Since the government began collecting flight delay data in 2003, the Federal Aviation Administration’s air-traffic system has generally been the most significant cause of delays in the U.S. That has recently changed as airline miscues have found their way into first place.
Airline miscues include issues like computer glitches, mechanical breakdowns, crew shortages and tardiness, baggage loading, maintenance, and other problems that the airline is responsible for. Bloomberg reports that the airlines themselves have been responsible for hundreds of thousands of passengers experiencing flight delays or cancellations this summer alone.
Computer glitches have been a particularly difficult problem this season. Delta Airlines and Southwest Airlines have both run into computer problems in the past couple of months, each being forced to cancel upwards of 2,000 flights each.
In 2015, airline errors caused 323,454 flight delays, as compared to 6,770 that the FAA was responsible for, which is the widest that the margin has ever been.
Sharon Pinkerton, vice president for legislative and regulatory policy at trade group Airlines for America, says that though airline miscues cause more flight delays than the FAA air-traffic system, that’s because the airlines have helped that system reach an on-time rate of around 80% by working with the FAA and cutting the number of flights to reduce congestion.