- Date
- April 1, 2011, 15:57 local (22:57 UTC)
- Place
- Yuma, AZ
- Injuries
- 2 minor, 120 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N632SWBoeing 737
- Defining event
- Enroute-climb to cruise: Aircraft structural failure
- Weather
- Visual (VMC) · Day
- Status
- Completed · report February 26, 2014
- Report
- Approved by Office Director
- NTSB office
- Major Investigations Division
- FAA report
- 20110401007039A
- Case key
- 78737
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
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.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The Safety Board's full report is available at http://www.ntsb.gov/investigations/reports_aviation.html. The Aircraft Accident Brief number is NTSB/AAB-13/02. On April 1, 2011, about 1558 mountain standard time (MST), a Boeing 737-3H4, N632SW, operating as Southwest Airlines flight 812 experienced a rapid decompression while climbing through flight level 340. The flight crew conducted an emergency descent and diverted to Yuma International Airport (NYL), Yuma, Arizona. Of the 5 crewmembers and 117 passengers on board, one crewmember and one nonrevenue off-duty airline employee passenger sustained minor injuries. The airplane sustained substantial damage; postaccident inspection revealed that a section of fuselage skin about 60 inches long by 8 inches wide had fractured and flapped open on the upper left side above the wing. The flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 121 as a regularly scheduled domestic passenger flight from Phoenix Sky Harbor International Airport, Phoenix, Arizona, to Sacramento International Airport, Sacramento, California.
Factual narrative
The Safety Board's full report is available at http://www.ntsb.gov/investigations/reports_aviation.html. The Aircraft Accident Brief number is NTSB/AAB-13/02. On April 1, 2011, about 1558 mountain standard time (MST), a Boeing 737-3H4, N632SW, operating as Southwest Airlines flight 812 experienced a rapid decompression while climbing through flight level 340. The flight crew conducted an emergency descent and diverted to Yuma International Airport (NYL), Yuma, Arizona. Of the 5 crewmembers and 117 passengers on board, one crewmember and one nonrevenue off-duty airline employee passenger sustained minor injuries. The airplane sustained substantial damage; postaccident inspection revealed that a section of fuselage skin about 60 inches long by 8 inches wide had fractured and flapped open on the upper left side above the wing. The flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 121 as a regularly scheduled domestic passenger flight from Phoenix Sky Harbor International Airport, Phoenix, Arizona, to Sacramento International Airport, Sacramento, California.
Aircraft
- Registration
- N632SW
- Reported as
- Boeing 737 (300)
- Category
- Airplane
- Serial number
- 27707
- Engines
- CFM 56, turbo fanCFM 56, turbo fan
- Damage
- Substantial damage
- Flight
- Part 121
- Operator
- Southwest Airlines Co
- Registered owner
- Southwest Airlines Co
- Airworthiness certificate
- Standard, Transport
- Departed
- PHX · Phoenix, AZ
- Destination
- SMF · Sacramento, CA
- Flight plan
- IFR
- Airport
- NYL · Yuma International Airport
Weather
- Conditions
- Visual (VMC) · Day
Docket · 30
The files NTSB released with the investigation on March 7, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 70.3 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.