The Chart That Shows Why Asiana Flight 214 Crash Landed

The cause of the deadly crash landing of Asiana Flight 214 on July 6 may not be clear, but it's easy to see why the plane hit the ground well short of the runway at San Francisco International Airport.

The target speed for the Boeing 777 — the speed at which it should have been flying moments before landing — was 137 knots (158 mph). In a press conference, NTSB Chairman Debbie Hersman said that at the moment of impact, the jet's speed was just 106 knots (122 mph).

"We're not talking about a few knots," she said.

The result of the low speed is that the plane hit the ground before reaching the runway, leaving chunks of debris in the seawall.

Using data from FlightAware.com (and inspired by Flying Professors.net) we created this chart to compare the landing speeds of Asisana Flight 214 on five different days, including the July 6 crash.

It's easy to pick out the failed flight: It's the dark red one, traveling way too slowly at the moment of landing.