Boeing 757-222 N547UA

Summary

On 1 December 2011 at about 21:39 local time, a Boeing 757-222 registered N547UA, operated by United Airlines, was involved in an accident near Modesto, California, United States. 152 people were on board and one was seriously injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

1 December 2011 at 21:39

Classification

Accident

Location

Modesto, California, United States

Coordinates

37.6104, -122.3790

Aircraft

Boeing 757-222

Registration

N547UA

Category

Airplane

Engines

2

Operator

United Airlines

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

Denver → San Francisco

Aircraft damage

Not recorded

Weather

VMC

Light

Day

NTSB number

WPR12LA057

1 person was seriously injured.

The flight's encounter with known severe turbulence associated with mountain wave activity, which resulted in a flight attendant sustaining a broken ankle.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

While en route at flight level (FL) 360, the captain of the commercial air carrier flight requested and was granted a lower altitude (FL 300) to minimize the effect that turbulence was having on the airplane. After the captain received pilot reports indicating that varying degrees of turbulence, mountain wave activity, and low-level windshear existed, he illuminated the seat belt sign and made an announcement for the passengers to be seated. The flight crew then advised the cabin crewmembers of possible turbulence and instructed them to prepare the cabin for landing, stay near their seats, and be seated immediately if turbulence was encountered. About 7 to 10 minutes later, while the airplane was at FL 300, the flight encountered moderate-to-severe turbulence. A flight attendant who was in the lavatory when the turbulence was encountered sustained a broken ankle after being thrown in the air twice.

Quoted verbatim from the NTSB record.