Narrative:

On gear retraction the captain's flight director bars disappeared. I cycled the F/D switch but they did not return. The first officer's bank steer bar disappeared but his pitch bar was in view. My FMA and the first officer's FMA did not agree and all of the lights on the mode control panel were flickering on and off as if being pushed. As we were handed off to departure we were given an altitude and heading change. The heading read 251 and was uncontrollable. The altitude had been preset to 5;000 but read 2;300 and was uncontrollable. The airspeed read 6 and was uncontrollable. The orange airspeed bug slewed randomly from 162 KTS to 350 KTS before settling on 350 KTS for the duration of the flight. As we were dealing with this the autopilot warning sounded and illuminated. I asked the first officer why he had engaged the autopilot and he stated that it had engaged uncommanded and that he was disengaging it (the autopilot engaged uncommanded at least 10 times during the 14 minute flight). Concerned about flight control issues and a potential electrical fire I declared an emergency with ATC; sent a message to dispatch stating our intentions to return to ZZZ; and called the purser to give him a cabin advisory. An uneventful approach and landing ensued and after being inspected by rescue we then proceeded to the gate under fire escort. All appropriate checklists were accomplished.

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Original NASA ASRS Text

Title: B757 flight crew experiences a MCP malfunction at lift off that causes erratic changes to all parameters controlled by the Mode Control Panel. This malfunction included numerous uncommanded engagements of the autopilot. After declaring an emergency the flight returns to departure airport for a raw data ILS in IMC to a safe landing.

Narrative: On gear retraction the captain's flight director bars disappeared. I cycled the F/D switch but they did not return. The First Officer's bank steer bar disappeared but his pitch bar was in view. My FMA and the First Officer's FMA did not agree and all of the lights on the mode control panel were flickering on and off as if being pushed. As we were handed off to Departure we were given an altitude and heading change. The heading read 251 and was uncontrollable. The altitude had been preset to 5;000 but read 2;300 and was uncontrollable. The airspeed read 6 and was uncontrollable. The orange airspeed bug slewed randomly from 162 KTS to 350 KTS before settling on 350 KTS for the duration of the flight. As we were dealing with this the autopilot warning sounded and illuminated. I asked the First Officer why he had engaged the autopilot and he stated that it had engaged uncommanded and that he was disengaging it (the autopilot engaged uncommanded at least 10 times during the 14 minute flight). Concerned about flight control issues and a potential electrical fire I declared an emergency with ATC; sent a message to Dispatch stating our intentions to return to ZZZ; and called the Purser to give him a cabin advisory. An uneventful approach and landing ensued and after being inspected by rescue we then proceeded to the gate under fire escort. All appropriate checklists were accomplished.

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.