FAA CFR Part 91 is an interesting combination of rules for the owner/operator. In the past I saw these only as a list of burdens placed on the owner/operators by the FAA. With just a slight change in viewpoint, Part 91 Subpart E Maintenance, Preventive Maintenance, and Alterations, actually describes privileges and authorities given by the FAA to the aircraft owner/operator. Notice that this Subpart E is included in Part 91 which is written to aircraft owners and operators, not mechanics. It’s important for owner/operators to understand their authority and responsibility when it comes to aircraft maintenance records.

Every now and then I see a maintenance record entry that just makes my hair stand on end. I have no problem with the typical typo, misspelling or poor punctuation.  The incomplete, misleading, or uniformed entries are the ones that get under my skin. Some of these are just laziness on the part of the mechanic, but many are careless and show ignorance of the requirements.

The most recent entry found was from an annual performed on a Cessna 182 two years ago. There was the typical old school rubber stamp stating an Annual inspection had been performed with the blanks built in for dates and signature. Handwritten off to the side of that stamp was a stand alone statement that read “All ADs complied with”.  There was no indication about which ADs required action, what that action was, or when the recurring actions might be due. This creates a significant set of problems for the owner/operator and shows disregard on the part of the maintenance provider for his/her responsibility to the aircraft owner and the FAA.

Well written maintenance records indicate professionalism and likely better overall care of the aircraft. I pay close attention to the form and wording of log entries when performing pre-purchase evaluations to get a feel for the level of care given. In the unfortunate situation when the FAA might be looking through the maintenance records, having well written records makes a very positive impression.

Well written log entries speak volumes, not only about the work performed but also about the person that performed the work. Including part numbers within an entry allows one to find those parts in the future, often much easier than looking it up in the Parts Catalog. A thorough description of the work performed gives an impression of detailed work. Referencing the section and paragraph in the manufacturer’s Service Manual that details the required procedure is even better as it shows the mechanic actually used the process as the FAA requires.

Considering all the reasons to have the best possible maintenance entries, one might presume the mechanic has some major incentive to create some literary gem in the books. As it turns out, writing isn’t the forte of most mechanics and there isn’t much value to the mechanic to make any heroic effort in this regard. The real value is to the aircraft owner/operator.  As it turns out, most of the regulations about making maintenance record entries is included in FAR Part 91, not Part 43.

Maintenance Provider’s Responsibility

§43.9   Content, form, and disposition of maintenance, preventive maintenance, rebuilding, and alteration records (except inspections …….).

  • (a) Maintenance record entries. Except as provided in paragraphs (b) and (c) of this section, each person who maintains, performs preventive maintenance, rebuilds, or alters an aircraft, airframe, aircraft engine, propeller, appliance, or component part shall make an entry in the maintenance record of that equipment containing the following information:
    1.  A description (or reference to data acceptable to the Administrator) of work performed.
    2. The date of completion of the work performed.
    3.  …..
    4.  If the work performed on the aircraft, airframe, aircraft engine, propeller, appliance, or component part has been performed satisfactorily, the signature, certificate number, and kind of certificate held by the person approving the work. The signature constitutes the approval for return to service only for the work performed

FAR 43.9 (a)(1) through (4) is about the only guidance given to maintenance providers for generating maintenance log entries. It clearly states that a maintenance entry should include a description of the work performed or a reference to the acceptable data that details the work performed. “All ADs complied with” at best is a statement of completion but nothing close to a description of the work performed. With this entry we don’t even know if any work was performed at all.  It could be a simple declaration that at some point in the aircraft’s past, ADs were performed and at the moment of this annual, they are all current.

Owner/operator’s Authority

For every writer there should be an editor or at least a proofreader. In the case of a Part 91 operator, that person is the aircraft owner/operator. This may seem odd, but it’s exactly what the FAA has included in FAR Part 91.

§91.405 Maintenance required.

Each owner or operator of an aircraft—

  • (a)…..
  • (b) Shall ensure that maintenance personnel make appropriate entries in the aircraft maintenance records indicating the aircraft has been approved for return to service;

FAR 91.405 (b), the FAA definitively puts the owner in charge of what is in the maintenance records. It may be an uncomfortable position with a mechanic to audit their maintenance entries but the FAA clearly states that is exactly what owners have the authority and responsibility to do.

§91.407   Operation after maintenance, preventive maintenance, rebuilding, or alteration.

  • (a) No person may operate any aircraft that has undergone maintenance, preventive maintenance, rebuilding, or alteration unless…….
    1. ……
    2. The maintenance record entry required by §43.9 or §43.11, as applicable, of this chapter has been made.

FAR 91.407 (a)(2), the airplane may not be flown until the maintenance entry has been made. Since Part 91 is written to owner/operators, not mechanics, this put the burden directly on the owner/operator to get these entries BEFORE flying the airplane.

§91.417   Maintenance records.

  • (a) Except for work performed in accordance with §§91.411 and 91.413, each registered owner or operator shall keep the following records for the periods specified in paragraph (b) of this section:
    1. Records of the maintenance, preventive maintenance, and alteration and records of the 100-hour, annual, progressive, and other required or approved inspections, as appropriate, for each aircraft (including the airframe) and each engine, propeller, rotor, and appliance of an aircraft. The records must include—
        • (i) A description (or reference to data acceptable to the Administrator) of the work performed; and
        • (ii) The date of completion of the work performed; and
        • (iii) The signature, and certificate number of the person approving the aircraft for return to service.
    • 2.  Records containing the following information.
        • (i) ……, (ii) …… ,(iii) ….., (iv) …..
        • (v) The current status of applicable airworthiness directives (AD) and safety directives including, for each, the method of compliance, the AD or safety directive number and revision date. If the AD or safety directive involves recurring action, the time and date when the next action is required.

91.417 (a)(2)(v) clearly states the requirements for documenting compliance with Airworthiness Directives.  When action is taken on an AD, the entry must include the method of compliance (what work was performed) and when it is due again if it contains any recurring elements. Obviously, “All ADs complied with” doesn’t come anywhere close to meeting any of the FAA requirements.

Most owner/operators subcontract the FAA Airworthiness Directive research to their Authorized Inspector. This is an accepted practice but doesn’t relieve the owner/operator of the responsibility to ensure that complete and proper entries are made.

One may think that proofreading a mechanic’s entries is problematic because one may not have all the information needed to understand what should be documented. As the person most interested in having clear and useful maintenance records, the owner/operator is the perfect person for the job. Entries must be accurate and understandable with appropriate detail. If the reader can’t understand what was done, then the description isn’t sufficient.

Another difficulty is telling one’s mechanic that an entry needs to be rewritten. This may be awkward for some. No one wants to alienate their mechanic so tread lightly here. The benefits of having strong historical maintenance documentation is of utmost importance and well worth the effort.

Well written maintenance history gives part numbers, repetitive events (scheduled and unscheduled) and previous solutions to problems. They show possible future owners how well the plane has been maintained which enhances resale value. The FAA sees good record keeping as a sign of an owner that’s involved and interested in safety.  Maintenance records are of great value to every owner and it is in one’s personal best interest to ensure entries are proper and complete.