With no reported fatal accidents involving large commercial jets in scheduled service, 2023 has been widely hailed as one of the safest years in the history of aviation. And the air transport system is safe.

But the aviation system and its safety margins are showing signs of stress. In the United States, there were nearly two dozen serious runway incursions in 2023, up from 16 the previous year. Thankfully, none of those events ended in a fatal accident.

However, tragedy did strike last week when a Japan Airlines Airbus A350 collided with a much smaller Japan coast guard aircraft on a runway at Tokyo’s Haneda Airport. All 379 passengers and crew on the airliner escaped due largely to the professionalism and training of the crew, but five of the six people on board the coast guard aircraft were killed.

Just a few days later, an Alaska Airlines Boeing 737 Max 9 made an emergency landing in Portland, Oregon, after a door plug blew out of the fuselage shortly after takeoff, causing rapid depressurization of the passenger cabin. No serious injuries were reported.