In-Flight Acoustic Emission Monitoring

  • Gary G. Martin


A miniaturised acoustic emission (AE) monitoring system has been installed in a high performance jet trainer to monitor inflight growth of a known crack in a critical structural member. It has been demonstrated that valid AE can be collected even in this hostile environment. Spurious data from background noise have been eliminated using a suitable frequency bandpass and a zone-isolation technique. A linear correlation between valid AE and increase in crack length, measured independently using a magnetic rubber inspection technique, has been obtained. The AE data can also be used to characterise the aircrafts’ flight regime; most AE occurs under rapid dynamic loading conditions typical of low flying.


Acoustic Emission Acoustic Emission Signal Acoustic Emission Event Monitor Unit Acoustic Emission Activity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Hutton, P. H. and Skorpik, J. R., “AE Monitoring Simplified Using Digital Memory Storage and Source Isolation,” Mater Eval, 35 (11), 1977, 55–60.Google Scholar
  2. 2.
    Hutton, P. H. and Skorpik, J. R., “Develop the Application of a Digital Memory Acoustic Emission System to Aircraft Flaw Monitoring,” PNL-2873 UC-37, December 1978.CrossRefGoogle Scholar
  3. 3.
    Mizell, M. E. and Lundy, W. T., Jr., In-flight Crack Detection System for the C-135 Lower Center Wing Skin, ISA ASI 76240, 1976, 254–258.Google Scholar
  4. 4.
    Bailey, C. D. and Pless, W. M., “Acoustic Emission Structure-Borne Background Noise Measurements on Aircraft during Flight,” Mater Eval, 34 (9), 1976, 189–195, 201.Google Scholar
  5. 5.
    Rogers, J., “PRAM PROJECT — The F-105 Acoustic Monitor,” Final Report USAF PRAM Program, July 1979.Google Scholar
  6. 6.
    Rogers, J., 2nd Annual AE In-Flight Monitoring Workshop AETC, Sacramento, CA, March 1979.Google Scholar
  7. 7.
    Carlyle, J., Ibid. 2nd Annual AE In-Flight Monitoring Workshop AETC, Sacramento, CA, March 1979Google Scholar
  8. 8.
    Patterson, A. K., Private Communication.Google Scholar
  9. 9.
    Martin, G. G., “Acoustic Emission Monitoring During Fatigue Testing of a Macchi Boom,” Presented at 2nd Annual Acoustic Emission In-Flight Monitoring Workshop, AETC, Sacramento, CA, March 1979.Google Scholar
  10. 10.
    Ryman, R. J. and Blackwell, M. P., “An Acoustic Emission Investigation of the Initiation and Propagation of Fretting Fatigue Cracks in BS265 Aluminium Alloy under Constant and Random Amplitude Loading,” Rep. No. FAT/130, ISSUE 2 FOR M.O.D. PE AIRCRAFT EST, FARNBOROUGH, September 1977.Google Scholar
  11. 11.
    Green, G. and Walker, E. F., “Acoustic Emission During Fatigue Crack Growth in AISI 4340 Steel,” NDT 78, Aston University, U. K. 1978.Google Scholar
  12. 12.
    Green, R. E., Jr., and Pond, R. B., Sr., “Ultrasonic and Acoustic Emission Detection of Fatigue Damage,” AFOSR TR-78–1284, July 1978.Google Scholar
  13. 13.
    Martin, G. G., “Effect of Strain Rate on Acoustic Emission from Aluminium Alloys,” 9th World Conference on Non-destructive Testing, Melbourne, Australia, November 1979, 4J–4.Google Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • Gary G. Martin
    • 1
  1. 1.Aeronautical Research Laboratories, Defence Science and Technology OrganisationDepartment of DefenceMelbourneAustralia

Personalised recommendations