Aircraft Maintenance Editing and Proofreading Services

Douglas Aircraft used two different names for one part, and the National Transportation Safety Board asked the government to have the manufacturer reconcile the two names. The Board concluded that "because Douglas uses two different terms ('firing lanyard' and 'inflation cable') for the same part in its MD-80 and DC-9 maintenance manuals, the manual remains potentially confusing."¹ Recommendation A-96-139 then asked the FAA to require Douglas to review and amend both manuals.¹ The stated purpose was that the terminology used in graphics and instructions for the installation and removal of evacuation slides be "clear and consistent."¹

What the regulations say about the manual

Under 14 CFR 43.13(a), each person performing maintenance must use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness.² The same sentence allows "other methods, techniques, and practices acceptable to the Administrator, except as noted in § 43.16."² Paragraph (c) adds that for the holder of an air carrier operating certificate, the methods in that holder's own maintenance manual "constitute acceptable means of compliance with this section."² A mechanic therefore works from a written procedure, and which document supplies it depends on who holds the certificate.

For a transport category airplane certificated under Part 25, Appendix H sets out what the Instructions for Continued Airworthiness must contain.³ It requires that "The contents of the manual or manuals must be prepared in the English language."³ It requires that "The format of the manual or manuals must provide for a practical arrangement."³ The required contents include troubleshooting information "describing probable malfunctions, how to recognize those malfunctions, and the remedial action for those malfunctions."³

What the accident record says about these documents

In the Air Midwest 5481 investigation, the Board looked at a work card and at the manual the card named. The manual "did not contain a stand-alone procedure for checking elevator cable tension, as called for on the D6 work card."⁴ The card's first step called for a temperature reading that determined the tension values for the cables, and the Board noted that the card "did not specify how to take the temperature."⁴ A step named a measurement without naming a method.

The FAA's account of a 1991 accident describes a different failure of the same kind. Work cards carried "no entries" that would have told the third shift a second shift had already begun work on the horizontal stabilizer deice boots.⁵ One written record did exist. "The second shift work on the accident airplane was indicated on the second shift inspector's written turnover sheet; however, the incoming third shift inspector reviewed the sheet before the entry was made."⁵ Air carriers are required to hold procedures for work "not completed as a result of shift changes or similar work interruptions."⁶

Auditors report the same pattern away from accidents

The Department of Transportation's Inspector General reported in 2010 on FAA oversight of American Airlines' maintenance programs. According to American officials, the report says, the carrier's engineers verbally requested in 2006 that quality assurance representatives inspect the Boeing 757's windshield heat components as the airplanes came in for maintenance.⁷ The auditors wrote that "the engineers did not document the request or inspection results, so we were unable to verify that the inspections were performed."⁷ An instruction that was never written down could not afterward be shown to have been carried out.

A 2013 audit of repair station oversight found employees who "did not complete work orders to document technical data they used during repairs."⁸ The same sentence lists incorrect employee stamps used to document completion of work steps, and work steps signed off by employees not authorized to complete them.⁸ In the same sample, officials could not produce training documentation for the tasks required in 45 of 119 work orders.⁸

An FAA Office of Aerospace Medicine proceedings report records an industry participant's observation about where technical data is held.⁹ "Technical data are rarely all in one place."⁹ Technicians "must assimilate information from multiple parts of a manual and even multiple manuals."⁹

What an editor reads, and what stays with the certificate holder

We make no airworthiness determination, and we do not approve anything for return to service. We do not judge whether a task was performed correctly, or whether a reference is acceptable data. Those acts belong to the people the regulations authorize to perform them.

What comes to us is the written material around the work. It includes maintenance procedures and task cards, quality and training manuals, and service bulletins. It also includes technical publications prepared for operators, and the internal instructions describing how a record entry is composed.

In that material we look for one name used for one part across the task card, the illustrated parts list, and the manual section. We look for a reference that names the procedure a reader needs, and not a number on its own. We look for steps set down in the order the client's own procedure states, and an abbreviation given in full at its first appearance. We look for a document control number and a revision date that match from the cover to the footer. Every document a client sends us is treated in confidence.

Appendix H tells a Part 25 manufacturer to prepare its instructions in English and to arrange them practically.³ Two questions recur in the findings above. The first is whether the writing was clear enough to act on. The second is whether it was written down at all.