Journal of the Korean Society for Aviation and Aeronautics (한국항공운항학회지)

The Korean Society for Aviation and Aeronautics (한국항공운항학회)
권호 표지
DOI QR코드

DOI QR Code

EWIS Reliability Analysis of Aging Fighter Aircraft through Teardown Inspection

완전분해 점검을 통한 장기운영 전투기 전기배선시스템의 신뢰성분석

  • Received : 2018.11.22
  • Accepted : 2018.12.27
  • Published : 2018.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

According to the incresement of aging aircraft, Republic of Korea Air Force (RoKAF) conducted a teardown inspection of aircraft's EWIS (electrical wiring interconnection system) to determine the status of deterioration and the influence of failure occurrences due to it. The inspected aircraft were the retired fighter jets that had been used for more than 40 years. By analyzing defect type and the defect tendency, RoKAF can establish the necessary measures for the usage extension of their fleet and furthermore, the analysis results can be used as a basic data for the preparation of it's aircraft aging. EWIS inspection was done throughout careful visual inspection technique by removing all the ducts and pipes located in the fuselage and wings. For the aircraft wiring where no damage was found, the elongation tests were performed to determine the deterioration of wiring according to the location of the aircraft. The connectors, which is the main cause of intermittent failure, were completely disassembled and inspected for internal damage such as corrosion, abrasion, and traces of foreign objects. The detected defects were classified into 4 severity levels based on the type of damage, and the classified defects were weighted according to the criticality which may affects to it's system to establish the action plan.

Keywords

HHOHB8_2018_v26n4_116_f0001.png 이미지

Fig 1. Defect distribution of F-4 EWIS

HHOHB8_2018_v26n4_116_f0002.png 이미지

Fig 2. Defect distribution of F-5 EWIS

HHOHB8_2018_v26n4_116_f0003.png 이미지

Fig 3. Defects type of aging aircraft EWIS

HHOHB8_2018_v26n4_116_f0004.png 이미지

Fig 4. Classification of wire defect

HHOHB8_2018_v26n4_116_f0005.png 이미지

Fig 5. Defective component distribution of F-4 EWIS

HHOHB8_2018_v26n4_116_f0006.png 이미지

Fig 6. Defective component distribution of F-5 EWIS

HHOHB8_2018_v26n4_116_f0007.png 이미지

Fig 7. Elongation test result of #20 Wire

HHOHB8_2018_v26n4_116_f0008.png 이미지

Fig 8. Elongation test result of #22 Wire (F-4)

HHOHB8_2018_v26n4_116_f0009.png 이미지

Fig 9. Elongation test result of #22 Wire (F-5)

HHOHB8_2018_v26n4_116_f0010.png 이미지

Fig 10. Example of a connector inspection

HHOHB8_2018_v26n4_116_f0011.png 이미지

Fig 11. Quantitative condition rating result (F-4)

HHOHB8_2018_v26n4_116_f0012.png 이미지

Fig 12. Quantitative condition rating result (F-5)

Table 1. EWIS defects by type

HHOHB8_2018_v26n4_116_t0001.png 이미지

Table 2. Criteria for condition code assignment of defect

HHOHB8_2018_v26n4_116_t0002.png 이미지

References

  1. NTSB, "Aircraft Accident Report: In-flight breakup over the Atlantic Ocean Trans World Airlines Flight 800", NTSB/AAR-00/03, Aug, 2000.
  2. C. Furse and R. Haupt, "Down to the wire", IEEE spectrum, February, 2001, pp.34-39.
  3. H. Lee, C. Yoo, C. Han and J. Jang, "Study on Intermittent Failure occurring in Aged Aircraft Wiring", Spring Conference of the Korean Society of Mechanical Engineers Reliability Engineering Division, Jeju, Korea, February 21-23, 2018
  4. USAF, "Installation and repair practices: Aircraft electric and electronic wiring", TO 1-1A-14, 2009.
  5. FAA, "Aircraft Wiring Degradatio Study", DOT/FAA/AR-08/2, Jan, 2008.
  6. DLA, "Federal Standard: Test Methods for Cables and Wire, Insulated", FED-STD-228A, Apr, 2014.
  7. Haiyu Qi, Sanka Ganesan, Michael Pecht, "No-fault-found and intermittent failures in electronic products", Microelectronics Reliability, No. 48, 2008, pp. 663-674.
  8. H. Lee, "A Study on the Improvement of the Domestic Maintenance Capability Development System of Military for Overseas Maintenance Items through the Case Study of Intermittent Failure of an Avionics", Journal of the Korea Society for Aviation and Aeronautics, Vol. 26, No. 2, Jun, 2018, pp. 68-75. https://doi.org/10.12985/KSAA.2018.26.2.068
  9. Alan Kruppa, "Aging wire characterization: Qualitative condition rating methodology", AA&S conference 2010, Austin, May 10-13, 2010.