AOG (Aircraft on Ground)
What does AOG mean in aviation?
AOG (Aircraft on Ground) is a critical term in aviation maintenance used when an aircraft is grounded due to a technical malfunction or missing part, making it unfit to fly. This status requires immediate attention to restore airworthiness and return the aircraft to service as quickly as possible.
An AOG situation can trigger a cascade of operational consequences, from flight delays to revenue losses, making it one of the most urgent classifications in the MRO (Maintenance, Repair, and Overhaul) environment.
Also known as:
Aircraft-On-Ground status
Grounded aircraft event
AOG condition
Why is AOG important in the aviation aftermarket?
AOG is not just a maintenance term — it's a business-critical event. Every grounded aircraft represents a loss of productivity, increased costs, and reputational risk.
In the aviation aftermarket, AOG scenarios demand immediate and coordinated action from suppliers, MRO providers, and logistics partners. Airlines depend on their ability to quickly source certified spare parts, dispatch qualified technicians, and ensure regulatory compliance — often under extreme time pressure.
By focusing on minimizing AOG duration, operators can protect their bottom line, reduce schedule disruption, and maintain high safety standards. For suppliers and aftermarket service providers, being AOG-responsive is a key differentiator and a sign of operational excellence.
What causes an AOG event?
An AOG event can be triggered by a wide range of technical or operational issues that render an aircraft unairworthy. Common causes include:
Unexpected mechanical failure (e.g. engine, hydraulics, avionics)
Expired or missing life-limited parts (LLPs)
Faulty sensors or warning indicators
Damage from bird strikes, lightning, or ground incidents
Delays in part delivery or incorrect inventory provisioning
Preventive maintenance reduces the frequency of AOG events, but even the best-managed fleets are not immune to them. That’s why having robust AOG procedures in place is essential for all operators.
How is AOG handled in real-world MRO operations?
When an AOG event occurs, it triggers an emergency response involving coordination across multiple departments — typically maintenance teams, supply chain management, logistics providers, and quality assurance.
A standard AOG resolution process often includes the following steps:
Diagnosis and reporting: The issue is identified and classified as AOG, with documentation initiated immediately.
Part identification and sourcing: The required component is identified, and inventory checks are conducted across internal stock and external suppliers.
Expedited logistics: If the part is not available on-site, it is shipped via express logistics — often using air freight — to reach the grounded aircraft as fast as
possible.Technical dispatch: Certified maintenance personnel are either on-site or deployed to carry out the repair or replacement.
Installation and compliance checks: The part is installed, tested, and verified to meet regulatory and operational requirements before the aircraft is released back into
service.
In some cases, MRO organizations or airlines maintain dedicated AOG desks that operate 24/7 to streamline this entire process. The effectiveness of the AOG response can mean the
difference between a short delay and a full-day cancellation with significant knock-on effects.
How can airlines resolve AOG situations quickly?
The fastest path to resolving AOG events is having the right infrastructure in place before an aircraft is grounded. That means:
Partnering with global suppliers offering 24/7 AOG services
Having access to strategically located inventory hubs
Establishing dedicated AOG teams and escalation protocols
Ensuring digital tools for part traceability and documentation
Satair provides round-the-clock AOG support through a global logistics network and extensive parts inventory. With on-demand shipping, expert technical support, and decades
of aftermarket experience, we help airlines resolve AOG events — fast.
Best practices for managing AOG in aviation
To reduce both the frequency and impact of AOG incidents, airlines and MRO providers should adopt the following best practices:
Pre-stock critical parts in high-risk or high-traffic regions
Use data analytics to identify failure trends and predict AOG likelihood
Develop clear escalation protocols for AOG events across teams
Maintain strong supplier relationships for 24/7 support
Invest in digital MRO tools to track inventory, shipments, and compliance in real time
Train frontline staff in AOG response and documentation
By embedding AOG readiness into your aftermarket strategy, you turn a reactive crisis into a controlled, strategic response.