By Jeff Marcus, Chief, NTSB Safety Recommendations Division
Fifteen years ago today, on August 27, 2006, Comair flight 5191, a Bombardier CL-600-2B19, lined up on the wrong runway and crashed during takeoff from Blue Grass Airport, Lexington, Kentucky (LEX), killing 49 people, including the captain and flight attendant. The first officer, who was seriously injured, was the only survivor. This investigation led to several improvements that furthered safety for all air travelers.
The flight crew was instructed to take off from runway 22, a 7,000-foot-long air carrier runway. Instead, they lined up the airplane on runway 26, a 3,500-foot-long general aviation runway, and began the takeoff roll without cross-checking and verifying that the airplane was on the correct runway before takeoff.
Because runway 26 was too short for the takeoff, the airplane ran off the end of the runway, became momentarily airborne, and crashed into the airport perimeter fence, trees, and terrain. The airplane was destroyed by impact forces and postcrash fire.
What We Found
The NTSB investigation determined that there were adequate cues on the airport surface and resources were available in the cockpit to allow the flight crew to successfully navigate from the air carrier ramp to the runway 22 threshold. The flight crew believed that they were taking off on runway 22, even though it was dark when flight 5191 tried to take off and runway 26 was unlighted. We determined the crash was due to:
- the flight crewmembers’ failure to use available cues and aids to identify the airplane’s location on the airport surface during taxi, and
- their failure to cross-check and verify that the airplane was on the correct runway before takeoff.
We also found that the flight crew was engaged in nonpertinent conversation during taxi, resulting in a loss of positional awareness, contributing to the accident. This is a violation of the FAA’s sterile cockpit rule, which bans nonpertinent conversation in critical phases of flight. (As awareness of distraction spread to other modes of transportation—and to distraction by other means—the sterile cockpit rule began to be seen as a forerunner of later anti-distraction measures.)
Although, the probable cause pointed to flight crew actions, our recommended changes covered all aspects of the aviation industry. We not only recommended improving flight crew procedures, but also recommended that moving map displays be required in cockpits to improve situational awareness to help prevent similar accidents in the future.
In addition, we saw other aspects of the aviation industry that could be improved to help prevent similar accidents: improving air traffic control practices and procedures.
Also contributing to the crash was the Federal Aviation Administration’s (FAA) failure to require that all runway crossings be authorized only by specific air traffic control clearances. In this case, the air traffic controller on duty, like the pilots, had the ability to head off the accident, if he was alert and aware of the flight’s surface movements.
But the tower controller who could see the airplane on the airport surface did not detect the flight crew’s lining up to take off on the wrong runway. Instead of monitoring the airplane’s departure, he was not looking inside the control tower while he performed a lower-priority administrative task that could have waited until after transferring responsibility for the airplane.
The controller’s duty times, and sleep patterns indicated that he was most likely experiencing fatigue at the time of the accident. However, his routine practices did not consistently include the monitoring of takeoff. What’s more, the FAA’s policies and procedures at the time were not optimized to prioritize controller monitoring of aircraft surface operations over administrative tasks.
Followers of aviation safety know that the loss of Comair flight 5191 was an accident that brought a focus on preventing fatigue in air traffic controllers. The NTSB recommended, and the FAA implemented, numerous measures improving air traffic control practices and procedures. These included fatigue management programs, training, and, together with the National Air Traffic Controllers Association, working to improve scheduling practices.
Many other recommendations which came out of the tragedy were implemented, advancing crew resource management and airport surface painting and markings, and prohibiting the issuance of a takeoff clearance during an airplane’s taxi to its departure runway until after the airplane has crossed all intersecting runways.
Because the NTSB’s mission is to improve safety, not to punish, finding a human error was by no means the end of the investigation. Instead, the actions of the flight crew were only the beginning. What conditions led to the human error? Was there anything that could have been done to capture the error? Were there other errors in other parts of the transportation system that allowed the crash to transpire? What could prevent the next crash?
The result is that revisions have been made to ensure that the same set of circumstances at play in LEX during the early morning of August 27, 2006, will not lead to another fatal accident.