Avionics News December 2011 - (Page 54)

series B y t H o M A S i n M A n From ASTRAC to EZAP o avionics technicians, wiring is simple. To others, it’s not. A chain of events, starting with the TWA flight 800 accident, has led our industry to a new way of thinking about wiring and several new acronyms. On July 17, 1996, TWA flight 800 exploded. According to the National Transportation Safety Board, “The source of ignition energy for the explosion could not be determined with certainty, but, of the sources evaluated by the investigation, the most likely was a short circuit outside of the CWT (center wing tank) that allowed excessive voltage to enter it through electrical wiring associated with the fuel quantity indication system.” The NTSB mentioned safety issues related to aging aircraft systems. As a result of the safety improvement recommendations published in 1998, the Federal Aviation Administration created the Aging Transport Systems Rulemaking Advisory Committee in 1999. ASTRAC looked closely at a sampling of the airline fleet and examined wiring. The committee reviewed service history, developed better maintenance criteria, reviewed and updated wiring standard practices, reviewed both air carrier and repair station inspection and training programs and developed recommendations. Photographs created from this review have been shown at many seminars, including the AEA’s Wiring Inspections training program 54 avionics news T available online to AEA members. ASTRAC reported an average of 40 findings on 81 airplanes, and it defined an average of two findings per airplane as significant. Fortunately, there were no immediate safety concerns; however, the numbers are large. This equates to more than 3,000 findings on 81 airplanes in the best maintained fleet in the world. ASTRAC found a host of problems, including: In 2003, the FAA issued a notice of proposed rulemaking addressing certification requirements, wiring practices, training requirements and enhanced maintenance procedures. Along with the NPRM came two more acronyms. The first, EZAP, stands for enhanced zonal analysis procedure. The second, ICAW, stands for instructions for continued airworthiness – wiring. The FAA has a new policy regarding wire A chain of events, starting with the TWA flight 800 accident, has led our industry to a new way of thinking and several new acronyms. • • • • • • • • • • • • • • • • Improper sleeving. Improper tie wrap installation. Foreign object hazards. Improper grommet installation. Damaged conduit. Improper wire routing. Too little slack. Improper clamping. Clamp damage. Improper terminations. Lack of wire marking. Ganged splices. Improper safety wire technique. Contaminated wire bundles. Improper bend radii. Dirt and dust accumulation. installation, new rules and a no fuel tank safety program known as SFAR 88. ASTRAC and NTSB recommendations resulted in the enhanced airworthiness program for airplane systems, or EAPAS. It consists of the FAA offices of certification service, research, system safety and flight standards. ASTRAC is included as well. EAPAS addresses six areas, including training, maintenance, design, research and development, reporting, information sharing and outreach. The FAA sees this as a shift in approach. Wiring is recognized as an important system. EAPAS has mandated • december 2011

Table of Contents for the Digital Edition of Avionics News December 2011

Point of Communication
AEA Now
Before & After
The View From Washington
International News and Regulatory Updates
EFB Solutions
Member Profile
Homebuilders
The Top Avionics Sellers for 2011
A Conversation With...
Alphabets Advocating for Aviation
Meet the AEA Board
Member Profile
Business Basics
Theory & Practice
Meet the AEA Staff
Advertisers Index
AEA Members Make Headlines at NBAA Convention
What's New
Marketplace Classifieds

Avionics News December 2011