AOG: When an Airplane—or We—Can’t Fly

Part 135 flying experience saw a couple of notable aircraft-on-ground situations.

Thursday, October 03, 2024 at 10:41 AM ET

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An AOG situation means the aircraft needs professional service to make it ready to fly. Until then, it’s grounded. [Courtesy: Dick Karl]

Key Takeaways:

AOG (Aircraft on Ground) signifies an un-flyable aircraft, causing substantial financial losses for operators, estimated at $10,000 to $100,000 per hour.
The author draws a parallel between being AOG and his personal experience with a bone marrow transplant, illustrating how unexpected and debilitating events can "ground" both machines and humans.
Through anecdotes like a broken flap handle or ferrying an aircraft with a drilled wing spar, the article emphasizes that complex machines are fragile and unexpected issues can arise anytime, anywhere.

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AOG. Aircraft on ground. This phrase strikes horror in the maintenance department. It means the airplane is not flyable. For an airline or Part 135 operator, AOG means lost revenue. Boeing estimates one hour of AOG costs an airline $10,000 to $20,000 dollars, and in some circumstances, up to $100,000 an hour.

AOG means that even though the operator may have an extensive FAA-approved MEL (minimum equipment list) that allows for flight with certain mechanical discrepancies, it doesn’t apply to this situation. An AOG situation means the aircraft needs professional service to make it ready to fly. Until then, it’s grounded.

Dick Karl

Dick Karl is a cancer surgeon who appreciates the beauty and science involved in both surgery and flying. Dick’s monthly Gear Up celebrates the human side of flying. He writes about his enthusiasm for both the machines and the people who fly and maintain them.