What is typically the biggest expense for airlines?

Fuel is typically the biggest expense for airlines due to the high consumption of jet fuel required for flights. Airlines operate large fleets of aircraft that consume significant amounts of fuel over distances traveled, which can lead to fuel costs accounting for a substantial portion of their operating expenses. Fluctuations in fuel prices can dramatically impact an airline’s overall profitability and financial planning.

While employee salaries, aircraft maintenance, and airport fees are also significant costs for airlines, they generally do not match the magnitude of fuel expenses. For example, airline salaries are indeed a major expense, but the cost of fuel tends to surpass labor costs, especially as operational demands increase and fuel prices fluctuate. Additionally, while aircraft maintenance and airport fees are vital parts of an airline's budget, they are usually less variable compared to the volatile fuel prices that directly correlate with market conditions and oil supply. Thus, fuel stands out as the largest expense in the operations of airlines.