Aircraft Age-Related Degradation Study on Single- and Three-Phase Circuit Breakers
Abstract
This report provides technical data and brief observations generated for a controlled series of tests on circuit breakers removed from an aging Boeing 727-232 and a McDonnell Douglas DC-10 aircraft. The test program is divided into two groups (Process 1 and Process 2). Sixty circuit breakers in Process 1 were tested for 200% and 500% current overloads. Two hundred forty circuit breakers in Process 2 were tested for voltage drop at rated current, minimum and maximum limits of ultimate trip, 150% and 200% low current overload, and 400% to 500% high current overload. The low voltage contact resistance and temperature rise were continuously monitored. This report also contains a summary of results generated by the FAA Airworthiness Assurance Nondestructive Inspection Validation Center located at Sandia National Laboratories on circuit breakers removed from three aged aircraft. The results of the tests protocols indicated that circuit breakers installed in aircraft with extended service life will continue to protect the electrical wire provided the maintenance procedures recommended in the report are performed annually. The report also recommends proposed changes to SAE Aero-Space Standards to improve circuit protection on future aircraft. This report also contains technical data generated by the FAA Airworthiness Assurance Nondestructive Inspection Validation Center on circuit breakers removed from three retired aircraft. The most significant result of this study is a 39% failure rate in the 114% to 138% current overload ranges. The value and impact of this study still needs to be determined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2002
- Accession Number
- ADA409465
Entities
People
- Joseph Kurek
- Ronnie G. Peterson
Organizations
- RTX