Non-pertinent discussions between a PSA Airlines captain and first officer were the root cause behind a runway overrun accident at the Yeager airport in Charleston, West Virginia on 19 January, says the US National Transportation Safety Board (NTSB) in a final report.
None of the 31 passengers or three crewmembers were injured when US Airways Express Flight 2495 exited the runway and came to rest 39m (128ft) into a 139m engineered material arresting system (EMAS) bed at the end of Runway 23 after a high-speed rejected take off (RTO).
The NTSB lists the probable cause as "the flight crewmembers' unprofessional behaviour, including their non-adherence to sterile cockpit procedures by engaging in non-pertinent conversation, which distracted them from their primary flight-related duties and led to their failure to correctly set and verify the flaps".
Rather than reject the takeoff per PSA procedures, the captain, after noting the incorrect flap setting, had attempted to command the flaps to the correct setting as the aircraft accelerated through 120kt (222km/h). Configuration warnings sounded soon after.
The CRJ ultimately reached about 140kt, 13kt above takeoff speed (V1), before the captain initiated the RTO. According to Bombardier calculations, the aircraft would have been stoppable on the 1,920m (6,300ft) runway had the pilots initiated the rejected takeoff at the V1 speed.
The NTSB says the aircraft entered the ESCO-built engineered materials arresting system (EMAS) just past the runway end while travelling at 50kt. The EMAS was installed in 2007 to bring the runway overrun safety area up to US FAA standards. The terrain "drops off sharply about 350ft" past the runway end, the NTSB notes.
"If this incident had occurred before the installation of the EMAS, the airplane most likely would have travelled beyond the length of the original safety area and off the steep slope immediately beyond its end," says the NTSB.