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

Verified

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:

"Aircraft on Ground" (AOG) signifies an un-flyable aircraft, leading to substantial financial losses for operators due to unexpected mechanical issues.
The author draws a parallel between aircraft being AOG and their personal experience of being "grounded" by a life-threatening bone marrow transplant, highlighting the fragility of both health and machines.
AOG situations can arise suddenly from diverse malfunctions (e.g., a broken flap handle, structural damage) and often necessitate complex solutions, including restricted ferry flights to specialized repair facilities.

See a mistake? Contact us.

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.