'American Airlines Flight Case Study Essay\r'

'Cause(s) of adventure\r\nThe National Transportation Safety notice (NTSB) located that the probable cause of this accident was the asymmetrical booth and the ensuing roll of the aircraft because of the uncommanded retraction of the left flank outboard leading leaping supplys and the loss of st entirely warning and slat disagreement indication systems resulting from bread and butter-induced legal injury leading to the breakup of the offspring 1 locomotive and power power pylon convention at a deprecative point during takeoff. The separation resulted from damage by uncomely caution routines which let to distress of the pylon structure.\r\n morphologic and Mechanical Factors\r\n afterwards a thorough test of the pylon shackle points, fractures and deformations at the separation points in the antecedent bulkhead and thrust link were all feature article of overload. Testimony indicated the forklift was not officeed for a stop consonant of time because it ran ou t of fuel. Post accident forklift tests showed that on a lower floor these conditions leakage would allow a drift spile of 1 inch in 30 minutes. performance of 0.4 inch or less would produce a 7 inch fracture at the lip.\r\nl land up Factors\r\nThe design and interrelationship of the essential systems as they were affect by the structural loss of the pylon contributed to this accident. relief valve control, hydraulic, and electrical systems in the aircraft were all affected by the pylon separation. When the railway locomotive separated from the pylon hydraulic pressure and fluid were lost and not recoverable. The separation also severed the electrical wire bundles deep down the pylon which included the main feeder circuits in the midst of the generator and the No 1 a.c. generator bus. The fledge crew was unable to restore power to the aircraft.\r\nThe failure of locomotiveering to ascertain the damage-inducing potential of a number which deviated from the manufacturerâ₠¬â„¢s recommended procedure was another contributed factor. The procedure in question was the removal of the pylon attaching computer hardware and the positioning of the forklift. As a result, maintenance military force altered the sequence of hardware removal.\r\nInvestigation Board Findings\r\nThe engine and pylon assembly separated each at or immediately after liftoff. The evasion crew was committed to continue the takeoff.\r\nThe aft end of the pylon assembly started to separate in the forward flange of the aircraft bulkhead. The structural separation of the pylon was caused by a over(p) failure of the forward flange of the aft bulkhead after its residual strength had been critically reduced by the fracture and by and by(prenominal) serve life. The length of the overload fracture and fatigue faulting was about 13 inches.\r\nAll electrical power to the number 1 a.c. generator bus and number 1 d.c. bus was lost after the pylon separated. The captains flight director instr ument, stall warning system, and slat disagreement systems were rendered inoperative. Power was never restored.\r\nThe number 1 hydraulic system was lost at pylon separation. Hydraulic lines and follow up cables of the drive actuator for the left wing’s outboard leading edge slat were severed by the separation of the pylon and the left wing’s outboard slats recant during climb out. The retraction of the slats caused an asymmetric stall and subsequent loss of control of the aircraft.\r\nThe pylon was damaged during maintenance performed on March 29 and 30, 1979 at the American Airlines Maintenance Facility in Tulsa, Oklahoma. Engineering effect developed procedures for removing the pylon and engine that deviated from manufacturers procedures, and did so without perform proper tests.\r\nRecommendations\r\nThe NTSB recommended that the Federal air Administration (FAA) core immediately an emergency Airworthiness Directive to inspect all pylon attach points by approved superintendence methods.\r\nIssue an Airworthiness Directive to require and immediate watch of all DC-10 aircraft in which an engine pylon assembly had been removed and reinstalled for damage to the wing-mounted pylon aft bulkhead, including its forward flange and the attaching spar web and fasteners.\r\nIssue a Maintenance Alert Bulletin directing FAA maintenance inspectors to contact their assigned carriers and advise them to immediately go against the practice of lowering and raising the pylon with the engine still attached and adhere to recommended manufacturer procedures.\r\nOutcomes\r\nAfter a series of post accident inspections let out damaged aft bulkheads in the wing to the engine pylons, the Administrator of the FAA issued an Emergency Order of abeyance on June 6, 1979, which suspended the DC-10 series aircraft type certificate until much(prenominal) time as it can be determine that the DC-10 aircraft meets the certification criteria of Part 25 of the FAR and is p ensionable for a Type Certificate.\r\nTwenty days later the FAA issued Special Federal Aviation Regulation 40 which prohibited the operation of any model DC-10 aircraft within the airspace of the United States.\r\nOn July 13, 1979, after a series of formal investigations, the Administrator found that the DC-10 met the requirements for takings of a type certificate. And the Emergency Order of Suspension was terminated.\r\nIn November 1979 the FAA fined American Airlines $500,000 for using faulty maintenance procedures on its DC-10 aircraft by using forklifts to mate the complete engine/pylon assembly with the wing attachment points. Continental Airlines was fined $100,000 on a similar charge.\r\nReferences\r\nAviation Safety Network. Retrieved October 20, 2010, from http://aviation-safety.net/database/record.php?id=19790525-2\r\nNTSB. (1979). Aircraft Accident Report, American Airlines, Inc. Flight 191. Retrieved October 20, 2010, from http://www.airdisaster.com/reports/ntsb/AAR79- 17.pdf\r\n'