Southwest Airlines Flight 812
Encyclopedia
Southwest Airlines
Southwest Airlines
Southwest Airlines Co. is an American low-cost airline based in Dallas, Texas. Southwest is the largest airline in the United States, based upon domestic passengers carried,...

 Flight 812
(SWA812, WN812) was a scheduled US passenger aircraft flight between Phoenix, Arizona
Phoenix, Arizona
Phoenix is the capital, and largest city, of the U.S. state of Arizona, as well as the sixth most populated city in the United States. Phoenix is home to 1,445,632 people according to the official 2010 U.S. Census Bureau data...

 (PHX) and Sacramento, California
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...

 (SMF). On April 1, 2011, the Boeing 737–300
Boeing 737
The Boeing 737 is a short- to medium-range, twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers...

 operating the route made an emergency landing in Yuma, Arizona
Yuma, Arizona
Yuma is a city in and the county seat of Yuma County, Arizona, United States. It is located in the southwestern corner of the state, and the population of the city was 77,515 at the 2000 census, with a 2008 Census Bureau estimated population of 90,041....

 after a 6 ft (1.83 m) hole appeared in the top of the airplane's fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

 above the cabin. A rapid depressurization at 34400 ft (10,485 m) ensued and the crew performed an emergency descent.

Aircraft

The aircraft involved was Boeing 737-3H4 N632SW, msn
Serial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...

 27707. It was built in 1996 and delivered to Southwest on June 13 of that year.

Incident

Flight 812 was a domestic scheduled passenger flight from Phoenix, Arizona
Phoenix Sky Harbor International Airport
Phoenix Sky Harbor International Airport is a joint civil-military public airport located southeast of the central business district of the city of Phoenix, in Maricopa County, Arizona, United States...

 to Sacramento, California
Sacramento International Airport
Sacramento International Airport is a public airport located 10 miles northwest of the central business district of Sacramento, in Sacramento County, California, USA. It is run by Sacramento County...

. On April 1, 2011, it was carrying five crew and 118 passengers. At 15:57 local time
UTC-7
thumb|300px|UTC−07: Blue , Orange , Yellow , Light Blue - Sea areasUTC−07:00 is an identifier for a time offset from UTC of −07....

 (22:57 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...

), while climbing through FL
Flight level
A Flight Level is a standard nominal altitude of an aircraft, in hundreds of feet. This altitude is calculated from the International standard pressure datum of 1013.25 hPa , the average sea-level pressure, and therefore is not necessarily the same as the aircraft's true altitude either...

344 to reach FL360, a loud bang was heard and one of the ceiling tiles dislodged. A flight attendant received minor injuries. A passenger also received minor injuries, but was treated at the airport along with the flight attendant. Oxygen masks deployed and the pilots performed a rapid descent to 11000 ft (3,353 m). An emergency landing was made at the joint Marine Corps Air Station Yuma
Marine Corps Air Station Yuma
Marine Corps Air Station Yuma or MCAS Yuma is a United States Marine Corps air station which is the home to multiple squadrons of AV-8B Harrier IIs of the 3rd Marine Aircraft Wing, Marine Aviation Weapons and Tactics Squadron 1 and Marine Fighter Training Squadron 401 , an air combat adversary...

 / Yuma International Airport
Yuma International Airport
Yuma International Airport , a shared-use airport together with Marine Corps Air Station Yuma, is located three nautical miles south of the central business district of Yuma, a city in Yuma County, Arizona, United States...

. The aircraft landed at 16:23. A spare aircraft with maintenance technicians, ground crew, and customer service agents was dispatched from Phoenix to take the passengers to Sacramento. The replacement aircraft was expected to reach Sacramento with a 4-hour delay to the passengers on board Flight 812.

This was the second structural failure, rapid decompression, and emergency landing for Southwest Airlines in two years. Southwest Airlines Flight 2294
Southwest Airlines Flight 2294
Southwest Airlines Flight 2294 was a scheduled US passenger aircraft flight which made an emergency landing at Yeager Airport in Charleston, West Virginia, on July 13, 2009, after what was described as a "football sized" opening in the airplane's fuselage caused rapid depressurization of the...

, 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.

Aftermath

Inspection of the aircraft at Yuma revealed a tear in the fuselage, reported as being between 3 foot (0.9144 m) wide and 6 feet (1.8 m) long. Southwest grounded 80 of its Boeing 737-300s for inspection following the incident. The grounded aircraft were those that had not had the skin on their fuselage replaced. Five aircraft were discovered to have cracks. The aircraft were to be repaired and returned to service. As of April 3, Boeing was developing a Service Bulletin for the inspection of similar aircraft.

On April 5, 2011, the FAA issued an emergency Airworthiness Directive
Airworthiness Directive
An Airworthiness Directive is a notification to owners and operators of certified aircraft that a known safety deficiency with a particular model of aircraft, engine, avionics or other system exists and must be corrected....

 (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. The AD refers to a range of airframes, line numbers 2553–3132 inclusive, totaling 580 aircraft. Of the total of 580 aircraft, only 175 aircraft currently meet the 30,000 cycle requirement, with 80 of those operating in the US. 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. As a result of the incident, the FAA investigated Boeing's
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

 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.

Air New Zealand
Air New Zealand
Air New Zealand Limited is the national airline and flag carrier of New Zealand. Based in Auckland, New Zealand, the airline operates scheduled passenger flights to 26 domestic destinations and 24 international destinations in 15 countries across Asia, Europe, North America and Oceania, and is...

 inspected all fifteen of their 737-300s and Qantas
Qantas
Qantas Airways Limited is the flag carrier of Australia. The name was originally "QANTAS", an initialism for "Queensland and Northern Territory Aerial Services". Nicknamed "The Flying Kangaroo", the airline is based in Sydney, with its main hub at Sydney Airport...

 inspected four of their 21 737-400s. Several of the thirty-seven 737-400s operated by Malaysia Airlines
Malaysia Airlines
Malaysian Airline System Berhad , DBA Malaysia Airlines , is the government-owned flag carrier of Malaysia. Malaysia Airlines operates flights from its home base, Kuala Lumpur International Airport, and its eastern hub in Kota Kinabalu. It has its headquarters on the grounds of Sultan Abdul Aziz...

 were also to be inspected.

Investigation

The Federal Aviation Administration
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...

 sent an inspector to Yuma. The National Transportation Safety Board
National Transportation Safety Board
The National Transportation Safety Board is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and incidents, certain types of highway crashes, ship and marine...

 opened an investigation into the incident. A Go Team was sent to Yuma on April 2. 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.

See also

  • Aloha Airlines Flight 243
    Aloha Airlines Flight 243
    Aloha Airlines Flight 243 was a scheduled Aloha Airlines flight between Hilo and Honolulu in Hawaii. On April 28, 1988, a Boeing 737-200 serving the flight suffered extensive damage after an explosive decompression in flight, but was able to land safely at Kahului Airport on Maui. The only...

  • Southwest Airlines Flight 2294
    Southwest Airlines Flight 2294
    Southwest Airlines Flight 2294 was a scheduled US passenger aircraft flight which made an emergency landing at Yeager Airport in Charleston, West Virginia, on July 13, 2009, after what was described as a "football sized" opening in the airplane's fuselage caused rapid depressurization of the...


External links

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