Besides fuel prices and pilot problems, the #1 thing keeping aircraft operators up at night is the dreaded AOG. The very thought of an airplane stranded at some distant and unequipped airport is enough to turn even the most hardened veterans into insomniacs, biting their nails in a cold sweat as thousands in lost revenue and costs ratchet up faster than the US National Debt. The potential ripple effect, particularly when that aircraft is eating away at thin margins, is why a thorough AOG and reliable MRO (maintenance, repair and overhaul) strategy is so important.
An AOG has the uncanny ability to especially happen at the worst times. When it does, every minute that aircraft sits on the ground is critical. Although each situation has its own unique set of challenges, a lot of downtime can be avoided with prompt part sourcing and quick shipping on the ground and in the air.
AOG incidents typically follow a general pattern:
1. The airplane becomes disabled.
2. An airline or operator desperately and frantically calls its OEM and MRO for support.
3. An AOG team of quality inspectors, engineers, planners, and operations managers gets dispatched to assess the aircraft's condition.
4. A quality assessment is written up that details the problem that occurred and what parts are needed to rectify the condition.
5. The operator agrees to the scope of work and signs a contract to begin repairs.
6. Parts are ordered and additional personnel, tools, and equipment are rush delivered to the airframe site.
7. Repairs begin, and upon completion are signed off by a quality manager, assuring the aircraft is airworthy and ready for service once again.
8. Ideally, the aircraft can then be repositioned and returned to operation or if necessary, flown elsewhere to finish usually more complex repairs not possible at its AOG airport.
Of course, planning for every single AOG contingency is difficult and not cost-effective in terms of personnel and parts. The range of possible scenarios can range from a simple avionics or equipment failure to an aircraft experiencing a runway incursion, requiring major structural repairs. However, the cost of not developing a strategy before disaster strikes involves severe consequences to service schedules, revenue and passenger satisfaction. Here are three major AOG variables to consider.
The three variables include:
When you have all the information required to perform an accurate analysis, you can begin looking at aircraft material readiness. Identifying critical parts and developing a recommended spare parts list is important for older aircraft that may have limited availability of parts. Generally, big OEMs like Boeing and Embraer outline part information on their planes, but complete MRO support can also be provided, from ordering to repair service so fleet owners can better predict future expenses. Parts can be separated into categories such as no-go, go-if, and go items, need accompanying important details like average interval between unscheduled removal, quantity per aircraft, processing time for ordering, and average time for shop processing. By planning properly, you'll arrive at a comfortable spare float quantity necessary to guarantee each aircraft can be operated without excess and costly inventory.
The best AOG, of course, is the one you never have. But can AOGs ever truly be avoided? Not likely, but they can be minimized. As a critical focus area, aviation fleet management requires detailed planning, preparation, and data to mitigate the impact of an AOG situation.
Many airlines and operators use these following strategies to eliminate or reduce the impact of an AOG:
Preselected Parts - Inventory can be obtained to anticipate AOG-related issues by examining aircraft usage data and identifying problematic parts through a trusted MRO partner. However, availability of parts is only one task in the AOG process. To expedite deliveries, an MRO must be able to provide and contract for reliable, flexible and fast shipping services, generate proper paperwork, and if applicable, understand local import/export regulations. Unexpected customs mishaps have thwarted many carefully crafted AOG logistics plans, causing delays ranging from a few hours to a few weeks. That's never a situation in which you'd want to find yourself, so plan accordingly.
Flyaway kits - Some airlines, for example, arrange a flyaway kit with important items that have a track record of failure. These kits could either be owned by the operator or procured by an aviation services company. Since they would already be in place, immediately availability during groundings would offer substantial downtime mitigation.
Strategic Partnerships - Often, another operator that flies and maintains a similar fleet at a common destination airport can be a valuable strategic partner. A win-win partnership can work wonders.
Cannibalization – In some cases, your best option could be removing a part from an aircraft that has been grounded for maintenance. With quick air/ground shipping, this allows the AOG aircraft to return to service faster rather than waiting for that part to travel through the entire sourcing process. Just don't forget to replace those parts!
While a solid AOG strategy is essential for any successful return to revenue service, having the right MRO and expedited shipping relationship to support that strategy is just as critical. At Tailwind, we're happy to help with your AOG situation and have saved operators many thousands of dollars with quick delivery of their AOG parts, from props to avionics and even larger items like entire wing sections.