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Last updated: 22 April 2019
Date:Friday 1 April 2011
Type:Silhouette image of generic B733 model; specific model in this crash may look slightly different
Boeing 737-3H4 (WL)
Operator:Southwest Airlines
Registration: N632SW
C/n / msn: 27707/2799
First flight: 1996-06-03 (14 years 10 months)
Engines: 2 CFMI CFM56-3B1
Crew:Fatalities: 0 / Occupants: 5
Passengers:Fatalities: 0 / Occupants: 117
Total:Fatalities: 0 / Occupants: 122
Aircraft damage: Minor
Aircraft fate: Repaired
Location:Yuma International Airport, AZ (YUM) (   United States of America)
Phase: En route (ENR)
Nature:Domestic Scheduled Passenger
Departure airport:Phoenix-Sky Harbor International Airport, AZ (PHX/KPHX), United States of America
Destination airport:Sacramento International Airport, CA (SMF/KSMF), United States of America
Flightnumber: 812
Southwest Airlines Flight 812, from Phoenix-Sky Harbor International Airport, AZ (PHX) to Sacramento International Airport, CA (SMF), diverted to Yuma International Airport, AZ (YUM) after experiencing a rapid depressurization at approximately 34,000 feet.
Upon landing, a 5-foot x 1-foot hole in the crown area was observed on the left side of the airplane, aft of the over-wing exit at the stringer 4L lap joint. Of the 117 passengers and 5 crew members onboard, one flight attendant received a minor injury.
Flightaware data indicate the flight was climbing through about FL344 at 15:57 when the incident happened. It landed at Yuma 16:23.

Probable Cause:

PROBABLE CAUSE: "The National Transportation Safety Board determines that the probable cause of this accident was the improper installation of the fuselage crown skin panel at the S-4L lap joint during the manufacturing process, which resulted in multiple site damage fatigue cracking and eventual failure of the lower skin panel. Contributing to the injuries was flight attendant A's incorrect assessment of his time of useful consciousness, which led to his failure to follow procedures requiring immediate donning of an oxygen mask when cabin pressure is lost."

Accident investigation:
Investigating agency: NTSB
Status: Investigation completed
Duration: 2 years and 11 months
Accident number: DCA11MA039
Download report: Summary report

Forced landing on runway

» Southwest Airlines statement
» Flightaware track
» SKYbrary 

Follow-up / safety actions
On April 2, 2011, Southwest decided to keep a subset (79 aircraft) of its Boeing 737 fleet out of the flying schedule to begin an aggressive inspection effort in cooperation with Boeing engineers.


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This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Phoenix-Sky Harbor International Airport, AZ to Sacramento International Airport, CA as the crow flies is 1033 km (646 miles).

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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