Southwest Airlines Flight 812

Flight 812 was a domestic scheduled passenger flight from Phoenix Sky Harbor International Airport, to Sacramento International Airport. On April 1, 2011, it was carrying five crew and 117 passengers. Takeoff and initial climb-out were normal. As the aircraft approached its cruising altitude, at approximately 15:58 local time (22:57 UTC), while climbing through FL344 () to reach FL360 (), a loud bang was heard, recorded as an unidentified noise on the cockpit voice recorder (CVR). According to eyewitnesses, one of the ceiling panels dislodged. The flight attendant had been attempting to make an interphone call to the pilots or a PA announcement to the passengers, instead of immediately donning his oxygen mask as he had been trained. As a result, he lost consciousness, fell, and struck the forward cabin partition, breaking his nose. An off-duty airline employee rushing to assist the flight attendant also lost consciousness, fell, and received a cut to the head. Both regained consciousness as the aircraft descended. == Aircraft ==

The aircraft involved was Boeing 737-3H4 with registration N632SW, manufacturer's serial number 27707, The aircraft fuselage was manufactured at Boeing's facility at Wichita, Kansas, and was shipped in two pieces (forward and aft sections) by rail from Wichita to Boeing's Renton, Washington, facility for final assembly. The Renton facility then joined the forward and aft fuselage sections, completing a drilling and riveting process that had been intentionally left unfinished at the Wichita facility, for ease of production in Renton. The area of fuselage crown skin that would fail in this incident was at the site of the split manufacturing process, where work was partially performed in Wichita and finished in Renton. == Aftermath ==

Inspection of the aircraft at Yuma revealed a section of fuselage skin had fractured and flapped open, causing the rapid decompression. The opening was approximately long and wide. 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. The aircraft were to be repaired and returned to service. The AD refers to a range of airframes, line numbers 2553 – 3132 inclusive, totaling 580 aircraft. Of the total of 580 aircraft, only 175 met the 30,000 cycle requirement at the time of the AD issuance, with 80 of those operating in the United States. The FAA AD is effective to only the portion of those that are registered in the United States, since the FAA can only mandate such changes in the United States. 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 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 inspected all fifteen of their 737-300s and Qantas inspected four of their 21 737-400s. Several of the thirty-seven 737-400s operated by Malaysia Airlines were also to be inspected. Post-incident interviews showed the injured flight attendant had seriously overestimated his time of useful consciousness, and the NTSB renewed its criticism of the FAA's overly-optimistic time of useful consciousness tables and training requirements. == Investigation ==

The Federal Aviation Administration sent an inspector to Yuma. The National Transportation Safety Board opened an investigation into the incident. Inspection of the 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 incident aircraft. The cause was determined to have been a manufacturing error dating from when the aircraft was built. == In popular culture ==

The events of the incident were documented in a series two episode of Aircrash Confidential titled "Maintenance Failure". The event was referenced in a Weekend Update segment of Saturday Night Live in episode 19 of season 36. Kristen Wiig played a flight attendant from the flight named Shelly Elaine. == See also ==