What Is A Proper Entry In Aircraft Records?

Content and form of an aircraft maintenance record entry are dictated in the Federal Aviation Regulations and described in the FAA Advisory Circulars.

FAR 91.405 states maintenance personnel shall make appropriate entries in the maintenance records indicating the aircraft has been approved for return to service.
FAR 91.417 requires aircraft records to contain:
A description of the work performed
The date of completion of the work performed
Signature & certificate number of the person approving the aircraft for return to service
Total time in service of the airframe, each engine, propeller and rotor
Current status of all life limited parts
Time since last overhaul of all components required to be overhauled on a time basis
Current inspection status
Current status of Airworthiness Directives
Form 337 documenting major repairs & major alterations
AC 43.9C states the content should be such that a person unfamiliar with the work performed can understand what was done and the methods and procedures used to perform the work. AC 43.9C also allows for the entry to make reference to other data to avert the necessity of lengthy entries to describe complex, protracted methods, processes and procedures.

As usual, the regulations and guidance are subject to individual interpretation. The use of the word “appropriate” in FAR 91.405 only indicates a “suitable or fitting” entry. AC 43.9C provides helpful guidance in telling us an entry should contain enough detailed information that for someone unfamiliar with the work performed, the person reading the entry would be able to understand what was accomplished and how it was accomplished.

Unfortunately, the guidance in AC 43.9C doesn’t specify to include “why” the work was accomplished to be incorporated in the entry. Entries made to document the compliance of an inspection task are usually understood or assumed to have been created as the result of the inspection being due and complied with. Entries for component replacement and/or discrepancy correction are different. For someone not familiar with the aircraft, knowing the “why” a component was replaced can be very important. Was the component replaced due to a time controlled event or due to a discrepancy/failure? Was the component installed “repaired”, “overhauled” or “time continued/as removed”? What specifically was the discrepancy; what was being corrected? Without this information, a technician working a future discrepancy on the same system/component would have no way of knowing if there was a recurring problem or a new, unrelated event. It could also save additional costs in time and money of an unnecessary component replacement and/or retracing the same steps someone else already accomplished.

The maintenance records entry should contain a reference to what instructions, guidance or directives were used so there is no question the methods, processes and procedures employed were based on FAA Approved Data. Any back up or referenced documentation must be maintained in the aircraft records files as long as they remain relevant to the aircraft.

Many aircraft have separate sections in the log books or even a separate log book for the recording of technical bulletins. A properly maintained set of aircraft records will have technical bulletins recorded in the general maintenance log entries AND also recorded in the separate technical bulletin area. A well maintained separate technical bulletin area allows for quicker, more accurate records review to determine the bulletin status of the aircraft. The status of any bulletin applicable to your airframe, engine or component thereof should be recorded in the records as complied with or not applicable; no entry will indicate the bulletin is not complied with and may possibly be applicable to this aircraft. Bulletins that are considered “optional” may be listed with no further information; this would indicate awareness of the content, with no further action taken. Not listing an “optional” bulletin would also indicate no action has been taken.

FAR 91.417(a)(2)(v) states the requirement to keep a current status of applicable Airworthiness Directives and the method of compliance with the directive. Even though the regulation only requires the status of “applicable” Airworthiness Directives, inclusion of the status of “non-applicable” ADs in the records give a more complete picture of the AD status of the aircraft. An AD that could possibly be applicable to an airframe or engine by Serial Number or by way of an option, Service Bulletin or STC, but is not, should be entered in the records and signed off as “Not Applicable” or “N/A”, including an explanation of why the directive is not applicable. If such an entry is not made, even though not required, it will force the next person performing a records review to research each Airworthiness Directive not signed off to determine if it is applicable or not. FAR 91.417(a)(2)(v) also states if a directive involves a recurring action, the entry must include the time and/or date the next action is required.

Remember, when making an entry in your aircraft records, you may not be the next one reading these records. Include in your entries all the information required to describe who, what, when, where and why an action was taken. Always complete your entry with your release statement, signature, certificate number, what type of certificate it is and indicate the date, aircraft/engine time and cycles the work was completed and approved for return to service. There is no restriction to supplying more information than is required or considered the bare minimum by the FARs.

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