B777-200 rejected takeoff after the flight crew realized that the autopilot had been engaged.

Attributes
ACN	763141
Time
Date	200711
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Controlling Facilities	tower : zzz.tower
Operator	common carrier : air carrier
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 240 flight time total : 14000 flight time type : 3000
ASRS Report	763141
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 210 flight time total : 10000 flight time type : 1000
ASRS Report	763144
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : master warning other flight crewa other flight crewb
Resolutory Action	flight crew : rejected takeoff
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

On takeoff roll at approximately 50 KTS; copilot pushed control wheel forward and felt abnormal resistance. Master warning illuminated and warning horn sounded. Autoplt disengaged message illuminated. A low speed abort was performed. After consultation with maintenance; it was determined that an inadvertent engagement of the autoplt was at fault. Autoplt showed normal on the system maintenance page. With maintenance concurrence; flight was continued and all system operated normally. Since flight controls were checked to full deflection shortly prior to being cleared onto the runway; the only time the autoplt could have engaged would have been in the last 60 seconds prior to takeoff.

Original NASA ASRS Text

Title: B777-200 REJECTED TKOF AFTER THE FLT CREW REALIZED THAT THE AUTOPILOT HAD BEEN ENGAGED.

Narrative: ON TKOF ROLL AT APPROX 50 KTS; COPLT PUSHED CTL WHEEL FORWARD AND FELT ABNORMAL RESISTANCE. MASTER WARNING ILLUMINATED AND WARNING HORN SOUNDED. AUTOPLT DISENGAGED MESSAGE ILLUMINATED. A LOW SPD ABORT WAS PERFORMED. AFTER CONSULTATION WITH MAINT; IT WAS DETERMINED THAT AN INADVERTENT ENGAGEMENT OF THE AUTOPLT WAS AT FAULT. AUTOPLT SHOWED NORMAL ON THE SYS MAINT PAGE. WITH MAINT CONCURRENCE; FLT WAS CONTINUED AND ALL SYS OPERATED NORMALLY. SINCE FLT CTLS WERE CHKED TO FULL DEFLECTION SHORTLY PRIOR TO BEING CLRED ONTO THE RWY; THE ONLY TIME THE AUTOPLT COULD HAVE ENGAGED WOULD HAVE BEEN IN THE LAST 60 SECONDS PRIOR TO TKOF.

Data retrieved from NASA's ASRS site as of January 2009 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.