Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Distraction; Troubleshooting
Aircraft Equipment Problem Critical
Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; General Maintenance Action; General Declared Emergency
Human Factors; Aircraft
While in cruise at FL390 both ECCs failed as well as the additional failure of all limit protection; Captain's airspeed; Hydraulic A system pressure indication; and radar disagree. We held at an en route fix in radar contact and called Maintenance Control through Dispatch; advised ATC of our system losses; and declared an emergency. We then briefed the flight attendants; (no passengers on board) and did all normal and abnormal checklists. I then gave the First Officer pilot flying duties and we returned to our departure airport where we made an uneventful landing and filled out the logbook.
The flight crew of an air carrier aircraft suffered multiple system indication failures; declared an emergency; and returned to their departure airport for maintenance.