Usage monitor reliability factor using an advanced fatigue reliability assessment model

• US 8,200,442 B2
• Filed: 09/25/2009
• Issued: 06/12/2012
• Est. Priority Date: 03/16/2009
• Status: Active Grant

• Current Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Original Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Inventors: Adams, David O., Zhao, Jack Z.
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US12/566,743
• Publication Number:
  US 20100235108A1
• Time in Patent Office: 991 Days
• Field of Search: 702/34, 702/185, 701/29, 701/31, 701/29.1
• US Class Current: 702/34
• CPC Class Codes: B64D 2045/0085 Devices for aircraft health monitoring, e.g. monitoring flutter or vibration
• CPC Class Codes: B64F 5/60 Testing or inspecting aircraft components or systems
• CPC Class Codes: G01M 5/00 Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings G01M9/00 takes precedence
• CPC Class Codes: G06Q 10/04 Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem" market predictions or forecasting for commercial activities G06Q30/0202
• CPC Class Codes: G06Q 10/20 Administration of product repair or maintenance

Abstract

According to one non-limiting embodiment, a method includes accessing flight regime rates of occurrence distributions associated with one or more flight regimes for a fleet of aircraft. Using the accessed flight regime distributions, a factor for at least one of the flight regimes is determined that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime.

Claims

1. A method comprising:

accessing flight regime rates of occurrence distributions associated with one or more flight regimes for a fleet of aircraft, the one or more flight regimes are one or more predicted maneuvers performed during a flight; and

determining, using the accessed flight regime rates of occurrence distributions, a factor for at least one of the flight regimes that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime.

2. The method as recited in claim 1, wherein the occurrence distributions include a plurality of usage counts, the method further including:

multiplying the plurality of usage counts of the component by the factor.

3. The method as recited in claim 1, the method further including:

dividing a retirement damage level for the component by the factor.

4. The method as recited in claim 1, modifying a lifetime of the component for a selected one of the aircraft from the fleet in response to the factor.

5. The method as recited in claim 1, wherein said determining, using the accessed flight regime distributions, a factor for at least one of the flight regimes that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime includes:

A) identifying a critical flight regime from the occurrence distribution;

B) determining a 90th percentile usage value for the critical flight regime in the occurrence distribution;

C) determining a 50th percentile usage value for the critical flight regime in the occurrence distribution; and

D) defining the factor as a ratio between the 90th percentile and 50th percentile usage values for the critical flight regime.

6. The method as recited in claim 5, wherein said determining, using the accessed flight regime distributions, a factor for at least one of the flight regimes that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime further includes:

E) selectively repeating steps (A)-(D) for each of a plurality of critical flight regimes; and

F) defining the factor as a weighted average of factors for individual critical flight regimes.

7. The method as recited in claim 1, wherein said determining, using the accessed flight regime distributions, a factor for at least one of the flight regimes that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime includes:

determining a Weibull plot of the occurrence distribution for one of the flight regimes; and

defining the factor for a selected critical flight regime as a ratio between a 90th percentile Weibull plot usage value and a 50th percentile Weibull plot usage value for the flight regime.

8. The method as recited in claim 1, wherein the distributions include a plurality of usage counts, the method further including:

verifying that the factor achieves a required 0.999999 reliability.

9. The method as recited in claim 1, wherein the distributions include a plurality of flight usage counts, the method further including:

determining component retirement life while maintaining a required 0.999999 reliability.

10. The method as recited in claim 1, wherein the one or more predicted maneuvers includes a turn performed during a flight.

11. The method as recited in claim 1, wherein the one or more predicted maneuvers includes a landing.

12. The method as recited in claim 1, wherein said determining of the factor includes identifying a critical flight regime from the occurrence distribution.

13. The method as recited in claim 1, wherein said determining of the factor includes determining a ratio between percentile usage values of a flight regime.

14. The method as recited in claim 1, wherein said determining of the factor includes:

A) identifying a critical flight regime from the occurrence distributions;

B) determining a first percentile usage value for the critical flight regime in the occurrence distribution;

C) determining a second percentile usage value for the critical flight regime in the occurrence distribution; and

D) defining the factor as a ratio between the first percentile usage value and the second percentile usage value for the critical flight regime.

15. A method comprising

accessing flight regime rates of occurrence distributions associated with one or more flight regimes for a fleet of aircraft;

and

determining, using the accessed flight regime rates of occurrence distributions, a factor for at least one of the flight regimes that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime, including;

A) identifying a critical flight regime from the occurrence distribution by comparing a usage assumption for a flight regime to an actual usage count for the flight regime and

identifying the flight regime as critical in response to an amount of fatigue damage contributed by the flight regime'"'"'s occurrence rate to a calculation of component retirement time exceeding a predefined threshold,

B) determining a 90th percentile usage value for the critical flight regime in the occurrence distribution,

C) determining a 50th percentile usage value for the critical flight regime in the occurrence distribution, and

D) defining the factor as a ratio between the 90th percentile and 50th percentile usage values for the critical flight regime.

16. A method performed by a computer either on-board an aircraft or remote from the aircraft, comprising:

receiving a usage monitoring reliability factor associated with a component on an aircraft, and the usage monitoring reliability factor is a ratio between percentile usage values of a flight regime;

multiplying aircraft usage cycles by the factor to determine adjusted usage data;

adjusting, using at least the factor, a lifetime of the component in response to the adjusted usage data; and

displaying the adjusted lifetime of the component.

25. The method as recited in claim 16, wherein the flight regime is a predicted maneuver performed during a flight.

26. The method as recited in claim 16, wherein the lifetime of the component is divided by the factor to determine the adjusted lifetime of the component.

27. The method as recited in claim 16, wherein a current lifetime of the component is displayed as a percentage of the adjusted lifetime on an aircraft display system.

17. A method comprising:

accessing flight regime rates of occurrence distributions associated with one or more flight regimes for a fleet of aircraft; and

determining, using the accessed flight regime rates of occurrence distributions, a factor for at least one of the flight regimes that provides a predetermined amount of reliability for a component on each aircraft on the fleet of aircraft known to be affected through at least fatigue damage by the at least one flight regime;

determining, using at least the factor, instructions to modify a lifetime of the component for a selected one of the aircraft from the fleet; and

communicating the instructions to an entity configured to use the instructions to modify the lifetime of the component.

18. The method as recited in claim 17, wherein the instructions comprise signals on a computer readable medium configured to cause a computer on the selected aircraft to adjust a lifetime of the component by the factor.

19. The method as recited in claim 17, further comprising displaying indicia corresponding to the lifetime of the component to a user of the selected helicopter.

20. The method as recited in claim 17, wherein the instructions facilitate adjustment to the lifetime of the component.

21. The method as recited in claim 17, wherein the method is performed on a computer either on-board the aircraft or remote from the aircraft.

22. An apparatus comprising a computer configured through a non-transitory computer-readable storage medium to perform the operations of:

determining a fatigue reliability of an aircraft component in response to at least one of flight usage data, flight load data, historical data, and a fatigue reliability assessment model; and

using usage distributions to determine;

a factor for at least one flight regime that provides a usage count adjustment for the component for each aircraft of a fleet known to be affected through at least fatigue damage by the at least one flight regime, and the at least one flight regime is one or more predicted maneuvers performed during a flight.

23. The apparatus as recited in claim 22, wherein the one or more predicted maneuvers includes a turn performed during a flight.

24. The apparatus as recited in claim 22, wherein the one or more predicted maneuvers includes a landing.