USAir Flight 405 crashes shortly after takeoff from New York City's LaGuardia Airport, leading to a number of studies into the effect that ice has on aircraft.

USAir Flight 405 was a regularly scheduled domestic passenger flight between LaGuardia Airport in Queens, New York City, New York, and Cleveland, Ohio. On March 22, 1992, a USAir Fokker F28, registration N485US, flying the route, crashed in poor weather in a partially inverted position in Flushing Bay, shortly after liftoff from LaGuardia. The undercarriage lifted off from the runway, but the airplane failed to gain lift, flying only several meters above the ground. The aircraft then veered off the runway and hit several obstructions before coming to rest in Flushing Bay, just beyond the end of the runway. Of the 51 people on board, 27 were killed, including the captain and a member of the cabin crew.

A similar accident had happened three years before, when Air Ontario Flight 1363 crashed shortly after takeoff at Dryden Regional Airport after ice had accumulated on the wings and airframe. Of the 69 passengers and crew, 24 were killed.

The subsequent investigation revealed that due to pilot error, inadequate deicing procedures at LaGuardia, and several lengthy delays, a large amount of ice had accumulated on the wings and airframe. This ice disrupted airflow over the wing, increasing drag and reducing lift, which prevented the jet from lifting off the runway.: 77  The National Transportation Safety Board concluded that the flight crew was unaware of the amount of ice that had built up after the jet was delayed by heavy ground traffic taxiing to the runway. The report also listed the fact that the aircraft had begun its takeoff rotation too early at a lower speed than was standard as a contributing factor to the accident.

Investigators also found that the deicing procedures at LaGuardia were substandard. While the jet encountered a delay up to 35 minutes, they found that the deicing fluid that was being used at the airport, and by the majority of commercial airlines across the United States, was effective for only 15 minutes. The accident led to a number of studies into the effect that ice has on aircraft, and several recommendations into prevention techniques.