A B757's autopilot computer servo circuit breaker popped at 3;500 ft; the number two autopilot disco...

Attributes
ACN	955289
Time
Date	201106
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Route In Use	SID ZZZ
Flight Plan	IFR
Component
Aircraft Component	Autoflight System
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Flight Instructor Flight Crew Flight Engineer Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 11000 Flight Crew Type 6000
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Engineer Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 80 Flight Crew Total 15500 Flight Crew Type 3500
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Departed the airport on a clear sunny day via an RNAV SID. Had just cleaned up the aircraft and were proceeding to the initial waypoint on the RNAV departure off runway 27. The center autopilot was engaged with LNAV and VNAV selected. We were climbing normally through about 3;500 MSL (2;500 AGL) to 10;000 MSL at about one mile prior to initial waypoint when we got an aural warning horn and an autopilot warning light indicating that the autopilot had malfunctioned and or disconnected. The aircraft immediately pitched up about 10-15 degrees above the normal climb pitch and quickly lost about 30 KTS (230 down to 200 KTS) of airspeed before I ensured the autopilot was disconnected; leveled the wings and lowered the nose back to a normal pitch attitude. As we recovered and made sure the aircraft was flying normally without the autopilot; we inadvertently missed the left turn as we passed the waypoint on the departure. We started the turn about a mile to a mile and a half late just as the departure controller queried us. There were no traffic conflicts. We later found a popped computer servo circuit breaker for the center autopilot and we wrote up the malfunction in the logbook. The rest of the flight was uneventful.

Original NASA ASRS Text

Title: A B757's autopilot computer servo circuit breaker popped at 3;500 FT; the number two autopilot disconnected with the autopilot warning light and the aircraft pitched up 10-15 degrees causing a 30 KT airspeed loss.

Narrative: Departed the airport on a clear sunny day via an RNAV SID. Had just cleaned up the aircraft and were proceeding to the initial waypoint on the RNAV departure off Runway 27. The center autopilot was engaged with LNAV and VNAV selected. We were climbing normally through about 3;500 MSL (2;500 AGL) to 10;000 MSL at about one mile prior to initial waypoint when we got an aural warning horn and an autopilot warning light indicating that the autopilot had malfunctioned and or disconnected. The aircraft immediately pitched up about 10-15 degrees above the normal climb pitch and quickly lost about 30 KTS (230 down to 200 KTS) of airspeed before I ensured the autopilot was disconnected; leveled the wings and lowered the nose back to a normal pitch attitude. As we recovered and made sure the aircraft was flying normally without the autopilot; we inadvertently missed the left turn as we passed the waypoint on the departure. We started the turn about a mile to a mile and a half late just as the Departure Controller queried us. There were no traffic conflicts. We later found a popped computer servo circuit breaker for the center autopilot and we wrote up the malfunction in the logbook. The rest of the flight was uneventful.

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.

A B757's autopilot computer servo circuit breaker popped at 3;500 ft; the number two autopilot disconnected with the autopilot warning light and the aircraft pitched up 10-15 degrees causing a 30 KT airspeed loss.