What is AOG in Aviation? (Aircraft On Ground)

In the world of aviation, time is of the essence. Every minute a plane is grounded has a significant impact on both the airline and its passengers. This is where the term “Aircraft on Ground” (AOG) comes into play. AOG refers to the status of an aircraft that is unable to fly due to a technical issue or lack of spare parts. In such cases, the aircraft is temporarily out of service, causing delays and disruptions to flight schedules.

For airlines, dealing with AOG situations efficiently is crucial to minimize the negative impact on their operations. Airlines strive to keep their fleet in the air, ensuring that all planes are in optimal condition and ready to take off as scheduled. However, unforeseen issues can arise, bringing an aircraft to a standstill on the ground.

What Causes an Aircraft to be AOG?

There are various factors that can contribute to an aircraft being labeled as AOG. These include:

  • Mechanical Issues: Faulty components, system malfunctions, or structural problems can render an aircraft unfit for flight. These technical issues must be addressed promptly to get the aircraft back in service.
  • Lack of Spare Parts: Sometimes, a necessary replacement part may not be immediately available. It could be due to logistical challenges, such as the part being located at a different maintenance facility or on backorder. This delay in acquiring the required spare parts can prolong the AOG status of an aircraft.
  • Maintenance Checks: Scheduled maintenance checks are essential for the safety and airworthiness of an aircraft. However, these checks can sometimes uncover unexpected issues that require further attention and repair. If the maintenance requires more time than initially planned, the aircraft may be grounded until all necessary repairs are completed.
  • Weather Conditions: Extreme weather events, such as hurricanes, heavy snowfall, or thunderstorms, can lead to flight cancellations and AOG situations. Adverse weather conditions can affect the operation of the aircraft or compromise safety, making it necessary to ground the plane until the weather clears.
  • Unforeseen Circumstances: Other unpredictable events, such as bird strikes, foreign object damage, or fuel leaks, can instantly render an aircraft AOG. These incidents require immediate investigation and rectification before the aircraft can resume normal operations.

How Do Airlines Handle AOG Situations?

When an aircraft is declared AOG, airlines initiate a process to resolve the issue as quickly as possible. Time is of the essence, and airlines employ various strategies to minimize the downtime of their grounded aircraft. Here are some key steps taken by airlines to handle AOG situations:

1. Prompt Identification: As soon as a technical issue is detected or reported, the airline’s maintenance personnel must promptly identify the problem. This involves conducting thorough inspections, utilizing diagnostic tools, and consulting manuals and technical resources to diagnose the root cause of the issue.

2. Spare Parts Acquisition: If the AOG is due to a lack of spare parts, the airline’s logistics and procurement team must make every effort to secure the required components as quickly as possible. This may involve coordinating with suppliers, searching for alternative sources, or even arranging expedited shipping to ensure the timely arrival of the parts.

3. Expedited Repairs: Once the issue has been identified and necessary spare parts are available, the airline’s maintenance crew works diligently to rectify the problem. Technicians and engineers prioritize the repairs and carry out the necessary maintenance procedures to bring the aircraft back to airworthy condition.

4. Collaboration with OEMs: Original Equipment Manufacturers (OEMs) play a crucial role in resolving AOG situations. Airlines often collaborate with the manufacturers of their aircraft and components to obtain technical assistance, access specialized knowledge, and expedite the repair process.

5. Crisis Management: AOG situations can disrupt an airline’s operations and cause inconvenience to passengers. Airlines have dedicated teams and protocols in place to manage such crises effectively. These teams coordinate with affected passengers, provide necessary accommodations or rebookings, and keep stakeholders informed about the progress.

Efficient handling of AOG situations requires effective communication, well-established supply chains, and skilled maintenance staff. Airlines strive to minimize the impact of AOG on their operations, customer satisfaction, and revenue.


Aircraft on Ground (AOG) is a term used in aviation to indicate the status of an aircraft that is temporarily unable to fly due to technical issues or lack of spare parts. Airlines face the challenge of minimizing the number of AOG incidents and dealing with them swiftly when they occur. Prompt identification, spare parts acquisition, expedited repairs, collaboration with OEMs, and effective crisis management are key strategies employed by airlines to handle AOG situations efficiently. By addressing these challenges effectively, airlines can minimize disruptions, maintain their flight schedules, and ensure a positive experience for their passengers.

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