Automated propeller feather testing

Patent metadata

Field	Value
Publication number	US-2020049027-A1
Application number	US-201916655424-A
Country	US
Kind code	A1
Filing date	Oct 17, 2019
Priority date	May 15, 2015
Publication date	Feb 13, 2020
Grant date	—

Abstract

There is described herein methods and systems for testing a propeller feathering function. The method comprises monitoring a rotational speed over time of propeller blades of an aircraft, commanding an angle change of the propeller blades, comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed without the commanded angle change and obtaining, by the processor, a rotational speed difference, and issuing a test passed signal when the rotational speed difference exceeds a threshold and a test failed signal when the rotational speed difference does not exceed the threshold.

First claim

1 . A computer-implemented method for testing a propeller feathering function, the method comprising:
monitoring, by a processor of a computing device, a rotational speed over time of propeller blades of an aircraft; commanding, by the processor of the computing device, an angle change of the propeller blades; comparing, by the processor of the computing device, a post-angle change rotational speed of the propeller blades to an expected rotational speed without the commanded angle change and obtaining, by the processor, a rotational speed difference; and issuing, by the processor of the computing device, a test passed signal when the rotational speed difference exceeds a threshold and a test failed signal when the rotational speed difference does not exceed the threshold.

2 . The method of claim 1 , wherein the angle change is commanded upon receipt of a trigger signal generated upon initiation of an engine shutdown.

3 . The method of claim 1 , wherein monitoring the rotational speed over time comprises monitoring a rate of change of the rotational speed over time.

4 . The method of claim 3 , wherein comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed comprises comparing the rate of change of the rotational speed of the propeller blades to an expected rate of change of a zero pitch angle propeller.

5 . The method of claim 1 , further comprising detecting an aircraft-on-ground condition, and wherein commanding an angle change of the propeller blades comprises commanding the angle change only when the aircraft-on-ground condition is detected.

6 . The method of claim 1 , further comprising returning the propeller blades to a zero pitch angle after issuing the test passed signal.

7 . The method of claim 1 , wherein commanding an angle change of the propeller blades comprises commanding an angle change to a target blade pitch that is less than a maximum blade pitch.

8 . The method of claim 1 , wherein commanding an angle change of the propeller blades comprises progressively changing a pitch of the propeller blades until a target blade pitch is reached.

9 . The method of claim 8 , wherein comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed comprises comparing until a first one of reaching the target blade pitch and obtaining the rotational speed difference that exceeds the threshold occurs.

10 . The method of claim 1 , wherein commanding an angle change of the propeller blades comprises increasing a blade pitch, and wherein comparing the post-angle change rotational speed to the expected rotational speed comprises detecting a decrease in post-angle change rotational speed compared to the expected rotational speed.

11 . The method of claim 1 , wherein commanding an angle change of the propeller blades comprises decreasing a blade pitch, and wherein comparing the post-angle change rotational speed to the expected rotational speed comprises detecting an increase in post-angle change rotational speed compared to the expected rotational speed.

12 . The method of claim 1 , wherein the angle change is commanded upon receipt of a trigger signal generated upon initiation of an engine start-up.

13 . A system for testing a propeller feathering function, the system comprising:
a memory; a processor coupled to the memory; and an application stored in the memory and comprising program code executable by the processor for:
monitoring a rotational speed over time of propeller blades of an aircraft;
commanding an angle change of the propeller blades;
comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed without the commanded angle change and obtaining, by the processor, a rotational speed difference; and
issuing a test passed signal when the rotational speed difference exceeds a threshold and a test failed signal when the rotational speed difference does not exceed the threshold.

14 . The system of claim 13 , wherein the angle change is commanded upon receipt of a trigger signal generated upon initiation of an engine shutdown.

15 . The system of claim 13 , wherein monitoring the rotational speed over time comprises monitoring a rate of change of the rotational speed over time.

16 . The system of claim 15 , wherein comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed comprises comparing the rate of change of the rotational speed of the propeller blades to an expected rate of change of a zero pitch angle propeller.

17 . The system of claim 13 , wherein the program code is further executable for detecting an aircraft-on-ground condition, and wherein commanding an angle change of the propeller blades comprises commanding the angle change only when the aircraft-on-ground condition is detected.

18 . The system of claim 13 , wherein the program code is further executable for returning the propeller blades to a zero pitch angle after issuing the test passed signal.

19 . The system of claim 13 , wherein commanding an angle change of the propeller blades comprises commanding an angle change to a target blade pitch that is less than a maximum blade pitch.

20 . The system of claim 13 , wherein commanding an angle change of the propeller blades comprises progressively changing a pitch of the propeller blades until a target blade pitch is reached.

21 . The system of claim 20 , wherein comparing a post-angle change rotational speed of the propeller blades to an expected rotational speed comprises comparing until a first one of reaching the target blade pitch and obtaining the rotational speed difference that exceeds the threshold occurs.

22 . The system of claim 13 , wherein commanding an angle change of the propeller blades comprises increasing a blade pitch, and wherein comparing the post-angle change rotational speed to the expected rotational speed comprises detecting a decrease in post-angle change rotational speed compared to the expected rotational speed.

23 . The system of claim 13 , wherein commanding an angle change of the propeller blades comprises decreasing a blade pitch, and wherein comparing the post-angle change rotational speed to the expected rotational speed comprises detecting an increase in post-angle change rotational speed compared to the expected rotational speed.

24 . The system of claim 13 , wherein the angle change is commanded upon receipt of a trigger signal generated upon initiation of an engine start-up.

Assignees

• Pratt & Whitney Canada

Inventors

• Duke Brant
• Matheson Kenneth

Classifications

• B64C11/325

  comprising feathering, braking or stopping systems · CPC title

• F01D21/003 Primary

  Arrangements for testing or measuring (for measuring vibrations G01H) · CPC title

• B64C11/385

  comprising feathering, braking or stopping systems · CPC title

• B64C11/30

  Blade pitch-changing mechanisms · CPC title

• B64C11/06

  for variable-pitch blades · CPC title