Corroded & cracked  fuel quantity indication wire found by AI during an inspection

Shorted Wire

SR 111 Wreckage

Connector contaminated with swarf

Aged wiring & connector

Why do we need to perform Aging Wiring training?

Training is provided at two levels.  The basic level training is intended for non-avionic
or electrical technicians and supervisors and the advanced level is for qualified avionic
or electrical technicians.  Training is considered essential for all technicians that work
on aircraft. Airframe and Engine technicians must clearly understand the criticality of
wiring and take special precautions when working in and around wiring systems,
particularly when producing swarf.  They must also be able to identify degraded wiring, or potential problems such as chafing and report these observations.  Airframe and electrical technicians need to work as a team.

What is the background behind the Aging Wiring Inspection Program?

The Federal Aviation Authority (FAA) in USA established a committee called the Aging Transport System Rulemaking Advisory Committee (ATSRAC) in the late 1990s in response to the 1996 mid-air explosion of TWA Flight 800.   The loss was considered to have been caused by a wiring failure, leading to a spark that ignited fuel in the
centre wing tank.  In 1998 Swissair Flight SR 111 crashed off  Nova
Scotia, again with a total loss of life. Forensic analysis concluded that
the Swissair disaster was also caused by electrical arcing leading to an
uncontrollable fire.

These two tragic events and many other incidents led to the realisation
that wiring systems are as critical to the airworthiness of the aircraft and
the safety of all on board as is the primary structure. Two of the
recommendations made by ATSRAC were for maintenance organisations
to treat wiring as a unique and separate “maintenance item” and to
introduce specialised training for maintenance technicians on the care
and maintenance of aging wiring. 

How are the inspections performed?

An inspection team comprising of an experienced engineer and technician visually inspect the aircraft electrical wiring installations to detect wiring system defects, including degraded wire insulation, damage, corrosion, contamination and incorrect or inappropriate installation in accordance with the relevant specification or standard. To facilitate greatest access to the wiring system, inspections are carried out while the aircraft are undergoing a scheduled major servicing.

Examples of inspections performed

Why do we need to conduct inspections?

CASA, ADF Airworthiness Authority, FAA and indeed all Airworthiness Authorities
have recognised that wiring systems are critical to the safe operation of aircraft.  See
below for background. They have also determined that aging wiring systems can readily
lead to a reduction in the airworthiness of aircraft if maintenance staff:

  • do not understand the criticality of wiring
  • do not treat the wiring with due care
  • are unable to identify degraded wiring or
  • are unable to adequately repair it.

Aging wiring inspections performed by Aerospace Innovations have identified aged
wiring, inadequate wiring husbandry, inadequate training and have contributed to a
significant improvement in the levels of safety.  All aircraft inspected to date have
benefited with improved levels of airworthiness with around 50% reaping major and significant benefits.

What Aging Wiring services can we provide?

Inspections. Aerospace Innovations (AI) undertakes Aging Wiring inspections on Military, Civilian Transport and civilian General Aviation aircraft. The inspections include the following:

  • a detailed photographic and written record of the aircraft wiring inspected
  • a review of the wiring standards used during aircraft manufacture
  • a review of the service life of the aircraft
  • a review of the wire specifications used
  • a review of wiring husbandry
  • interviews with maintenance staff
  • engineering discussion on the findings
  • conclusions on the integrity of the wiring and maintenance standards employed
  • recommendations to improve the integrity of the wiring systems

Reports are typically 60 to 80 pages in length.  Click here to download a sample of “Table of Contents”.

Training. AI has developed training packages on Aging Wiring tailored for particular aircraft and maintenance regimes for operators and maintainers of aircraft. Training can also be developed and presented as a complete package.  We can develop and deliver training specific to your aircraft and needs.

What are Wiring Systems?

‘Wiring’ refers to all components used in the installation of electrical wire, looms, fibre optic cable and data bus cable throughout the airframe. Components include, but are not limited to, connectors, cable clamps, wire splices and terminal lugs, bonding leads, conduit, earth points, grommets, insulation tape and sleeving, lock and shear wiring, lacing and cable ties, terminal boards, and attaching hardware for the above items.

Services -Aging Wiring Inspections











































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Website Updated
02 May 2012