A couple of friends recently experienced incidences in their planes that initiated investigations involving the FAA. The incidents were not caused by some violation of the regulations, and no one was physically hurt. What did happen was that the FAA requested and obtained the maintenance records of the plane. This is a standard part of their job with the expressed intent to determine if the airplanes were legal and airworthy at the time of the event. As it turns out, everything in the records you turn over are fair game for FAA review. They won’t limit their reading to just the last annual and what’s happened since then. The infraction that invites this revealing look into one’s past might be as simple as a flat tire resulting in a minor runway excursion. The education can be shocking.

All records turned over to the FAA are thoroughly read and studied. Every rock is turned over and closet door opened. Any previous overfly of any Annual inspection date, AD time limit, IFR 24 month recertification, or ELT annual test is noted. Of course, any of those infractions may be included in a letter to you notifying you of the regulatory violation.

I’m not an expert in what options the FAA have open to them in such situations. Your attitude and reaction during the ensuing investigation may affect how intensely they pursue any action. Fortunately, there’s some very simple and free software that can help automate much of the needed reminders. All one needs is a computer, access to a spreadsheet, and the desire to not fly past an FAA requirement.

Spreadsheet Building

The first step in the process is to determine what should be tracked. FAA CFR 91.417 (a)(2) Maintenance records, requires the owner/operator to keep records tracking the total time in service of the airframe, each engine, each propeller and all life limited parts. It’s important to note that this requirement is contained in Part 91 General Operating and Flight Rules and not Part 43 Maintenance. The regulation applies to the owner/operator, not the maintenance provider, so it must be placed in the regulations that the owner/operators read. All that to say putting all the hour meters, total times and times since overhaul of the main components in the top section of the spreadsheet makes good sense.

I’m not a spreadsheet guru, so building this for my plane involved lots of Googling for ways to properly create formulas for date tracking and such. I started with basic aircraft time calculations in the header. A block for the tachometer or hour meter reading, whichever is used to track maintenance events, is the basis for all things related to hourly compliance. The norm is to reference the recorder that operates the slowest. A mechanical recording tachometer will usually record time about 10% slower than the Hobbs meter, so the tach is the obvious choice.

The main body of the spreadsheet might include a line for each item being tracked. There’s no best order to put these, so whatever floats your boat works. I typically choose an order that puts the most frequently addressed events at the top. Alphabetical could work just as well.

The most common items to track are annual inspection, ELT inspection CFR 91.207(d), ELT battery due date, transponder/altimeter/encoder recertification, aircraft registration, oxygen bottle hydrostatic DOT check, VOR 30 day IFR check, airworthiness directives and any airworthiness limitation items that might apply to your plane. These would be a good starting point for government required items.

While in the spreadsheet mode, you might as well add any optional items to the list. These could include oil changes, nav data updates, service bulletins, biennial flight review, or anything else that comes to mind. It’s your spreadsheet to put on it what’s important to you.

The columns should have titles that make sense to you. The first column could be the description of the action to be taken or the part to be replaced. On my spreadsheet I labeled this “Service Description”. Nothing high tech, just enough so you will know what it means.

The second column might be the source of the items requirement or the document detailing what must be performed. Lycoming SB 480 describes their recommendation for oil change time. FAA CFR 91.207(d) would be the reference for the annual ELT tests. CFR 91.411 & 91.413 would be the 24 month transponder/altimeter/encoder recertification checks. Having these references are handy when explaining to maintenance providers precisely what work needs to be performed.

It’s always good to have the recurring interval plainly stated for each item. Being reminded of how frequently an event occurs is helpful in planning as well. There will be several that have flight time compliance as well as calendar compliance requirements, so be sure to track both. Airworthiness directives are notorious in this regard.

While on the subject of Airworthiness Directives, it’s important to note that many of these have multiple compliance events. The twin Cessna exhaust AD has at least five recurring inspections and parts replacements which have independent cycles, and must all be tracked. Each should have a unique maintenance record sign off as well.

It’s good to have a column that shows when each item was last complied with. There should obviously be a column that displays when each item is next due based on flight time or calendar time. If that’s included, then the next due column would use a formula in each block to calculate the entry based on the interval column and the last complied with column.

The most useful of the entire spreadsheet is a time remaining column. These entries display the difference between the next due time and the current date or tach time. Creating a color code so the ones within some predetermined percentage of due time will turn red is very helpful.

I once created a similar spreadsheet to track all the recurring items on a turbine twin for a CFR Part 135 charter operator. The massive size required dividing the spreadsheet into multiple pages with categories and subcategories. I was able to extract the items data with the shortest calendar due time and flight due time and duplicate them on a simple front page. This allowed determination of airworthiness status with just a glance. The aircraft’s time recorder reading would be on the same page and updates the flight due times, ensuring all is current. The date due times would automatically update each time the spreadsheet was opened.

Having all this great information is only valuable if it’s available when it’s most convenient. That time is typically when one is sitting in the plane needing to ensure the ensuing flight can be completed within the next required due times. The easiest solution is to choose a cloud based spreadsheet. This allows opening, updating and reviewing from any device available: smart phone, tablet or laptop computer. Comes in handy for FAA check rides or ramp checks, too.


The ultimate concept is to be absolutely certain that at any given moment, every owner/operator can easily know the status of all required events on the aircraft. All it takes is a flat tire resulting in a little runway excursion to bring on that FAA investigation into your sordid past. Don’t wait until it’s too late to discover what’s out of order. Let’s be proactive and get things in order so we can have confidence in the aircraft’s legal status.

Copyright © Paul New 2017. All rights reserved.