameter reaching the engine limit, such that a pitch of a plurality of rotor blades in the rotor system is decreased so as to preserve the rotor speed of the rotor system.

15. The system according to claim 14 , further comprising:
a collective actuator in communication with the computer, the collective actuator configured to change the pitch of the plurality of rotor blades in the rotor system upon actuation of the collective actuator.

16. The system according to claim 14 , further comprising:
a sensor for measuring an engine torque of the engine;
wherein the engine parameter is the engine torque.

17. The system according to claim 14 , further comprising:
a sensor for measuring a gas temperature of the engine;
wherein the engine parameter is the gas temperature.

18. The system according to claim 14 , further comprising:
a sensor for measuring a gas generator speed of the engine;
wherein the engine parameter is the gas generator speed.

19. The system according to claim 14 , wherein the command to decrease collective pitch command occurs in response to a decrease in the rotor speed below a commanded rotor speed.

Assignees

• Bell Helicopter Textron Inc

Inventors

• Schaeffer Joseph M
• Patel Jignesh
• O'Neill Eric

Classifications

• G05D1/0072 Primary

  to counteract a motor failure · CPC title

• B64C27/57

  automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust · CPC title

• B64C19/00

  Aircraft control not otherwise provided for · CPC title

• B64C27/54

  Mechanisms for controlling blade adjustment or movement relative to rotor head, e.g. lag-lead movement · CPC title

• B64D31/00 Primary

  Power plant control systems; Arrangement of power plant control systems in aircraft · CPC title