Logbook Research Part 2

Logbook Research It's not just an AD search any more. Part 2 of 2 By Joe Hertzler This is the second in a two-part series on the process of evaluating the maintenance records of an aircraft. The purpose of such an evaluation is to...


Joe HertzlerThis is the second in a two-part series on the process of evaluating the maintenance records of an aircraft. The purpose of such an evaluation is to establish the current maintenance and inspection status as well as extract information from the records that may impact the value of the aircraft.

In our last issue we discussed how to organize the records in preparation for research including looking for gaps in the records, establishing the current times and cycles, and creating the list of required inspection and maintenance items. This issue will discuss the actual review and research process.

Logbook research process flow

To begin, you will need to have the requirements list you created close at hand so that you can write in (or type in) the complied dates and times as they are found in the records.

Each airframe, engine, and propeller is considered a "Class I Product" (Ref CFR 21.321, (b)), and as such, each has its own sub-set of records (i.e. Airframe, Engine and Propeller logbooks). We recommend that each sub-set be reviewed one at a time.

One of the primary objectives is to identify when each of the scheduled inspection and maintenance items were last accomplished and when they are due next. It is for this reason that we begin at the most recent entry. Read each maintenance entry located in the logbook beginning with the most recent entry and work backward to the original airworthiness certification statement. The idea is to find and capture the most recent occurrence of each scheduled maintenance requirement. For example, if the Phase inspection is due each 200 hours of operation, the most recent entry will need to have been accomplished within the last 200 hours.

As you make your way though the records, read each entry looking for the following three things: Items that are part of the scheduled maintenance requirements, entries that indicate the aircraft was damaged (i.e. propellers replaced at odd times, flight controls replaced, skins replaced, hard landing inspection, etc.), or any entry that references an FAA Form 337 for Major Repair, and entries that include incorporation of a Supplemental Type Certificate (STC), or any other reference to an FAA Form 337 for Major Alteration.

Note: FAA Certificated Repair Stations aren't required to complete FAA Form 337 for Major Repairs and oftentimes don't when the aircraft was damaged due to an accident or incident (Ref 14 CFR Part 43 Appendix B (b)).

Requirements comparison

The logbook research process is really just a comparison of the hard copy maintenance records to the maintenance requirements spelled out by the inspection program for the aircraft and the FAA. As you read through the logbook and find scheduled items that have been accomplished, record the date, time, and cycles (as applicable) for each scheduled item (inspection, replacement, lubrication, etc.) on your list of requirements.

As you continue your way back through the logbook you may get to the point where all of the scheduled maintenance items have been accounted for and the only items you are looking for are Airworthiness Directive and Service Bulletin compliance and evidence of damage or modifications. I also like to make note of maintenance that seems to be repeating itself, but is not scheduled.

If you have made it back through the logs once and have not been able to answer all of the scheduled maintenance questions you will need to make a second and possibly a third pass to try and locate the items. Often you will find a date and time where you think an item was accomplished, but the entry just doesn't make it clear. Make notes so that the owner or buyer can call and check on it later.

Once completed, your list of inspection and maintenance requirements should have a date and time at which it was last accomplished and thus will reflect the current status of each required maintenance item. Using that list, you can discuss with the owner or prospective purchaser the items not reflected in the records. It is important to understand that when items are "not reflected in the records" it doesn't necessarily mean that they have not been accomplished. It simply means that the records you reviewed do not contain evidence of the maintenance. "What's the difference?" Well, someone may have done the work and not properly recorded it in the records or the entry may have been written on a stick-in logbook entry and placed in a file at the owner's office. Presenting the items to your customer as "records deficiencies" will go a long way in bringing resolution, even when resolution means doing or re-doing the work.

What is an acceptable logbook entry?


For a logbook entry to be acceptable, it must include the date, description of work, signature, and certificate number of the person approving the work, (Ref 14 CFR Part 43.9). Inspection entries must also include the aircraft/engine/propeller time in service (Ref 14 CFR Part 43.11). Each Airworthiness Directive signed off in the maintenance records must include the AD number, the date the AD became effective, the method used to comply with the AD, and, if the AD is recurring, the next time/date/cycles that the AD will be due.

Damage history


When reading through the logbooks, records of possible damage history may not jump out at you. When accidents result in damage to an aircraft, the owner will always try to minimize the damage thus minimizing the impact on the aircraft's value. On the other hand, the buyer or the buyer's agent will always be hyper-sensitive to anything that may indicate the aircraft's value may be in question. Record the date and aircraft time of each Major Repair or possible damage record on a separate sheet of paper labeled "Damage History." You are safest to simply present any suspect or questionable entries to your customer for evaluation.

Major modifications


Major modifications come in basically two forms: STC's and Field Approved Modifications. The difference is that STC's are approved through the engineering side of the FAA by the local Aircraft Certification Office, either as a one-time STC or as an STC to be used on multiple aircraft. A Field Approved Modification, although harder to find these days, is approved by the maintenance side of the FAA, the Flight Standards District Office. Either modification is completely acceptable and legal and must be documented using an FAA Form 337. One thing to look for in a Major Modification is a section called "Instructions for Continued Airworthiness" or "ICA's". The ICA's will be included in the text on Field Approved FAA Form 337s and often come under separate cover when associated with an STC. The ICA is where you will find any new maintenance requirements that come with the modification to the aircraft. Older modifications that were field approved generally won't include ICA's. It wasn't until about 1998 that the FAA began requiring ICA's as a part of the field approval process. Here is the stickler, many owners aren't aware of the new inspection requirements that come with ICA's and haven't required maintenance providers to perform the tasks. In these cases, these items need to be brought up to speed.

Another item to look for in your records evaluation is re-upholstery of aircraft interior. It is a requirement that the materials that make up the aircraft interior pass certain burn certification tests. The exact test required is dependent upon the operation of the aircraft and/or the size of the aircraft. The maintenance record entry should state that the interior components meet the requirements of the appropriate regulations (i.e. 14 CFR Part 25.853). In addition, a complete interior certification package should be with the aircraft maintenance records including all of the burn certification documentation for each piece of material used during the installation. Certifications are required for any new cabinet materials and wood finishing chemicals. Typically, samples, or "coupons" of the completed materials are sent for certification and the certification documents (8110-3s) will indicate what was tested and to what specification.

Incomplete or inadequate interior refurbishment documentation can be a big hole in the logbook. When the new owner attempts to place his aircraft on a Air Carrier Certificate (14 CFR Part 135), he may be required to rework the interior to bring it up to speed.

The end result of a complete maintenance records evaluation is a clear picture of any holes in the maintenance records, the current modification status of the aircraft, and any evidence of damage to the aircraft. Once any deficiencies are straightened out, the objective is then to keep the records accurate and complete in order to ensure the value of the aircraft. AMT

Joe Hertzler is the president of AVTRAK Inc., an Aurora, CO-based company. Joe is an Airframe and Powerplant Mechanic with Inspection Authorization and also a Private Pilot.

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