AOG Cost Calculator: What an Aircraft on Ground Really Costs
When an aircraft is on the ground waiting for a part, the clock costs money every hour. This calculator totals the daily cost of an aircraft on ground and compares an expedited AOG purchase with a standard order, so the decision does not rest on gut feeling.
Your numbers
Revenue lost minus costs you avoid when the aircraft does not fly.
Enter zero if no substitute is used.
Rebooking, hotels and statutory compensation, where applicable.
Include AOG premium, hand-carry courier and customs.
Your results
A decision aid. Contribution loss depends on your schedule, spare aircraft and contracts, and statutory compensation depends on jurisdiction. Enter your own figures and confirm them with finance.
Total cost vs standard lead time
Sweeps Standard order lead time from 0 to 30, holding your other inputs fixed.
Want AOG events costed from your own data?
We can outline a read-only report that ties AOG purchases, delays and invoices together in your ERP.
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How to use the calculator
Start with the cost of one day on the ground: lost contribution, the cost of a substitute aircraft or wet lease, passenger care, idle crew and station cost, and parking or standby labor. Then enter the standard lead time and price, and the AOG delivery time and price including fees and courier. The result shows the total cost of each option, and the break-even number of days saved. The chart shows how the answer changes as the standard lead time grows. When a part is available from the shelf in a day, the answer is obvious. The calculator earns its place when the choice is closer.
The method
Total cost of an option is the part price plus the days on ground multiplied by the daily ground cost. The saving from expediting is the standard total minus the AOG total. The break-even is the AOG premium divided by the daily cost: if the expedite saves more days than that, the premium pays off. Use contribution rather than revenue when you can, because revenue overstates the loss when costs such as fuel and landing fees are avoided. Add statutory compensation only for the share of flights that qualify.
- Day cost = contribution + substitute + passengers + crew + standby
- Option cost = part price + days on ground x day cost
- Break-even days = (AOG price - standard price) / day cost
Reading the result
A negative saving means the standard order is cheaper in total, which happens with a low daily cost, a short standard lead time or a very high AOG premium. A positive saving means expediting pays for itself. Be careful with edge cases: if you can cannibalize a part from another aircraft you keep the daily cost down, but you create a second AOG later, so cost the cannibalization labor and risk. Also check whether a lease or pool exchange is quicker than a purchase before paying a premium.
Common mistakes
The most common error is leaving the daily cost out and comparing only part prices, which almost always favours the cheaper, slower option. The second is counting full revenue as loss when a spare aircraft covers the flights. The third is forgetting that AOG fees often include courier, customs and handling that appear on separate invoices. Finally, teams often fail to record the actual cost after the event. Doing so improves your model and supports the case for a stocked spare or pool agreement next time.
Frequently Asked Questions
What does AOG mean?
AOG stands for aircraft on ground. It describes an aircraft that cannot fly because it needs a part or repair, and it is the highest priority category for parts requests. Many suppliers have a dedicated AOG desk that works around the clock.
Should I use revenue or contribution?
Contribution is better. It is the revenue you lose minus the costs you avoid by not flying, such as fuel, landing and navigation charges. Using revenue overstates the loss. If your finance team has a standard figure for contribution per aircraft day, use that.
Is passenger compensation always a cost?
Not always. It depends on the jurisdiction, the reason for the delay and the route. Some regimes require compensation for certain delays and cancellations, and others do not. Enter an average based on your own history and the share of flights that qualify.
When is a pool exchange better than an AOG purchase?
When a pool or lease exchange can deliver a serviceable unit in about the same time for a lower fee, and your returned unit is repairable. Exchange needs a core to send back, so check core charges and condition rules before you commit.
If your AOG events are tracked across email, spreadsheets and the ERP, we can build a single view of AOG cost per event from your own data. Netray works on-prem with SAP, Infor, Oracle and Dynamics.
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