Beware of Bargain-Priced Aircraft Maintenance Services

#FlySafe GA Safety Enhancement Topic

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Cleared for Takeoff

7 min readMay 18, 2023

Inadequate maintenance and inspections are common factors that can cause general aviation accidents. Aircraft owners seeking bargain-priced mechanical services may wind up with an unairworthy aircraft that is returned to service after a cursory and/or improperly performed inspection. Aircraft owners should be wary of such services that are often too good to be true and instead seek qualified aircraft mechanics who emphasize quality and detail during an inspection.

When it comes to aircraft annual inspections, a bargain that’s too good to be true should set off some flags.

Let’s have a look at some of the regulations and what’s required for an aircraft inspection, identify areas where things could be wrong, and review who’s ultimately responsible for the condition of the aircraft.

The $300 Annual

After a Piper Cub accident, inspectors revealed a receipt for a $300 annual inspection among the aircraft’s maintenance records. The annual inspection was $100, labor was $200, and parts, well …, there were no parts. It turns out that this $300 annual might not be the value it initially seems.

For starters, it takes time just to prepare an airplane for inspection. According to 14 CFR part 43 Appendix D, “each person performing an annual or 100-hour inspection shall, before that inspection, remove or open all necessary inspection plates, access doors, fairing, and cowling.” It also states that the mechanic needs to thoroughly clean the aircraft and aircraft engine — not a suggestion.

It’s important to note that a mechanic performing an inspection must have the correct (and properly calibrated) tools, supplies, manuals, and a maintenance facility to perform the job. 14 CFR section 43.13 (b) states that “each person maintaining or altering, or performing preventive maintenance, shall do that work in such a manner and use materials of such a quality that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition (with regard to aerodynamic function, structural strength, resistance to vibration and deterioration, and other qualities affecting airworthiness).

Paragraph (a) states that mechanics “shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices.” The expense of these necessary items and materials, not to mention overhead costs such as electricity, water, rent, insurance, specialized tooling, etc., should be considered in your overall labor costs. In most cases, $300 just wouldn’t cut it.

The Inspection

14 CFR section 43.15 goes over some additional performance rules for inspections, including checklist use. It states that “each person performing an annual or 100-hour inspection shall use a checklist while performing the inspection. The checklist may be of the person’s own design, one provided by the manufacturer of the equipment being inspected, or one obtained from another source. This checklist [at a minimum] must include the scope and detail of the items contained in Appendix D to this part and paragraph (b) of this section [which covers rotorcraft].”

The more complex the aircraft, the more inspection items you’ll need to include on your checklist. Furthermore, Appendix D does not cover modifications, so any supplemental type certificates (STC) and their Instructions for Continued Airworthiness (ICA) must be included in the checklist.

We won’t cover everything in Appendix D here, but a few general items covered during an inspection (where applicable) include:

Fabric and skin — for deterioration, distortion, other evidence of failure, and defective or insecure attachment of fittings.
Systems and components — for improper installation, apparent defects, and unsatisfactory operation.
Seats and safety belts — for poor condition and apparent defects.
Flight and engine controls — for improper installation and improper operation.
Engine section — for visual evidence of excessive oil, fuel, or hydraulic leaks, and sources of such leaks.
Exhaust stacks — for cracks, defects, and improper attachment.
Hydraulic lines — for leakage.
Wheels — for cracks, defects, and condition of bearings.
Propeller assembly — for cracks, nicks, binds, and oil leakage.
Radio and electronic equipment — for improper installation and insecure mounting.

The time and cost of any needed parts or materials is yet another consideration to an aircraft inspection. Beyond the oil and oil filter, there are likely air filters, instrument inlet filters, approved greases and lubricants (e.g., Cessna has a specific grease for the flap actuator on single-engine airframes), cleaning solvents, seals, gaskets, and more.

Inspections are also time to check for Airworthiness Directive (AD) compliance. It’s not uncommon for a maintenance shop to take six hours or more to research the logbooks and verify AD compliance. The owner should receive a compliance sheet showing all AD compliance details and when any recurring ADs must be re-inspected.

Once the inspection is complete, regulations (14 CFR section 43.15 (c) 2, 3) also require mechanics to perform a run-up of the engine(s) to determine satisfactory performance in accordance with the manufacturer’s recommendations.

What Could Possibly Go Wrong?

Quite frankly, a lot could go wrong when an aircraft inspection is rushed or performed improperly. As you can see, there are several items to cover, and a significant amount of time and effort that goes into a proper aircraft inspection.

For example, in the photo below, the throttle control arm disengaged from the serrated half of the throttle shaft when the castellated nut backed off in flight. No cotter pin was installed. Other examples of items that could get overlooked on a rushed inspection might include the primary fuel bowls and screens, air and instrument filters, damage from rodent/bird/insect infestation, an incorrect part, and improperly torqued bolts/hardware.

Another area worth stressing is inspecting the exhaust system for cracks, damage, or corrosion. Unknown or bad repairs can’t be seen unless the system is opened up and inspected like the photo below showing an improper weld. Poor muffler repairs are a great way to introduce carbon monoxide into the cabin.

Who is Responsible?

It is very clear in 14 CFR part 91 (General Operating and Flight Rules) who has the final responsibility of an aircraft’s airworthiness. 14 CFR section 91.403 states that the “owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with 14 CFR part 39.” The owner/operator also must ensure that the mechanic/inspection authority/repair station signs a return to service statement in their logbook records.

It can be a lot for an operator/owner to keep track of, but a quality maintenance facility will help ensure everything is properly accomplished during an inspection. If you’re not sure where to take your aircraft for an inspection, do some research and ask around.

Communication with your maintainers is also crucial before (get quotes and be familiar with any issues), during (what did they find and what options do you have), and after the inspection (what was done and what’s due next).

In summary, don’t skimp on annual inspections. A $300 annual might sound appealing, but it’s hardly a good value when it comes to everything that is required. It’s better to seek reputable maintenance services and pay a fair price. Your life and your family’s lives depend on it!