The Answer Is!

The answers to the professional mechanics test that O’Brien promoted in the last issue as a way to gain much-needed recognition for mechanics as a “professional” career field are provided. And O’Brien says he is available if any one is...


In last month’s article, I floated the idea for a nationally recognized organization to administer a Professional Mechanic’s Examination. When an A&P mechanic successfully passes such a test, a nationally recognized testing organization would recognize that mechanic as achieving professional status within the field of aviation maintenance. Over time if enough A&Ps take and pass the test requirements our profession will gain much-needed recognition as a “professional” career field.

I described the “Professional Mechanic Test” as an open book test that contains at least 100 tough, essay questions. The test would be equally divided between General, Airframe, Powerplant, Electrical, and Regulations with an eight-hour limit from start to finish. I also included in the last article 20 sample test questions on FAA regulations and policy in order to pique one’s curiosity on how hard this test would be. As I promised in that article, here are the answers to those 20 test questions on regulations and policy.

QUESTION 1: What is the major difference in maintenance record entries between PMA and TSO parts?

Answer: A Parts Manufacturer Approval part (PMA) is identical to an individual TC part in every way, so it is considered a direct replacement part for OEM parts. For example, if you change a Piper PA-23-250 nose gear actuator with a PMA nose gear actuator, that action only requires a logbook entry under section 43.9. On the other hand, a Technical Standard Authorization (TSO) part is a generic part, like tires, communication and navigation equipment, seat belts, instruments, etc., that could be used on many different makes and models of aircraft. In many cases installing a TSO part “may” require a Form 337 because installing it would be considered a major alteration of the original type design. For example, installing a new TSO glass cockpit in a Cessna 172 would require a Form 337.

QUESTION 2: What rule talks to remanufactured engines?

Answer: There is no FAR that addresses a “remanufactured engine.” There is only one rule, section 91,421 that talks to rebuilt engine records and allows an engine manufacturer or an agency approved by that manufacturer to zero time the logbooks when the engine is rebuilt to like-new standards. Remanufactured is an industry advertising term that is used to sell rebuilt engines with zero time logbooks.

QUESTION 3: What government agency or administration created the Inspection Authorization and when did it happen?

Answer: The Civil Aeronautic Administration (CAA) created the Inspection Authorization (IA) when it published CAR 24.43-1 on June 17, 1956. So it was the CAA and not the FAA who created the IA almost 50 years ago.

QUESTION 4: How long is a mechanic responsible for the work performed on an aircraft?

Answer: A mechanic is responsible only for the airworthy work he or she performed on an aircraft and only that work, until that work is either performed again, altered, damaged, replaced, or meets its life limit if the part worked on is a life-limited part, or until the work is re-inspected. For the average general aviation aircraft operated under Part 91 the longest length of time a mechanic is under the gun is one year or until the next annual inspection is performed and the mechanic’s work is re-inspected.

QUESTION 5: How long is a mechanic responsible for an inspection to an aircraft?

Answer: After performing an inspection, the mechanic is responsible for the continued airworthiness of the aircraft until the ink in the logbook dries. When a mechanic performs an inspection of an aircraft, that mechanic cannot guarantee the airworthiness of the aircraft six months or even six days into the future when that aircraft is no longer in his care. What a mechanic buys off an aircraft as airworthy after he performs an inspection, is every repair, alteration, STC, Form 337, AD, field approval, and service bulletin back to the date on the airworthiness certificate be that date, six weeks old, six months old, six years old, or 60 years ago. Mechanics, when they perform inspections, buy off all the work performed on that aircraft to the moment the airworthiness statement is made in the logbook. An inspection cannot buy off future airworthiness of the aircraft.

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