Southwest Airlines Flight 812

Southwest Airlines Flight 812

The Boeing 737–300 involved in the incident, registration N632SW, pictured in 2007.
Incident summary
Date	1 April 2011 (2011-04)
Type	In-flight structural failure leading to rapid decompression
Site	near Yuma, Arizona
Passengers	118
Crew	5
Injuries	2 (minor)
Fatalities	0
Survivors	123 (all)
Aircraft type	Boeing 737-3H4
Operator	Southwest Airlines
Tail number	N632SW
Flight origin	Phoenix Sky Harbor Int'l Airport (KPHX)
Destination	Sacramento Int'l Airport (KSMF)

Southwest Airlines Flight 812 (SWA812, WN812) was a scheduled US passenger aircraft flight between Phoenix, Arizona (PHX) and Sacramento, California (SMF). On April 1, 2011, the Boeing 737–300 operating the route made an emergency landing in Yuma, Arizona after a 6 ft (1.83 m) hole appeared in the top of the airplane's fuselage above the cabin.^[1] A rapid depressurization at 34,400 ft (10,485 m) ensued and the crew performed an emergency descent.^[2][3]

Aircraft

The aircraft involved was Boeing 737-3H4 N632SW, msn 27707.^[4] It was built in 1996 and delivered to Southwest on June 13 of that year.^[5]

Incident

Flight 812 was a domestic scheduled passenger flight from Phoenix, Arizona to Sacramento, California. On April 1, 2011, it was carrying five crew and 118 passengers. At 15:57 local time (22:57 UTC),^[6] while climbing through FL344 to reach FL360,^[7] a loud bang was heard and one of the ceiling tiles dislodged.^[1] A flight attendant received minor injuries. A passenger also received minor injuries, but was treated at the airport along with the flight attendant.^[7][8] Oxygen masks deployed and the pilots performed a rapid descent to 11,000 ft (3,353 m).^[1] An emergency landing was made at the joint Marine Corps Air Station Yuma / Yuma International Airport.^[1] The aircraft landed at 16:23.^[6] A spare aircraft with maintenance technicians, ground crew, and customer service agents was dispatched from Phoenix to take the passengers to Sacramento.^[8] The replacement aircraft was expected to reach Sacramento with a 4-hour delay to the passengers on board Flight 812.^[7]

This was the second structural failure, rapid decompression, and emergency landing for Southwest Airlines in two years. Southwest Airlines Flight 2294, also a 737–300, had a football-sized hole appear in its fuselage on July 13, 2009. That aircraft also made a safe emergency landing.^[9]

Aftermath

Inspection of the aircraft at Yuma revealed a tear in the fuselage, reported as being between 3 feet (0.91 m) wide and 6 feet (1.8 m) long.^[7][10] Southwest grounded 80 of its Boeing 737-300s for inspection following the incident.^[4] The grounded aircraft were those that had not had the skin on their fuselage replaced.^[11] Five aircraft were discovered to have cracks.^[12] The aircraft were to be repaired and returned to service.^[11] As of April 3, Boeing was developing a Service Bulletin for the inspection of similar aircraft.^[13]

On April 5, 2011, the FAA issued an emergency Airworthiness Directive (AD) requiring operators of 737 series 300, 400 and 500 aircraft to increase the frequency of inspections of lap joints on high flight cycle airframes. The AD requires that aircraft with over 30,000 cycles be inspected within 20 days of receipt of the AD, or of reaching 30,000 cycles. For aircraft with over 35,000 cycles, the inspection is required within 5 days. The AD also requires periodic inspections of the same joints at every 500 cycles for aircraft with over 30,000 cycles.^[14] The AD refers to a range of airframes, line numbers 2553–3132 inclusive, totaling 580 aircraft.^[15] Of the total of 580 aircraft, only 175 aircraft currently meet the 30,000 cycle requirement, with 80 of those operating in the US.^[16] The FAA AD is effective to only the portion of those that are registered in the US, since the FAA can only mandate such changes in the US. Countries with reciprocity airworthiness agreements will also follow the AD, but other nations are not required to adhere to the ruling.^[17] As a result of the incident, the FAA investigated Boeing's manufacturing techniques to discover whether or not they had any bearing on the cause of the failure. The incident aircraft was not considered to have a high number of cycles. Boeing co-operated with the FAA in the investigation.^[18]

Air New Zealand inspected all fifteen of their 737-300s and Qantas inspected four of their 21 737-400s.^[19] Several of the thirty-seven 737-400s operated by Malaysia Airlines were also to be inspected.^[20]

Investigation

The Federal Aviation Administration sent an inspector to Yuma. The National Transportation Safety Board opened an investigation into the incident.^[21] A Go Team was sent to Yuma on April 2.^[22] Inspection of the 5 feet (1.5 m) long tear revealed evidence of pre-existing fatigue. The tear was along a lap joint. In March 2010, cracks had been found and repaired in the same place on the accident aircraft.^[11][13]

References

1. ^ ^{a b c d} "Six-foot hole opens in 737 during flight". King5 News. http://www.king5.com/news/Southwest-flight-to-Phoenix-diverted-to-Yuma-119100294.html. Retrieved April 2, 2011. 
2. ^ "'Plane going down. Love you'". MSNBC. http://www.msnbc.msn.com/id/42385570/ns/travel-news/. Retrieved April 2, 2011. 
3. ^ Pew, Glenn (April 2011). "Southwest In-Flight Fuselage Rupture (With Video)". AvWeb. http://www.avweb.com/avwebflash/news/SouthwestAirlines812_InFlightFuselageRupture_204403-1.html. Retrieved April 2, 2011. 
4. ^ ^{a b} Kaminski-Morrow, David. "Southwest grounds 80 737s after jet holed in flight". Flight International. http://www.flightglobal.com/articles/2011/04/02/355079/southwest-grounds-80-737s-after-jet-holed-in-flight.html. Retrieved April 2, 2011. 
5. ^ "N632SW". Airframes. http://www.airframes.org/reg/n632sw. Retrieved April 2, 2011. 
6. ^ ^{a b} "N632SW Accident description". Aviation Safety Network. http://aviation-safety.net/database/record.php?id=20110401-0. Retrieved April 3, 2011. 
7. ^ ^{a b c d} Hradecky, Simon. "Accident: Southwest B733 near Yuma on Apr 1st 2011, hole in fuselage, sudden decompression". Aviation Herald. http://avherald.com/h?article=43a4ac26&opt=1. Retrieved April 2, 2011. 
8. ^ ^{a b} "Southwest Airlines Responds to Loss of Pressurization Event on Flight From Phoenix to Sacramento". Southwest Airlines. http://www.southwest.com/about_swa/press/prindex.html?int=GFOOTER-ABOUT-PRESS. Retrieved April 2, 2011. 
9. ^ Goldsmith, Sam. "Southwest Airlines Flight 2294 lands in West Virginia with football-sized hole in fuselage". New York: NY Daily News. http://articles.nydailynews.com/2009-07-14/news/17929424_1_southwest-jet-emergency-landing-southwest-airlines-flight. Retrieved April 2, 2011. 
10. ^ "Holed Southwest Airlines flight makes emergency landing". BBC News. April 2, 2011. http://www.bbc.co.uk/news/world-us-canada-12945453. Retrieved April 2, 2011. 
11. ^ ^{a b c} Christie, Bob. "NTSB: Cracks found in 3 grounded Southwest planes". Associated Press via KPUA Hawaii. http://hosted.ap.org/dynamic/stories/U/US_SOUTHWEST_FLIGHT_DIVERTED?SITE=KPUA&SECTION=HOME&TEMPLATE=DEFAULT. Retrieved April 4, 2011. 
12. ^ Ranson, Lori (April 7, 2011). "Southwest starts lap joint repairs on five aircraft". Flight International. http://www.flightglobal.com/articles/2011/04/07/355330/southwest-starts-lap-joint-repairs-on-five-aircraft.html. Retrieved April 9, 2011. 
13. ^ ^{a b} "NTSB provides update on investigation of Southwest Flight 812" (Press release). NTSB. April 3, 2011. http://www.ntsb.gov/Pressrel/2011/110403.html. 
14. ^ Maxon, Terry. "FAA issues emergency directive for Boeing 737 inspections". The Dallas Morning News. http://aviationblog.dallasnews.com/archives/2011/04/faa-issues-emergency-directive.html. Retrieved April 5, 2011. 
15. ^ Hradecky, Simon. "FAA Emergency Air Worthiness Directive regarding Boeing 737 skin cracks". Aviation Herald. http://avherald.com/h?article=43a83ca1&opt=1. Retrieved April 6, 2011. 
16. ^ Ostrower, Jon. "Boeing issues service bulletin for premature 737 Classic lap-joint cracking". Flightglobal. http://www.flightglobal.com/articles/2011/04/06/355216/boeing-issues-service-bulletin-for-premature-737-classic-lap-joint.html. Retrieved 7 APril 2011. 
17. ^ "FAA 737 inspection AD covers 175 jets". Leeham News and Comment. http://leehamnews.wordpress.com/2011/04/04/faa-737-inspection-ad-covers-175-jets/. Retrieved April 7, 2011. 
18. ^ Kirby, Mary (April 13, 2011). "MROAM: FAA studying Boeing manufacturing techniques after Southwest 737 rupture". Flight International. http://www.flightglobal.com/articles/2011/04/13/355527/mroam-faa-studying-boeing-manufacturing-techniques-after-southwest-737.html. Retrieved April 14, 2011. 
19. ^ Horton, Will (April 6, 2011). "ANZ and Qantas to inspect 737 Classics for fatigue cracks". Flight International. http://www.flightglobal.com/articles/2011/04/06/355223/anz-and-qantas-to-inspect-737-classics-for-fatigue-cracks.html. Retrieved April 9, 2011. 
20. ^ Yeo, Ghil-Lay (April 8, 2011). "MAS carries out preliminary inspections on 737s". Flight International. http://www.flightglobal.com/articles/2011/04/08/355332/mas-carries-out-preliminary-inspections-on-737s.html. Retrieved April 9, 2011. 
21. ^ "Passengers Of Damaged Southwest Flight Arrive In Sacramento". CBS. April 1, 2011. http://sacramento.cbslocal.com/2011/04/01/flight-southwest-yuma-decompression/. Retrieved April 2, 2011. 
22. ^ "NTSB LAUNCHING TEAM TO INVESTIGATE AIRLINER FUSELAGE RUPTURE". National Transportation Safety Board. http://www.ntsb.gov/Pressrel/2011/110401.html. Retrieved April 2, 2011. 

See also

	Arizona portal
	Aviation portal

• Aloha Airlines Flight 243
• Southwest Airlines Flight 2294

External links

External images
	Photos of the aircraft involved at airliners.net

• "Southwest Airlines Responds to Loss of Pressurization Event on Flight From Phoenix to Sacramento." Southwest Airlines.
• Full list of operators affected by the AD