Hawaiian Airlines flight 35 was headed from Phoenix to Honolulu on Dec. 18 when, about 40 minutes away from the destination, the captain saw a cloud shoot up vertically, like a smoke plume in front of the plane, according to the NTSB report.
The cloud “shot up” toward the aircraft in a matter of seconds, the report indicated, leaving no time to deviate. The captain then called the lead flight attendant to notify her of possible turbulence, but within seconds, the plane experienced turbulence strong enough to the point that some passengers said they were floating off their seats.
Video from inside the aircraft also shows damage to the plane.
“This was really a hard piece of turbulence to anticipate because there was nothing showing on the radar and at these altitudes, there’s very little moisture,” said Peter Forman, an aviation expert and retired commercial pilot. “So if you’re going to pick something up on radar, it’s the stuff way below you.”
The National Weather Services said these types of weather events are rare and they can happen in the blink of an eye.
The report said the NWS did issue a warning for thunderstorms in the area, but there were no pilot reports of severe turbulence along the route before the incident.
“Some of these updrafts or upward motions can be 40 mph or more, so nothing can be there and then in a matter of minutes you can have a well-developed cloud in front of you,” said Derek Wroe, a National Weather Service meteorologist.
Six passengers were seriously injured and 19 sustained minor injuries, the NTSB said. The aircraft experienced minor damage.