User:Javelin98/sandbox

The incident aircraft had been chartered by Lewis Katz, a millionaire philanthropist and co-owner of The Philadelphia Inquirer and several major sports teams, for a day trip from Atlantic City, New Jersey, to Concord, Massachusetts. In addition to several personal friends, he had also invited Edward G. Rendell, former governor of Pennsylvania, who was unable to accept.

Accident
After concluding his business in Concord, Katz and his party returned to Hanscom Field to depart. The plane prepared to depart at 9:40 PM EDT, lining up on Runway 11 under night visual meteorological conditions. As the plane began its takeoff roll, the pilots realized that they had limited control of the airplane's steering and that the engine throttle levers could not be advanced to full power. The plane passed the maximum speed at which the pilots could have aborted the takeoff, known as V1, but they failed to apply the brakes or reduce the throttles for 10 to 11 seconds after passing that point. The airplane rolled through the paved overrun area and across a grassy area, collided with approach lights and a localizer antenna, passed through the airport’s perimeter fence, and came to a stop in a shallow ravine, where its full load of fuel immediately caught fire. All seven people aboard - two pilots, a flight attendant, and four passengers - were killed, and the airframe was destroyed by the impact and post-crash fire.

Investigation
The National Transportation Safety Board (NTSB) began an investigation immediately, issuing its final report on September 9, 2015. The NTSB found that the flight crew failed to adhere to required pre-flight procedures, something which was found to be a habit for this particular crew. Critically, the pilots failed to conduct a flight control check, which would have revealed that the airplane’s "gust lock" system, which protects the elevator, ailerons, and rudder from wind gusts while the airplane is parked by locking them in place, was still fully engaged and prevented use of those control surfaces. A review of data from the airplane’s quick access recorder revealed that the pilots had neglected to perform complete flight control checks before 98% of their previous 175 takeoffs in the airplane, indicating that this oversight was habitual and not an exceptional event.

The gust lock handle also included an interlock mechanism intended to limit the throttle levers to just enough power for taxiing and idle while engaged. According to Gulfstream, this had been intended to prevent pilots from attempting to take off with the gust lock engaged. However, post-accident testing on other Gulfstream-IV airplanes found that, with the gust lock handle in the ON position, the forward throttle lever movement that could be achieved was 3 to 4 times greater than intended.

The NTSB concluded that the probable cause of the accident was the flight crew’s failure to perform the flight control check before takeoff, which lead to their attempt to take off with the gust lock system engaged, and their delay in aborting the takeoff after they became aware that the controls were locked. Contributing to the accident were the flight crew’s habitual noncompliance with checklists, Gulfstream Aerospace Corporation’s failure to ensure that the G-IV gust lock/throttle lever interlock system would prevent an attempted takeoff with the gust lock engaged, and the Federal Aviation Administration’s failure to detect this defect during the G-IV’s certification.