Some documents, as Rodney Dangerfield might say, ‘’’…get no
respect.” That is of course, until the mud hits the fan. So it is with the supposedly
lowly tear-down report. Day in and day out we routinely check for the presence
of these documents, checkoff a box on our receiving checklist, then add them to
the scan/file pile. Done. There are situations however, when those reports are
going to demand a lot of attention, which is the focus of this blog.
Tear-down reports may go by many names such as ‘Work Shop
Reports’, ‘Shop Findings’, and ‘Work Order’, among others. Essentially they are
a summary of the work performed, parts replaced, the reason those parts were
replaced, and other pertinent data. Generally the regulations of the respective
country’s Civil Aviation Authority require such information be recorded when
aircraft components are being repaired and overhauled. The tear-down report
accompanies the Airworthiness Release Certificate such as an EASA Form 1 or FAA
Many times preliminary tear-down reports are created in
order to facilitate the customer quoting process. For example, a maintenance
shop receives a component for overhaul but first the customer wants a quote of
what the price will be before authorizing the commencement of work.
In this blog we’ll review the following:
1) Reliability: Identifying trends
in failed parts
2) Establishing warranty claims
3) Does the stated work and parts
replaced align with the price charged?
Sidebar Fun Fact: Rodney Dangerfield, whose name at birth
was Jacob Cohen, took on his stage name based on a cowboy character in a Jack
Benny radio show.
Identifying trends in failed parts
I recently attended the AMC/AEEC (Avionics Maintenance
Conference/Airlines Electronic Engineering Committee) Conference; more on them
later1. The AMC for many
years has been a platform for airlines to collectively express their concerns
with certain Avionics systems and components. Their questions and concerns are
submitted ahead of the conference so as to give the respective OEM and/or
airframer the opportunity to respond during the conference. The entire process
is quite orderly and organized, and typically well researched. I estimated there
were about 600 attendees from around the world made up mostly of Avionics
Engineers, Customer Support Representatives, and Avionics Maintenance Managers,
What follows is a classic use of tear-down reports which
were analyzed in order to address reliability problems. This is a redacted
posting from one of the discussion items:
analysis of 124 landing light assemblies’ teardown
reports was accomplished over the period xx/xx/xx to xx/xx/xx with the top
issues reported as lens cracked/broken (77%), wire harness cracked/broken
(77%), and lamp harness open (61%). (Airline) xxx and (OEM) xxx reviewed a
corrective action plan to improve the lamp harness with a service loop
(bulletin). (Airline) xxx has just implemented this so it’s too early see if
this action will correct the harness issues.”
removal rates within an ATA chapter exceed a specified threshold, alerts are generated
and issued to the airline maintenance organization. Investigative actions
typically include analysis of tear-down reports as just illustrated.
Establishing warranty claims
for components that have undergone maintenance typically extend to the work
performed and the parts replaced at the last visit. When there is a premature
removal from the aircraft, the question arises by the operator if the part is
under warranty, and if so, to return the part for a warranty claim to the
maintenance shop. The maintenance shop will have to analyze two questions to establish
whether they will honor a warranty claim:
the removal occur during the covered period of the warranty?
something fail that was ‘covered’ (previous task performed, previous parts
the Tear-down report. A simple example: The part was removed from the aircraft
after 2 months since the last shop visit. At the last shop visit the failure was confirmed by the removal and
replacement of transistor Q1. The unit passed all subsequent tests and was
returned to service. This time however,
the failure is confirmed by the removal and replacement of transistor Q2, which
was not touched the last time since it was working just fine. Will the warranty
be honored? To be clear, I don’t wish to get into a side discussion about
warranties, but it should be evident that referring to the details contained in
tear-down reports help establish grounds for warranty claims.
Does the stated work and parts
replaced align with the price charged?
just charged your customer a hefty price for an overhaul. You can expect that tear-down
report to receive quite a bit of attention. Hopefully the work performed and parts
replaced align with the price you charged or you can expect an ear-full.
sidebar: Rodney Dangerfield famous one-liners:
bought a new Japanese car. I turned on the radio... I don't understand a word
bought a perfect second car... a tow truck."
a dog I got, he found out we look alike, so he killed himself."
I was a kid my parents moved a lot, but I always found them."
looked up my family tree and found three dogs using it."
my old man I got no respect. I asked him, 'How can I get my kite in
the air?' He told me to run off a cliff."
1AMC/AEEC background: From their
respective ARINC website:
AMC: The AMC is an air transport industry activity organized by ARINC Industry
Activities. The objectives of AMC are to promote reliability and reduced
operating cost in air transport avionics by improving maintenance and support
techniques through the exchange of technical information. AMC consists of representatives from the technical
leadership of the air transport avionics maintenance community. The voting
membership of AMC consists of the representatives of commercial air transport
AEEC: The Airlines Electronic Engineering Committee (AEEC) creates value for
airlines and the aviation industry by developing engineering standards and
technical solutions for avionics, networks, and cabin systems that foster
increased efficiency and reduced life cycle costs for the aviation community.
been my experience that these groups over the years have quietly, continuously,
and collaboratively made significant contributions to increased reliability,
standardization, and safety.