Aircraft-engine trend monitoring system

• US 7,979,192 B2
• Filed: 03/30/2007
• Issued: 07/12/2011
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Guardian Mobility Inc.
• Original Assignee: Gmc Guardian Mobility Corporation
• Inventors: Wilkinson, Ronald E., Hanvey, Stephan A., Morrison, Brian D.
• Primary Examiner(s): Nguyen; Cuong H
• Application Number:
  US11/693,834
• Publication Number:
  US 20070260374A1
• Time in Patent Office: 1,565 Days
• Field of Search: 701/100, 701/99, 701/102, 701 33- 35, 702/179, 702/186, 702182-183, 244 75- 999
• US Class Current: 701/99
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: G05B 23/0232 based on qualitative trend analysis, e.g. system evolution
• CPC Class Codes: G07C 5/085 using electronic data carriers
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Methods and systems for aircraft engine trend monitoring include periodically recording the outputs of engine-condition sensors and analyzing the results to examine piston-engine performance trends and predict the need for engine maintenance. Various analyses can be performed, separately or in parallel, including comparing the current parameter values with values recorded for that parameter in previous instances of similar operating conditions; comparing parameter values to predetermined nominal ranges; and detecting parameter values that exhibit trends over time that if followed would result in out-of-bound readings. Sensed parameter values can also be used to detect when recommended engine operating conditions are being exceeded. By using the results of the analyses to inform engine maintenance scheduling and provide alerts to the pilot and maintenance staff regarding recommended engine performance trends and/or operating condition exceedances, the methods and systems contribute to enhancing the level of safety that can be achieved despite significant maintenance-budget reductions.

Claims

1. A computer-implemented method for periodically monitoring performance of an engine in an aircraft during flight operations for predicting future engine problems, comprising:

(a) receiving at a computer system engine performance data, environmental data, and flight data during use of the engine;

(b) determining, using the computer system, if the engine is operating within a predetermined parameter set;

(c) when the engine is operating within the predetermined parameter set and the aircraft is determined to be operating in a stable cruise regime, comparing, using the computer system, the engine performance data with previous engine performance data from at least one previous use of the same engine when the engine was operating within the predetermined parameter set taking into account the environmental data and flight data associated with the engine performance data and the previous engine performance data;

(d) outputting, from the computer system, results of step (c); and

(e) repeating steps (a) through (d) on successive flights of the aircraft.

2. The method of claim 1, further comprising controlling the engine to operate within the predetermined parameter set.

3. The method of claim 1, wherein the engine is a piston engine.

4. The method of claim 1, further comprising predicting a future excursion of an engine performance parameter beyond allowable tolerance limits based on trend analysis of results of step (c).

5. The method of claim 1, further comprising storing the results of step (c) in memory to be used in subsequent analyses of engine performance data.

6. The method of claim 2, wherein controlling the engine comprises:

maintaining a certain altitude to allow the engine to stabilize;

setting the engine at a recommended percent cruise power; and

setting a fuel mixture to one of a recommended best power mixture and recommended best economy mixture.

7. The method of claim 6, wherein the recommended percent cruise power is set at 72%±

2% and the best power mixture is set at 75°

F.±

10°

F. rich of peak exhaust gas temperature.

8. The method of claim 3, wherein:

obtaining the performance data comprises obtaining at least one instrument output taken from a listing of instrument outputs including oil temperature, oil pressure, manifold pressure, engine speed, fuel flow, cylinder head temperature and exhaust gas temperature; and

obtaining the environmental data comprises obtaining at least one instrument output taken from a listing of instrument outputs including true airspeed, indicated airspeed, pressure altitude, density altitude, outside air temperature, and vertical speed.

9. The method of claim 8, wherein comparing comprises:

obtaining a predicted value for at least one instrument output;

storing a difference between the predicted value and an actual value of the at least one instrument output to a current trend record; and

storing other instrument outputs to the current trend record.

10. The method of claim 9, wherein obtaining previous performance data comprises determining if trend records for a predetermined number of previous uses are stored.

11. The method of claim 8, wherein comparing comprises obtaining averages for values stored in the trend records for previous uses and comparing values of the current trend record to corresponding averages from the trend records of previous uses.

12. The method of claim 11, wherein outputting comprises:

displaying values of the current trend record;

displaying the corresponding averages; and

displaying tolerances associated with respective values of the current trend record.

13. The method of claim 12, wherein displaying comprises displaying values associated with instrument outputs taken from a listing of instrument outputs including engine speed, manifold pressure, fuel flow, air speed, altitude, oil temperature, oil pressure, maximum cylinder head temperature, minimum cylinder head temperature, maximum exhaust gas temperature, exhaust gas temperature of the first cylinder to peak and exhaust gas temperature of the last cylinder to peak.

14. The method of claim 11, wherein obtaining averages comprises obtaining averages for chronological groupings of trend records for previous uses.

15. The method of claim 8, wherein obtaining performance data comprises providing an indication to an operator when a value of at least one of the instrument outputs differs from a predicted value by more than a predetermined tolerance.

16. The method of claim 15, further comprising obtaining the predicted value from a lookup table.

17. The method of claim 16, further comprising performing interpolation calculations within the lookup table.

18. The method of claim 8, wherein obtaining performance data comprises periodically obtaining and recording at least one instrument output for each of the performance data and the environmental data.

19. The method of claim 18, wherein outputting further comprises displaying a historical record of the periodically obtained at least one instrument output.

20. The method of claim 1, wherein obtaining performance data comprises providing an indication to an operator when a value of at least one of the performance data differs from a predicted value by more than a predetermined tolerance.

21. The method of claim 20, further comprising obtaining the predicted value from a lookup table.

22. The method of claim 21, further comprising performing interpolation calculations within the lookup table.

23. The method of claim 1, wherein comparing comprises:

obtaining predicted values for the engine performance data based in part on the environmental data; and

storing differences between the predicted values and actual values of the engine performance data to a current trend record.

24. The method of claim 23, wherein obtaining previous performance data comprises determining if trend records for a predetermined number of previous uses are stored.

25. The method of claim 24, wherein comparing comprises obtaining averages for values stored in the trend records for previous uses and comparing values of the current trend record to corresponding averages from the trend records of previous uses.

26. The method of claim 25, wherein outputting comprises:

displaying values of the current trend record;

displaying the corresponding averages; and

displaying tolerances associated with respective values of the current trend record.

27. The method of claim 1, wherein step (b) comprises determining if the engine is operating within a predetermined parameter set within an acceptable tolerance limit for each parameter in the parameter set using the engine performance data, the environmental data, and the flight data.

28. The method of claim 1, wherein step (c) further comprises comparing the engine performance data with predicted performance values for the engine based in part on the environmental data and the flight data.