Signing My Life Away

The power behind the certificate


Wandering around the United States explaining and defending the Federal Aviation Regulations (FAR) at IA seminars, mechanics put me in touch with the real world of aviation.

When I bring up Part 65 and explain what an A&P mechanic can and cannot do, most mechanics are surprised to learn that the real power in the FAA mechanic certificate card is not just the right to work on airframes and powerplants, it's something more. It grants the holder the authority to legally sign a logbook!

In truth a mechanic makes only two decisions when he signs a logbook after performing maintenance or an inspection. Either the aircraft or part is airworthy or it is not. This yes/no process is known in the jargon of the maintenance profession as "signing my life away!"

Is it or is it not airworthy?


Before we go any further we must define the term "airworthy." When an aircraft or one of its component parts meets its type design or properly altered condition and is in a condition for safe operation it is airworthy. Type design is what part the aircraft was built to as described in the aircraft, engine, or propeller specifications. An aircraft can only be properly altered in three ways. Either by an STC, field approval, or by an AD. Condition for safe operation is when a mechanic checks for wear using the aircraft maintenance manual as a guide.

Along with the airworthy determination there are two kinds of entries a mechanic can make in a logbook. He can sign off maintenance that he performed and he can sign off an inspection. These two sign-offs: maintenance under section 43.9 and inspection under section 43.11 look the same, but are different. The definition of the word "maintenance" in Part 1 includes inspection, but the word "inspection" does not include maintenance. A fast explanation - "When you perform maintenance you get your hands dirty, when you perform an inspection you don't."

What I would like to discuss are logbook entries that are used for Part 91 aircraft only. Part 121 and 135 operators are required to make maintenance entries in accordance with their operating manual.

When you perform maintenance on an aircraft the logbook entry required by section 43.9 requires the following information.

1. A description of reference to data acceptable to the administrator of the work performed;

2. The date the work was completed;

3. The person's name performing the work;

4. The signature, certificate number, and kind of certificate (A&P or A or P) held by the person approving the work.

OK, it looks straightforward, but let me explain a couple of items. First is acceptable data. Acceptable data is basically information, techniques, and practices on how to perform the work. It can be manufacturer's maintenance manuals, bulletins, AC 43.13-1B, and AC 43.13-2A. The data can be used to perform minor repairs and alterations but not major repairs and alterations; that requires approved data.

The second item is including the name of the person performing the work. Many mechanics allow the owner to help with the annual or 100-hour but never put in the owner's name. This is not only a mistake but you are missing an opportunity. It's a mistake because it is a FAR requirement to include the name of the individual who did the work under your supervision in the logbook. The missed opportunity happens because you missed the chance to get quality workmanship out of the owner/helper.

The third item is a bit subtle. If you notice the rule does not include a formal approval for return to service statement. How so? This is because the rest of section 43.9 (a)(4) states that the mechanic's signature, certificate number, and kind of certificate held constitutes the approval for return to service but only for the work performed. It is important that a mechanic understands that every maintenance entry he makes should be concise, accurate, and complete because the work he describes is what he is held responsible for.

Most mechanics are not sure how long they're held responsible when they sign off a maintenance entry. So write this one down. When a mechanic performs a maintenance task, such as fixing an air stair door on a Beech King Air, that mechanic is responsible only for that work accomplished and signed off, until the same work has been altered, performed again, removed, damaged, meets its life limit, or until it is reinspected. On the average, the longest amount of time a Part 91 mechanic is held responsible is approximately one year.

Inspection entries

There are over a thousand different inspections you can perform on an GA aircraft or a part thereof. You have the annual, 100-hour, 50-hour and progressive inspections, plus hard landings, lightning strikes, corrosion inspections, inspections required by ADs, and manufacturer's inspections. They all must be signed off in the logbook in accordance with FAR 43.11. The rule requires the following information: date and total time; type of the inspection performed and a brief description of the extent of the inspection; and signature, certificate number, and kind of certificate held by the person approving or disapproving the aircraft or portions thereof, for return to service.

The definition for total time in service in Part 1 says the time from the moment the aircraft leaves the surface of the earth to the time it returns to land. Total time can be recorded with Hobbs meter, tack, or by each flight time in the logbook.

Next look at the word "aircraft." The word aircraft in Part 1 means a device that is intended to be used for flight in the air. So when the word "aircraft" is used in an inspection entry it means that you inspected every thing that makes up the aircraft. But your overall responsibility and accountability will depend on the kind or type of inspection you performed.

A good rule of thumb to follow is any time you perform a special inspection such as a hard landing or corrosion inspection check if any AD or recurrent AD is due even though a check for AD compliance is not specially called out.

Again, using an annual inspection as an example, how long does the FAA hold you responsible for the continued airworthiness of the aircraft after you signed the annual off? The correct answer is until the ink on the logbook page, dries! This almost sounds like a get out of jail free card! I can hear the mechanic saying: "Send me those annuals!"

But it is true. The FAA does not hold a mechanic responsible for the continued airworthiness of the aircraft after an inspection for two reasons. First, section 91.403(a) states that the owner or operator is primarily responsible for the airworthiness. Second, the FAA realizes it is not fair to hold a mechanic responsible when it's no longer in the mechanic's care.

So if a mechanic performs maintenance and is held responsible for that work for one year by the FAA; then how long is a mechanic held responsible and accountable for an annual? Answer: When a mechanic signs off on an annual inspection that mechanic is saying to the world that he reinspected every bit of maintenance that was performed. That includes, major and minor repairs or alterations, service bulletins, STC, Field Approvals, every AD and recurrent AD, all the way back to the date on the aircraft's Airworthiness Certificate. Another way of looking at it: when a mechanic performs maintenance he buys the future, when he performs an inspection he buys off the past. Either way, you are signing your life away

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