WASHINGTON - Human error is the probable cause of the Comair crash last August that killed 49 people in Lexington, Ky., the National Transportation Safety Board announced in Washington Thursday.
The pilots of Flight 5191 neglected to notice that they took off from a too-short runway used only by general aviation planes at Lexington's Blue Grass Airport.
The plane's crew, flying together for the first time, did not go through key cross-check procedures to confirm they were on the correct runway. The pilots also violated the "sterile cockpit" rule by engaging in 40 seconds of what the NTSB described as "nonpertinent" conversation one minute after they began taxiing to the runway.
This distraction likely contributed to the pilots' loss of "positional awareness," the NTSB said.
In an eight-hour meeting, the NTSB also cited as a probable cause the Federal Aviation Administration's failure to require that all runway crossings be authorized only by specific air traffic control clearances.
Flight 5191 took off in predawn darkness and was briefly airborne before it clipped some trees, crashed into a farm field 1,800 feet from the end of the runway and burst into flames.
First Officer James Polehinke is the only survivor. He suffered massive injuries as a result of the crash.
The plane's voice recorder shows that Polehinke said it was weird the runway had no lights, but he did not know he was on the wrong one. Polehinke realized his error when the plane was beyond the speed at which it could terminate the takeoff.
"These are good men who were flying this airplane who were attempting to do the right thing, but for whatever reason their heads weren't in the game as they had been in the thousands of hours they had successfully flown up to that moment," said Mark V. Rosenker, NTSB chairman.
Only one air traffic controller was on duty when the accident occurred, which violated the FAA's standard that air and ground responsibilities should be divided between two people. The controller, who had 17 years of experience, cleared the flight for takeoff and turned his back to complete an administrative task.
The controller failed to recognize that Flight 1591 was on the wrong runway, and the NTSB said he might have prevented the crash had he been paying attention.
However, air traffic controllers are not required to monitor aircraft after they have been cleared for takeoff; therefore, he was not used to doing so.
Although the NTSB voted unanimously that the controller was not using his time wisely, the board decided after long deliberation against including his actions as a probable cause.
The NTSB issued a recommendation that air traffic controllers should refrain from all other tasks until they are sure a plane is on the right runway. The board also recommended that takeoff clearance should be prohibited during an airplane's taxi to its departure runway until after the airplane has crossed all intersecting runways.
The Comair crew did not receive two kinds of warnings about a closed runway that required they take an alternate route to the main runway.
The map the pilots had of the airport also contained signage discrepancies that could have led to confusion.
However, the NTSB determined airport signs and cues provided enough guidance for the crew to navigate to the runway. The board did issue a recommendation that airports have better taxiway centerline markings and that runway entrances be clearly marked with holding signs so pilots will know to stop and get clearances.
Other safety recommendations the NTSB issued included requiring all crew members to confirm and cross-check that the airplane is on the right runway before crossing the line for takeoff and installing systems in cockpits to alert pilots if they are on the wrong runway.
Comair President Don Bornhorst said he will work with the FAA to review and adopt the NTSB's safety recommendations.
"In aviation, safety is the expectation of the traveling public, and we continue to work with the aviation community to make safety an absolute given," said Bornhorst, who attended the meeting.
Deborah Hersman, the NTSB board member who was lead investigator, said this was the most searing investigation she has ever had to participate in, both in loss of life and determining a cause.
"It didn't take long for us to realize that, no matter how many people we interviewed, there are no easy explanations for us, no simple solutions," Hershman said. "We couldn't point to one thing and say, ‘Aha, that's the cause of the accident!'"
Some family members of Comair victims attended the meeting. Others watched from hotels in Lexington and Atlanta.
Rep. Ben Chandler, D-Ky., who represents the Lexington area, said he commends the NTSB's investigation.
"As we move forward from the NTSB's investigation, I will continue to press the FAA to promptly implement these recommendations and require mandatory compliance," Chandler said in a statement.
No hearing or regulatory action will ever replace the loss that the victims' friends and families have endured, Rep. Geoff Davis, R-Ky., said in a statement.
"Most importantly, these findings have highlighted that we need to do more to ensure the safety of airline passengers and crews," Davis' statement said. "The FAA must work to address staffing issues and focus on improving our nation's air traffic control system."