What Is Available Seat Kilometres in Airline Economics?
Available Seat Kilometres defined for aviation professionals, with its operational or commercial use, document context and related terminology.
Definition, Documents and Application
Available Seat Kilometres, or ASK, measure airline passenger capacity by multiplying seats offered by the distance flown.
Aviation Glossary
Term: Available Seat Kilometres
Category: Airline Economics & Scheduling
What the Number Can Show
Airlines and investors use ASK to compare capacity growth across routes and fleets more consistently than counting flights or aircraft alone.
How Airlines Use the Metric
Available Seat Kilometres is used to describe capacity, traffic, cost, revenue, schedule performance or asset productivity. It is most useful when the calculation basis is consistent across the periods, airlines or fleets being compared.
Comparison Limits
Airline metrics can be distorted by stage length, fleet mix, geography, accounting treatment, seasonality and business model. A single ratio should therefore be read with the operating context and the underlying numerator and denominator.
Related Aviation Topics
Related ACMI World coverage includes ACMI lease pricing, seasonal ACMI demand, the 2026 capacity environment, aircraft lease rates by model and leading ACMI operators.
Airlines and investors use ASK to compare capacity growth across routes and fleets more consistently than counting flights or aircraft alone.
Available Seat Kilometres FAQ
What does Available Seat Kilometres mean in aviation?
Available Seat Kilometres, or ASK, measure airline passenger capacity by multiplying seats offered by the distance flown.
Why does Available Seat Kilometres matter?
Airlines and investors use ASK to compare capacity growth across routes and fleets more consistently than counting flights or aircraft alone.
Where would an aviation professional encounter Available Seat Kilometres?
It is commonly encountered in airline economics & scheduling documents, procedures, calculations or operating discussions where the underlying technical or commercial issue is relevant.
Can the metric be compared directly between airlines?
Only when the calculation basis and operating context are sufficiently comparable. Stage length, fleet mix, geography and accounting policy can materially change the result.