In addition, most systems include multiple passive safety systems that stop operation even if the electronic controller fails.

Again, the controller failed to reach the driver.

If the main controller fails, sub-controllers change to degraded mode in which doors are either completely locked or unlocked and no events are recorded.

Earlier this morning, the controllers tried and failed to get their commands through to the spacecraft.

Investigators have also found that regional controllers failed to relay information about the jet's fuel situation to local controllers.

In an interview, Mr. Maass said that when the helicopter called in for clearance, the controller failed to pass on the information to him.

The mission planners and controllers had failed to realize that when two spacecraft are docked together, they must be considered to be one spacecraft.

But when it re-emerged from behind Venus, controllers failed to detect its signal immediately.

German controllers failed to intercept or locate the stream.