The National Transportation Safety Board (NTSB) on July 26 ruled that the primary cause of the Aug. 27, 2006 early morning fatal crash of Comair Flight 5191, a Bombardier CRJ- 100 regional jet (N431CA), during takeoff from Blue Grass Airport in Lexington, KY, was pilot error.

The Safety Board said the flight deck crew repeatedly missed "abundant cues" that should have alerted them of the fact that they were taking off from the wrong runway. Forty- seven passengers and three crewmembers were on board. Only the first officer survived and is recovering from critical injuries. The captain had passed the controls to the first officer for takeoff.

Additional recommendations to the Federal Aviation Administration were made at the NTSB public accident investigation hearing to guard against future accidents.

After an eleven-month probe, Safety Board investigators determined that the two-man crew failed to conduct a proper pre-flight briefing at the airport under construction. The cockpit voice recorder showed extraneous cockpit conversations in violation of the Federal Aviation Administration’s (FAA) "sterile cockpit" regulation, and failed to react to sure signs that they were taking off from the much shorter general aviation runway versus the air carrier runway.

"It’s very clear to us that the crew made a mistake. Their heads just weren’t in the game here," said NTSB Member Debbie Hersman. Steven Chealander, another Safety Board member and former airline pilot, said "there comes a time for the flight crew to take responsibility. There were cues there. The flight deck crew was not doing their jobs. Human error far outweighs system errors in this case."

Specifically, the NTSB ruled that the probable cause of the Comair regional jet accident was "the flight crew’s 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.

"Contributing to this accident were the flight crew’s non-pertinent conversations during taxi, which resulted in loss positional awareness and the FAA’s failure to require that all runway crossings be authorized only by specific air traffic control clearances," the NTSB determination continued.

"This accident was caused by poor human performance," said NTSB Chairman Mark Rosenker. "Forty-nine lives could have been saved if the flight crew had been concentrating on the important task of operating the airplane in a safe manner."

At about 6:07 a.m., Comair Flight 5191, which was bound for Hartsfield-Jackson Atlanta International Airport, attempted to take off from Blue Grass Airport, but impacted an earthen berm at the end of the runway and crashed on farm land just beyond airport grounds, destroying the turbine-powered regional aircraft. The flight crew had been instructed to take off from Runway 22, an air carrier runway that is 7,003 feet long. Instead, the flight crew lined up the airplane on Runway 26, a 3,501-foot-long unlit general aviation runway, and began the takeoff roll. Runway 26 crosses runway 22 about 700 feet south of the runway 22 threshold.

The Safety Board’s findings were perhaps most notable for the things they concluded weren’t factors in the fatal crash. Board members had considered whether the airport itself and/or the controller on duty in the tower contributed to the crash scenario, but ultimately they pinned most of the blame on the pilots.

Among the non-factors were the flight crew’s lack of a current airport surface map and notices regarding ongoing airport construction to increase the safety areas at each end of Runway 22. NTSB had also considered whether controller fatigue might have contributed to the crash, but in the end the controller on duty was exonerated.

One week before the fatal accident, Taxiway A was closed and barricaded with all lights covered. Taxiway A5 was redesignated Taxiway A. As a result of the construction, said NTSB investigators, there were differences in the airport chart available to the crew and the taxiway signage. However, the investigators said their chart accurately depicted the paved runways on the airport.

The probe also showed that the Comair pilots had not picked up word of the taxiway redesignation, the subject of a local notice to airmen (NOTAM) that is made available to the crew via the Automatic Terminal Information Service (ATIS) and in their flight release paperwork. The Safety Board staff said that even without having seen the local NOTAM, the two pilots should have known better, since construction barricades were visible.

The NTSB investigators noted that although it was the first time that the flight deck crew had flown together, the captain did not conduct a full taxi briefing. They also noted that the crew was stopped at the Runway 26 shortline for nearly one minute "offering ample time to look outside the cockpit to confirm their location."

As Comair Flight 5191 proceeded down the wrong runway, the first officer commented that the runway looked "weird, with no lights." According to the cockpit voice recorder (CVR), the captain replied "yeah." The CVR had also recorded 40 seconds of conversation discussing work schedules, families, a pet and another pilot just prior to their attempted takeoff—-small talk that broke the sterile cockpit rule.

Significant conclusions reached by the Safety Board members included the fact that:

  • Adequate cues existed on the airport surface and available resources were present in the cockpit to allow the flight crew to successfully navigate from the air carrier ramp to the runway 22 threshold.
  • The flight crewmembers’ non-pertinent conversation during the taxi, which was not in compliance with Federal regulations and company policy, likely contributed to their loss of positional awareness.
  • The flight crewmembers failed to recognize that they were initiating a takeoff on the wrong runway because they did not cross-check and confirm the airplane’s position on the runway before takeoff and they were likely influenced by confirmation bias.
  • Even though the flight crewmembers made some errors during their pre-flight activities and the taxi to the runway, there was insufficient evidence to determine whether fatigue affected their performance.
  • The flight crew’s non-compliance with standard operating procedures, including the captain’s abbreviated taxi briefing and both pilots’ non-pertinent conversation, most likely created an atmosphere in the cockpit that enabled the crew’s errors.
  • The controller did not notice that the flight crew had stopped the airplane short of the wrong runway because he did not anticipate any problems with the airplane’s taxi to the correct runway and thus was paying more attention to his radar responsibilities than his tower responsibilities.
  • The controller did not detect the flight crew’s attempt to take off on the wrong runway because, instead of monitoring the airplane’s departure, he performed a lower-priority administrative task that could have waited until he transferred responsibility for the airplane to the next air traffic control facility.
  • The controller was most likely fatigued at the time of the accident, but the extent that fatigue affected his decision not to monitor the airplane’s departure could not be determined in part because his routine practices did not consistently include the monitoring of takeoffs.
  • The FAA’s operational policies and procedures at the time of the accident were deficient because they did not promote optimal controller monitoring of aircraft surface operations.
  • Even though the air traffic manager’s decision to staff midnight shifts at Blue Grass Airport with one controller was contrary to Federal Aviation Administration verbal guidance indicating that two controllers were needed, it cannot be determined if this decision contributed to the circumstances of this accident.
  • Because of the on-going construction project at Bluegrass Airport, the taxiway identifiers represented in the airport chart available to the crew was inaccurate and the information contained in a local NOTAM about the closure of taxiway Alpha was not made available to the crew via ATIS broadcast or in their flight release paperwork.
  • The controller’s failure to ensure that the flight crew was aware of the altered taxiway, a configuration was likely not a factor in the crew’s inability to navigate to the correct runway.
  • Because of the information in the local notice to airmen (NOTAM) about the altered taxiway, a configuration was not needed for the pilots’ way-finding task. The absence of the local NOTAM from the flight release paperwork was not a factor in this accident.

The National Transportation Safety Board determined that "the probable cause of this accident was 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."

After launching the Comair Flight 5191 crash probe, the Safety Board issued two sets of safety recommendations. They urged the FAA to require airlines to establish procedures to make sure their aircraft are aligned for the proper runway and that their pilots are familiar with lighting requirements for night takeoffs. The second set of recommendations dealt with air traffic controller fatigue, vigilance, judgement and safety awareness.

In closing the book on the Comair Flight 5191 accident investigation, the Safety Board made five additional recommendations to the FAA:

  • Require that all 14 Code of Federal Regulations Part 91K, 121, and 135 operators establish procedures requiring all crewmembers on the flight deck to positively confirm and cross check the airplane’s location at the assigned departure runway before crossing the hold short line for takeoff.
  • Require that all Code of Federal Regulations Part 91K, 121, and 135 operators install on their aircraft cockpit moving map displays or an automatic system that alerts pilots when a takeoff is attempted on a taxiway or a runway other than the one intended.
  • Require that all airports certified under 14 Code of Federal Regulations Part 139 implement enhanced taxiway centerline markings and surface painted holding position signs at all runway entrances.
  • Prohibit the issuance of a takeoff clearance during an airplane’s taxi to its departure runway until after the airplane has crossed all intersecting runways.
  • Revise Federal Aviation Administration Order 7110.65, "Air Traffic Control," to indicate that controllers should refrain from performing administrative tasks, such as the traffic count, when moving aircraft are in the controller’s area of responsibility.

The U.S. aviation agency ticked off their actions for safer takeoffs initiated since last August in response to the NTSB’s initial recommendations. They took the form of Safety Alert for Operators (SAFO) and Information for Operator Bulletins regarding safety and information alerts. The FAA also issued enhanced standards for taxiway centerline and hold line markings where a taxiway approaches a runway, and a Certification Alert recommending a "best practice" for notice of construction changes on an airfield. Starting in October 2007, the FAA will eliminate local NOTAMs and will store, number and distribute all NOTAMs throughout the United States. Meanwhile, the FAA looks favorably at Electronic Flight Bags, especially lower cost ones in development.

The FAA had no immediate comment on the five additional safety recommendations from the NTSB. In a statement, Comair President Don Bornhorst said he would work with the NTSB and the FAA to address the proposed changes.

National Air Traffic Controllers Association (NATCA) President Patrick Forrey had plenty to say. "We believe this terrible tragedy might well have been prevented had there been a second controllers in this facility on this shift. NATCA’s long-held position is there should NEVER be one controller working by himself or herself. Ever. This was a deadly mistake by the FAA in not properly staffing this facility according to the agency’s own requirements, and exemplifies what can happen when you try to operate an inherently governmental safety service like a business," said Forrey.

"Bottom line: The FAA created a situation that might have ended very differently had they followed their own policy of appropriate staffing levels. The FAA failed in their responsibility to provide every possible safeguard to the flying public….They required this man to perform the tasks of two controllers. This lone controller had no opportunity to act as a safety net, to turn a tragedy into an "almost tragedy" as controllers do so many times across this country. The agency put him in an impossibly difficult situation of performing two critically important jobs by himself to save a buck," he charged.

Under questioning by Safety Board members, the investigators could not explain why the flight deck crew missed the numerous cues surrounding their fatal decision to take off from the wrong runway. Joseph Sedor, the NTSB’s investigator-in-charge, said "there was not one specific bit of information to say what caused them to do what they do, to say what caused this accident…We may never know." Another investigator said "there is no good answer. They may have been busy, but that is no excuse." The staff said there was no sign that the crew was confused. "If they had asked the controller, he would have told them that they were in the wrong place."

NTSB Chairman Rosenker said "this was not a simple investigation because we were dealing with complex human performance issues…Accidents involving human performance can present a difficult challenge as investigators strive to understand the factors that explain why an error occurred, such as inattention.

"In many cases, a probe of human error does not yield a singular cause because available data is often not specific or testable as when examining aircraft component failure," Rosenker added.

Simply put, said Board Member Debbie Hersman, "this accident has led us into the briar patch of human behaviour. It’s clear this crew made a mistake. Their heads just weren’t in the game here. The issue is what enabled them to make this mistake?"