Federal investigators ruled out all possible driver and vehicle factors in the 2017 fatal collision of a motorcoach and transit bus in Flushing, New York. Another factor could not be excluded: the possibility that a driver’s stainless steel Thermos bottle fell between the brake and accelerator pedals.
The jammed bottle may have caused unintended acceleration as the driver frantically applied the brakes while the motorcoach approached traffic, the National Transportation Safety Board reported on Feb. 21.
Three people were killed on Sept. 18, 2017, when a 2015 MCI motorcoach, operated by Dahlia Group Inc. of Flushing, collided with a 2015 New Flyer XD40 operated by New York City Transit Authority at an intersection along New York State Route 25A. The motorcoach, occupied only by the driver, ran a red light and was accelerating as it approached the intersection, striking the transit bus while traveling at about 60 mph.
NTSB investigators ruled out driver factors in the collision, stating they “found no evidence that his experience, training, route familiarity or pre-crash activities were factors.” Investigators also ruled out sleep deprivation, obstructive sleep apnea, medical conditions, medications and cell phone distraction.
As for the MCI motorcoach, “NTSB investigators considered whether a mechanical or electrical issue could have resulted in unintended acceleration but found no evidence of a runaway engine, electrical malfunction, brake fade or brake deficiencies, or issues with an open throttle.”
Investigators found the metal Thermos on the floor near the control pedals. There was no physical evidence of contact on the bottle or pedals, but investigators found that “it was possible to position the Thermos beneath and between the pedal controls such that it prevented brake application while depressing the throttle.” Investigators recreated the possible predicament with a similar bottle in another motorcoach of the same model.
Therefore, the report continues, “The National Transportation Safety Board determines that the probable cause of the Flushing, New York, crash was the driver’s unintended acceleration of the motorcoach and inability to brake for reasons that could not be conclusively determined from the information available.”
The ‘should haves’
The NTSB report suggested two emergency measures the motorcoach driver could have taken to prevent or mitigate the crash:
“The driver could have turned off the engine by pulling out the key—which would have terminated propulsion and decreased vehicle speed. The driver could have shifted into neutral and applied the parking brakes—which would have caused the air inside the drive axle brake chambers to exhaust, allowing the spring brake actuators to automatically apply the brakes via a mechanical means, thus slowing the vehicle.”