New Dulles Aerotrain shuts down for a while on 2nd day of service

On its second day operating, a new underground train that whisks travelers to their gates at Dulles International Airport went out of service for 41 minutes.

The unmanned AeroTrain shut down at 9:25 p.m. Wednesday after control room operators detected an open door in a tunnel between two of the four stations. The door, leading to a maintenance corridor, had mistakenly been left open by a firefighter responding to an unrelated alarm, said Robert Yingling, a spokesman for the Metropolitan Washington Airports Authority, which operates Dulles. He said the train's safety procedures required the system to shut down in the event that passengers in the tunnel were in danger.

The airport ran mobile lounges from the main terminal to the gates during the delay; about half of the diesel-powered shuttle buses remain in service.

The mishap prompted United Airlines, the dominant carrier at Dulles, to hold three flights, with the longest delay 11 minutes. Six passengers missed their connections, Yingling said.

The $1.5.billion AeroTrain went into service Tuesday after almost nine years of construction.

"All of the safety mechanisms [on the train] worked" Yingling said. "This is certainly something we take very seriously, and we're going to investigate how we can handle these incidents more smoothly in the future."

-- Lisa Rein