The National Transportation Safety Board (NTSB) said testing showed Autopilot could not have been functioning in an April 17 Tesla Model S fatal crash near Houston, Texas because a key feature could not have been in use, according to a preliminary report released Monday. Local police have said they believed the crash occurred with no one in the driver's seat, raising questions about Tesla's driver assistance systems.
The NTSB said the vehicle was equipped with "Autopilot" – Tesla’s advanced driver assistance system – and the system requires both Traffic Aware Cruise Control and Autosteer systems to be engaged.
Tesla and police in Texas did not respond to a request for comment.
NTSB said its tests of an exemplar car at the crash location showed that Traffic Aware Cruise Control could be engaged but that Autosteer was not available on that part of the road.
Tesla says Traffic-Aware Cruise Control matches a car's speed of to that of surrounding traffic, while Autosteer assists in steering within a clearly marked lane.
The NTSB also said footage from the owner’s home security cameras showed the owner entering the driver’s seat and the passenger entering the front passenger seat.
The crash in Spring, Texas, killed the 59-year-old owner, William Varner, an anesthesiologist, and a 69-year-old passenger.
The Tesla traveled 550 feet before departing the road on a curve, driving over the curb, and hitting a drainage culvert, a raised manhole, and a tree, the NTSB said.
It said the crash damaged the front of the car’s high-voltage lithium-ion battery case, where a fire started. The fire destroyed the car, including the onboard storage device.
The NTSB said the car’s restraint control module, which can record data associated with vehicle speed, belt status, acceleration, and airbag deployment, was recovered but sustained fire damage.
The National Highway Traffic Safety Administration is also investigating the crash. NHTSA, the federal agency responsible for vehicle safety, said this week it has opened 28 investigations into crashes of Tesla vehicles, 24 of which remain active, and at least four, including the fatal Texas accident, have occurred since March.