Anti-PMA Rhetoric is Wrong; PMA Parts are Valid,
By Jason Dickstein
The FAA has issued a special bulletin reminding
the industry that PMA parts are perfectly valid for use, and
that competitors’ rhetoric questioning FAA-approved PMA parts is
contrary to FAA technical findings.
The FAA announcement came in the form of a
Special Airworththiness Information Bulletin, or SAIB. The FAA
uses SAIB’s as a mechanism for communicating safety information
that is valuable, but that falls short of the requirement for
issuing an Airworthiness Directive. SAIB’s are meant to alert,
educate, and make recommendations to the aviation community.
Normally, SAIB’s are issued about specific technical concerns
that the FAA has identified.
It is highly unusual for the FAA to answer an
industry marketing campaign with a SAIB, but that is what we
seem to have here in the August 8th SAIB addressing PMA parts.
Various manufacturers have made a variety of commercial
statements designed to undermine public confidence on PMA parts.
The FAA specifically notes that “some engine manufacturers
responded to the FAA’s approval of PMA and STC for parts
involving their type design engine models by telling customers
that support of their products could be limited if such parts
are installed.” The FAA explains that some manufacturers “have
included language in the FAA-approved airworthiness limitation
section (ALS) of their engine instructions for continued
airworthiness (ICA) stating that the ICA was developed only for
use with their parts.”
By issuing this SAIB, the FAA has said “enough
is enough.” The SAIB makes it clear that when the FAA approves a
PMA part, they expect that the industry will treat that approval
with the respect that a decision of the FAA deserves, and that
furthermore such parts are entitled to the full recognition of
the FAA’s approval, and it is not up to the engine manufacturer
to say that installation of a PMA part is wrong or invalid.
The FAA draws four important conclusions in
PMA Parts are Valid Replacement Parts
FAA-approved TC/PC holder, PMA, and STC parts
are interchangeable within the certificated product since they
are approved only after a full demonstration of compliance to
the applicable requirements of Title 14 of the Code of Federal
Regulations (14 CFR). A PMA or STC part, when FAA-approved for
installation on a certificated product, is a valid replacement
part to the TC/PC holder part according to 14 CFR.
Installation of PMA Parts Does Not Change
the Life Limits for the Other Parts In the Assembly
Unless stated otherwise as a limitation to an
STC, the FAA has determined and the applicant has shown that
FAA-approved life limits established for the TC/PC holder parts
remain unchanged for those TC/PC holder parts when PMA or STC
parts are installed elsewhere within the product. For example,
the life limit for a TC/PC holder disk is unchanged and remains
in effect when PMA blades are installed in that disk.
A PMA Holder Has Shown that the ICA's are still
Valid OR Has Provided a Supplemental ICA for any Differences
The FAA approves the content of an ALS and ICA based upon its
review of the substantiating data provided by an applicant.
Applicants for PMA or STC parts are required to assess the ICA
requirements. A PMA or STC applicant either shows and states
that the product’s ICA are still valid with their part installed
or provides a supplemental ICA for any differences.
The full text of the FAA’s Special Airworthiness Information
Bulletin is available for review:
SAIB 2008-08-08 (PDF)