The National Transportation Safety Board has identified staffing procedures as a central concern in its probe of the LaGuardia Airport accident that killed two Air Canada pilots Sunday night.
NTSB Chair Jennifer Homendy said two air traffic controllers were in the tower when the Air Canada Express jet struck a Port Authority fire truck. At least one controller was performing multiple duties, she said, but she cautioned against singling out individuals and emphasized the problem appears systemic: “This is a heavy workload environment.”
Homendy noted that on the midnight shift it is often standard for only two controllers to cover duties normally handled by more people. Given LaGuardia’s dense operations, she questioned whether that practice is appropriate there and said the NTSB will examine it. On duty were a local controller, responsible for active runways and immediate airspace, and a controller in charge, who oversees overall safety. The controller in charge also was acting as clearance delivery, which issues departure clearances. The NTSB has received conflicting information about whether one of the controllers was also serving as ground controller, who manages vehicle movements on taxiways.
The agency’s air traffic control team has raised concerns about the midnight shift and staffing levels for years. While investigators have no indication that fatigue played a role in this crash, the midnight shift has been a recurring focus in past probes. Transportation Secretary Sean Duffy said Monday that LaGuardia’s staffing is “relatively good”: the airport wants 37 controllers, there were 33 on staff, and seven more were in training.
Investigators recovered the cockpit voice recorder and sent it to the NTSB lab for analysis. NTSB investigator Doug Brazy summarized the last three minutes of audio: the flight crew completed the landing checklist and alerts showed the aircraft was nearing the runway. An unknown airport vehicle transmitted to the tower but its call was “stepped on”—overlapped and interrupted—by another transmission. Firefighters told the tower they wanted to cross the runway while responding to reports of fumes from a United Airlines plane; controllers granted the request.
According to the recording, controllers told the truck to stop nine seconds before the recording ended. The fire truck did not have a transponder, Homendy said. The tower can use an Airport Surface Detection System, Model X (ASDE-X), to track movement on the airfield, but it did not produce an alert in this case. Preliminary analysis from the NTSB tech center indicates ASDE-X failed to generate an alert because vehicles were merging and unmerging near the runway, preventing the system from creating a high-confidence track.
In the final seconds captured on the recorder, it sounds like the aircraft touched down eight seconds before the end of the clip; six seconds out the first officer transferred control to the captain; and four seconds out tower controllers again told the firefighters to stop.
Homendy stressed that findings are preliminary and subject to verification. Investigators still do not know who made the transmission that was stepped on, why a controller remained on duty after the collision, whether the firefighters heard the stop commands, whether the pilots saw the truck, or whether there was confusion in the cockpit. “We rarely, if ever, investigate a major accident where it was one failure,” Homendy said, noting that aviation safety depends on multiple layers of defense and that many things likely went wrong. The NTSB will continue examining staffing practices and other factors as the investigation proceeds.