According to Travel and Leisure, there has never been a crash due to a phone not being in airplane mode. It's more of a courtesy to make sure that there isn't distracting interference. Even though the plane won't crash, it's important to switch your phone to airplane mode.

If you don’t put your phone on airplane mode in 2026, the most likely result is extreme battery drain and potential expensive roaming charges, rather than a plane crash. When a phone is not in airplane mode at high altitudes, it loses contact with ground towers and begins "revving its engine" to find a signal, transmitting at maximum power which drains the battery in a matter of hours. From a safety perspective, while modern aircraft are heavily shielded against electromagnetic interference, active mobile signals can still cause "audible interference"—a buzzing or clicking sound—in the pilots' headsets. This is particularly distracting during critical phases like takeoff and landing when clear communication with Air Traffic Control is vital. In 2026, with the rollout of 5G near airports, some airlines are even more cautious about potential interference with sensitive radio altimeters. While your phone won't cause the plane to fall out of the sky, it is considered a significant breach of etiquette and a minor safety risk that can lead to warnings or fines from the flight crew.