There have been countless articles written about the Annual Inspection, including a couple from me. It seems there is no end to differing viewpoints on how these events should go or what they should cost or why they should be done. It occurred to me that there are three very different entities involved, each with its own agenda and priorities. I’d like to explore these three participants and see if I can help manage your annual inspection expectations.

To be clear, the scope of this article is limited to single engine piston aircraft operated under the Code of Federal Regulations Title 14, chapter 1 subchapter F part 91 not for hire and not using a progressive inspection program.


The first and boldest participant is the FAA. They probably aren’t physically present during the annual inspection, but their presence is certainly felt. The FAA is the primary instigator being that Part 91.409(a) lays down the law requiring the aircraft must endure an annual inspection every twelve calendar months.

The FAA requires an annual inspection to determine if the aircraft is airworthy. That may sound like a lofty goal based on all the discussions and debates you’ve likely read. The FAA definition of Airworthy is found in Title 14, chapter 1, subchapter A, Part 3 and states “Airworthy means the aircraft conforms to its type design and is in a condition for safe operation”. This is a very low set bar once you get past all the fluff that’s been added by industry and folklore.

For the purpose of Airworthy, conformity means that the airplane has all the proper parts installed that the manufacturer designed it to have. Much of this is detailed in the FAA Type Certificate Data Sheets. In a nutshell, this means it has the correct make and model engine, propeller, wheels, magnetos, fuel pump, starter, etc. installed. It does allow for changes from original in the form of a Supplemental Type Certificate like adding Tornado Alley Turbo Normalized system or a Kelly air conditioning system.

It is interesting to note that the definition of Airworthy has no past or future element. It doesn’t care what the plane’s condition was yesterday, last year, tomorrow or next year. When an annual inspection is signed by the inspector, it means that the airplane conforms and is safe at that moment only. It doesn’t mean that the plane is safe to fly for the next 12 months.

In Appendix D of Part 43, the FAA has published the minimum scope and detail for an annual inspection. This very short and somewhat vague list is all that the FAA requires be done during an annual inspection. It does not include any servicing or repairs of any kind, no oil change, no lubrication, no required overhauls, no required service bulletins, no manufacturer recommended items at all. Appendix D is far more interesting in what it doesn’t include than what it does.

The FAA also requires that at the time the inspection is signed off, all FAA Airworthiness Directives (AD) are current, and all Airworthiness Limitations (AL) are current. Since the annual has no future requirements, an AD could come due the next day but would not be a required part of the annual.

As far as the FAA is concerned, one only needs to comply with the applicable regulatory elements. All of those elements are written and clear. No FAA employee can add any personal subjective element to the process. This makes the FAA’s part of the annual inspection very tidy and easily quantifiable.

The Inspector

The person you contract to perform this once per year event must follow the applicable regulations that include Appendix D of Part 43, and the applicable portions of Part 43.11, 43.15 and 43.16.

As mentioned earlier Appendix D is the minimum scope and detail for the inspection. Part 43.11 is the content, form, and disposition of the records for the inspection. Part 43.15 are some added rules for inspection to ensure all aspects of Airworthiness are met, a checklist is used, and certain engine checks are performed post inspection. Part 43.16 addresses Airworthiness Limitations (AL) which are maintenance items the FAA has approved that carry the same weight as an Airworthiness Directives. AL can be found in chapter 4 of the maintenance manual and in the Instructions for Continued Airworthiness for an installed STC.

There are several other parts in 43 that regulate Maintenance, Preventive Maintenance, and Alterations. Those don’t apply (yet) because we’re only dealing with the requirements of the annual inspection. Key word being Inspection, not maintenance. Maintenance is what you may or may not decide to do after the inspection is completed, but that should be a separate event.

Mechanics/Inspectors often mush together the inspection and the repair of the found discrepancies into one job. They are two independent events governed by different regulations. Trying to make it all happen at the same time is a matter of convenience and habit for the inspector/mechanic/shop.

Without detailed or written guidance from the aircraft’s maintenance manager (that’s you), most inspectors will choose the airframe manufacturer’s annual inspection checklist. These are found in chapter 5 of the Cirrus Aircraft Maintenance Manual and include a long list of things that Cirrus would like to have inspected. Inspectors are comfortable with this list as it is presumed to cover all the bases and is very defined. Using a custom annual checklist may put an inspector outside their comfort zone. They may also feel that just using the very basic Appendix D to be insufficient for today’s high performance complex aircraft.

In the two components of airworthiness, conformity and safety, conformity is easy to define and quantify. Determining if a particular finding is safe is a much more subjective determination and is where discord may creep into the conversation.

Inspectors often have different views of the purpose for the annual inspection than you or the FAA may have. They may feel that the plane should be returned to some better version of its current self. They also may attempt to impose their personal ideas about the urgency of manufacturer “mandatory” service bulletins or time between overhaul for various components.

I’ve found that very few mechanics/shops will suggest that manufacturers’ service bulletins or TBOs are mandatory just to get more work. For the most part, they truly believe these are mandatory if that’s the label used by the manufacturer. For many, the deeper the inspection, the better.

The Owner (You)

Your purpose for the annual inspection is, at a minimum, the same as the FAA plus whatever extra items you want inspected. If the plane is nearing the end of warranty, you may want lots of extra items checked to be sure you get the most from the warranty experience. You may have researched and discovered that a certain service bulletin or other special inspection is worth looking into. Those decisions are yours to make.

As a matter of fact, according to Part 43.15(c)(2), you may create your own annual inspection checklist and provide it to your inspector. It would be a surprise to most any inspector for an owner to show up with a custom-made annual inspection checklist, but it’s legit. One would want to have a conversation about this with the inspector in advance of the inspection start date.

Hopefully, the annual finds safety items before they become a problem without being excessively invasive. Unfortunately, the annual can be more invasive than it should be, and inspectors often have an inflated view of their role in the process. It is the aircraft owner’s job to manage the process while still allowing the inspector to perform their duties within the scope of the regulations.

If you want your aircraft to remain like new forever, let the inspector know so every possible discrepancy or chipped paint is found and documented. If you want just the most basic inspection that follows the regulations (conforms and is safe), then that is your choice. Everything in between is possible if you have done your homework into what you feel is important.

There is no FAA requirement to comply with the Cirrus MM 5 annual inspection checklist or manufacturer’s SB or TBO. The exception to the SB is when an AD refers to using a specific portion of a SB for compliance. That does not mean you should summarily discount a manufacturer’s recommendations. What an owner should do is investigate these manufacturers’ recommendations and see if they seem appropriate for your aircraft. The recommended 500-hour magneto inspection is a perfect example of a manufacturer recommendation that everyone should follow. Cirrus recommends removing the left aileron to inspect for looseness of the roll trim mechanism, which is a very good idea even though it isn’t an FAA requirement, nor is it included in Appendix D.

During your education on aircraft ownership, you may learn of other items not mentioned by the FAA or the manufacturer that should be added to your personal annual checklist. Borescoping the inside of the engine to document condition for future comparison isn’t on any checklist, but you really want to do that. There’s no requirement to download the engine data for review, but it’s a very important tool for determining engine health, and you really want to do that too.

The FAA makes their expectations clear by way of written regulations. The hired inspector will have their own personal expectations that you will have to navigate. It’s important to know where the FAA requirements end, and the personal agenda of the inspector begins so you know how best to imprint the event with your desire and expectations. It’s your responsibility to maintain an airworthy airplane, which means you must be informed to know what is best to do and what might be best not to do.

©  Paul New 2024