Didn't have the strength to pull.
Originally Posted by
fox niner
This one crossed my mind as well. I have personally experienced something like this in a 777. AP was engaged all the time at the gate, and we found out it was engaged when we did the flight controls check after engine start. This disengaged the AP due to the control forces needed, and the wailer went off when it disengaged.
In our case it turned out that maintenance had engaged it to do some work, and had left it engaged, and left the cockpit when we arrived before the flight.
Didn’t AirFrance attempt a takeoff with the AP engaged in Port Harcourt with a 777? Thought they did…
EDIT
Found it. A/P engaged takeoff attempt:
Incident: Air France B773 at Lagos on Jan 12th 2010, rejected takeoff
Good post.
No pilot would carry on belting down the runway at 200+ knots without pulling like mad. Something was physically stuck and it took precious time to overcome.
"
The captain explained later, that he rejected takeoff because he felt the elevators were blocked when he pulled for rotation."
"
On February 24th 2009 Boeing had advised operators about the possibility of the manual but unintentional engagement of the autopilot, which significantly increases control pressures needed to achieve rotation of the aircraft. On January 22nd 2010 released a service bulletin advising of a new autopilot software version, which prevents the engagement of the autopilot during the takeoff run. Air France has since applied the service bulletin to all their Boeing 777s. The FAA issued an airworthiness directive mandating the new software to be installed within 90 days following April 1st 2010."