Not surprisingly, airplanes appreciate better than most cars. You will rarely find a car on the road from the 1960s or before. If you do, it is usually at or on its way to a car show. Car designs change so drastically from decade to decade that it is easy to place a car’s year by its shape, color, and even taillights.

Airplanes, however, continue to fly many decades and hours after leaving the assembly line. People unfamiliar with aviation are surprised how old some of these aircraft are and how they are still airworthy. Two planes sitting side by side on the ramp may look alike, but one might be a 2010 model, and the other manufactured in 1983.

Aircraft longevity can be attributed to the maintenance and the upkeep that Airframe and Powerplant (A&P) mechanics put into these aircraft. Aircraft owners are legally obligated to ensure their aircraft are properly inspected to maintain the plane’s airworthiness. We are going to look at what it takes to complete the 100-hour and annual inspections.

Terminology

The term 100-hour Inspection is a little misleading. When I tell my friends that I did a 100-hour inspection last week, most of them look at me with wide eyes and ask, “The inspection took 100 hours to do?” This is not true.

The 100-hour inspection refers to how often the inspection occurs, in this case, every 100 hours of flight time. The Federal Aviation Regulations/Aeronautical Information Manual (FAR/AIM) requires flight schools to have a 100-hour inspection performed on all training aircraft. FAR §91.409 states:

No person may operate an aircraft carrying any person (other than a crewmember) for hire, and no person may give flight instruction for hire in an aircraft which that person provides, unless within the preceding 100 hours of time in service the aircraft has received an annual or 100-hour inspection and been approved for return to service.

That means that every 100 hours, the airplane needs to have certain things inspected and serviced in order for it to continue to have flight training performed in it.

The annual inspection is not much different than a 100-hour inspection. The only differences between them are when the inspection is accomplished (every 100 hours versus once a year) and who can perform the inspection. An A&P can do 100-hour inspections, but only an A&P with an Inspection Authorization (IA) can do the annual. All flight school aircraft require both a 100-hour inspection and an annual inspection. Aircraft not used for flight training only require an annual inspection, like your car.

Inspection

A normal 100-hour or annual inspection starts with an aircraft run-up. The mechanic will start the engine and taxi the plane a short distance. During this run-up and taxi, the mechanic is looking for any performance issues with the aircraft. They will check for smoothness of the flight controls and flight surfaces while extending and retracting the flaps and checking the rudder pedals and brakes. The mechanic runs the engine to pre-takeoff settings and performs a magneto check. Finally, the mechanic ensures all required lights are operating. The mechanic notes anything suspicious on a discrepancy sheet.

With the engine warm and the performance checked, the mechanic removes the necessary cowlings and panels, including the nose cowlings, wheel skirts (if installed), and inspection panels under the wings, tail, and fuselage. The mechanic removes these items so they can inspect as much of the plane as possible.

Both the 100-hour inspection and the annual inspection have two parts: the inspection and service items. The inspection is performed first so that if any issue is found that could require it to remain in inspection longer, the mechanic has time to order parts or make repairs.

An IA examines many areas during the inspection, and most inspectors find their own routine to ensure they inspect everything. As the Inspector here at Elon Aviation, I like to break the plane up into different areas during an inspection, such as the engine, right wing, left wing, bottom fuselage, top fuselage, right horizontal stabilator, left horizontal stabilator, rudder, and interior. The list is long, but it keeps me focused because I can work my way from nose to the tail and see everything.

I inspect every bolt, screw, rivet, and connection for wear, cracks, and fatigue from vibration or stress, as well as check every wire, hose, and line that goes through the firewall or runs throughout the engine. The job can be tedious but identifying something that needs repair or replacement and help keep the plane flying safely is rewarding. I treat every inspection as if I am the next pilot to fly the aircraft. The detailed care inspectors take in looking everything over helps keep everyone safe on the ground and in the air.

You might not think an inspector looks inside the airplane’s wing, but we do. Under most aircraft wings are access panels or inspection panels that allow inspectors to view inside a wing with either a mirror or a borescope. You would be surprised at the amount of dirt and particulars that accumulate inside an aircraft wing, even with all the panels closed. When the panels are removed, it allows access to inspect the control cables for fraying or wear.

The inspection process is extensive, but it is not the only part of a 100-hour or annual inspection. Next week, we will look at what entails the second part of an inspection, the service items.

You could say Joseph Cala was born to be in aviation. According to his mother, Joseph's first word spoken was "airplane." During his childhood, he and his parents frequented the local airport to watch planes take off and land. But it was his experience flying a plane at aviation camp when Joseph was 14 that sealed his fate: He would pursue an aviation career. Learn more about Joseph and the rest of the Elon Aviation staff at www.elonaviation.com.