by John M. White | | 1 comment
On September 19, 2008 a Learjet 60, N999LJ, crashed on takeoff from the Columbia Metropolitan Airport in South Carolina resulting in the death of the crew and 2 passengers with serious injuries to the other 2 passengers. This unfortunate accident was entirely preventable with the use of just a little common sense, and by the operator of the aircraft being conscientious in the maintenance of the airplane. As with most airplane accidents, this one started before the crew ever entered the aircraft. The caption for the NTSB report on this accident reads "POOR MAINTENANCE STARTED ACCIDENT CHAIN THAT RESULTED IN HIGH-SPEED RUNWAY EXCURSION THAT KILLED FOUR IN 2008, NTSB DETERMINES." The NTSB determined that the jet crashed because the operator failed to maintain the aircraft's tires properly combined with the Captain's decision to reject the takeoff after flying speed had been attained. The First Officer told the Captain that the takeoff should be continued, which would have been standard operating procedure and in accordance with training in the aircraft. The NTSB investigation revealed that the main gear tires were severely underinflated which compromised the integrity of the tires leading to a failure of all 4 main landing gear tires during the takeoff roll. By the time the first main gear tire failed the aircraft passed the maximum speed at which a takeoff could be safely aborted, but the Captained decided to reject the takeoff and deployed thrust reversers. Unfortunately for the crew the tire failure damaged a critical sensor which returned the thrust reversers to the stowed position and the engines continued to provide forward thrust at takeoff power settings. The Safety Board noted that in 2001 while investigating an uncommanded forward thrust accident the design of the aircraft was modified to protect against this eventuality, no one thought about protection for a rejected takeoff. The Chairman of the NTSB, Deborah A.P. Hersman stated that "This accident chain started with something as basic as inadequate tire inflation and ended in tragedy, this entirely avoidable crash should reinforce to everyone in the aviation community that there are no small maintenance items because every time a plane takes off, lives are on the line.” This accident once again demonstrates that, as with almost all aircraft accidents, it was caused by a chain of events. The underinflated tires due to poor maintenance, the Captains decision to abort the takeoff and an inadequate preflight all contributed to this avoidable accident. It reminds us that we can never be too careful, never take anything for granted, and rely upon our training when an emergency arises. Until next time keep your wings straight and level Hersch! JetAviator7 In flying I have learned that carelessness and overconfidence are usually far more dangerous than deliberately accepted risks. — Wilbur Wright in a letter to his father, September 1900.