B757 flight crew experiences air data computer failure due to apparent faulty wiring shortly after t...

Attributes
ACN	921509
Time
Date	201012
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Component
Aircraft Component	Air Data Computer
Person 1
Function	Pilot Not Flying Check Pilot Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 24000 Flight Crew Type 9000
Person 2
Function	First Officer Pilot Flying
Experience	Flight Crew Last 90 Days 70 Flight Crew Total 12000 Flight Crew Type 3000
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

On climb out at approximately 600 feet first officer's flight director bars failed and vs and airspeed indicator began to give erroneous indications. This was followed by several EICAS messages: mach trim speed; rudder ratio; airspeed. The first officer pitched down and applied max thrust. As I saw him do this I looked at his instruments and saw they disagreed with mine. I verified my airspeed indicator was working properly by comparing to the standby airspeed indicator and took control of the aircraft. We leveled off at 800 feet to try to stay below the bases and declared an emergency. Flap 5 speed limit may have been exceeded momentarily. Tower let us circle to land on the departure runway . Aircraft was difficult to control on final as trim was unresponsive. Normal flap 30 landing made without any additional problems.

Original NASA ASRS Text

Title: B757 flight crew experiences Air Data Computer failure due to apparent faulty wiring shortly after takeoff; resulting in loss of First Officer's pitot static instruments and associated EICAS warnings. The Captain took control and returned visually for landing on the departure runway.

Narrative: On climb out at approximately 600 feet First Officer's flight director bars failed and VS and airspeed indicator began to give erroneous indications. This was followed by several EICAS messages: mach trim speed; rudder ratio; airspeed. The First Officer pitched down and applied max thrust. As I saw him do this I looked at his instruments and saw they disagreed with mine. I verified my airspeed indicator was working properly by comparing to the standby airspeed indicator and took control of the aircraft. We leveled off at 800 feet to try to stay below the bases and declared an emergency. Flap 5 speed limit may have been exceeded momentarily. Tower let us circle to land on the departure runway . Aircraft was difficult to control on final as trim was unresponsive. Normal flap 30 landing made without any additional problems.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B757 flight crew experiences air data computer failure due to apparent faulty wiring shortly after takeoff; resulting in loss of first officer's pitot static instruments and associated EICAS warnings. The captain took control and returned visually for landing on the departure runway.