Firebird From Germany, joined Oct 2006, 0 posts, RR: 0 Posted (13 years 9 months 2 weeks 1 hour ago) and read 1563 times:
Can any pilots/ground engineers explain the autopilot system on say a B747.?
I am refering to the mid-air incident London to Nairobi BA flight when that disturbed person tried to kill all on board. What I would like to know is if you grab the control column will it respond? i.e does it disengage the auto pilot and respond???
Just a little confusing as to what happend up there in that flight deck?
I was also wondering if Bryan Ferry was going to bring out a new version of I'm all shook up! (He was on that flight)......sorry could not resist?
Iainhol From , joined Dec 1969, posts, RR:
Reply 1, posted (13 years 9 months 1 week 6 days 21 hours ago) and read 1501 times:
It is my understanding on the side of the yoke they have a button that needs to be pressed twice to disengage the autopilot, which I could see easily happening with a goings on in that cockpit. Also please note when you say mid-air, most people think of a mid-air collision, saying during flight, or while in cruise would not confuse as many!
Boomer From United States of America, joined May 1999, 102 posts, RR: 0
Reply 2, posted (13 years 9 months 1 week 6 days 11 hours ago) and read 1464 times:
The autopilot disconnect buttons that Iain refers to are provided to permit a graceful uncoupling of the autopilot and assumption of manual control. The idea is that the pilot would have his/her hands on the column while the autopilot lets go and transfers control to the pilot.
I believe there are also load cells in the column mechanism (I don't know if all aircraft have them) that sense a manual force on the column over a preset limit. This will also disconnect the autopilot. The intent is to provide the pilot with instant authority without having to fumble for a button. In case there is a violent pitch, or need to maneuver for traffic avoidance, etc., all the pilot has to do is grab the yoke hard and fly. This is not the most polite way to assume command, but at that point, who cares.
GE From Singapore, joined Mar 2000, 320 posts, RR: 6
Reply 3, posted (13 years 9 months 1 week 6 days 5 hours ago) and read 1435 times:
Well, I guess the cockpit intruder must have pulled the control column really hard in his agony. It must have gone over the preset limit and disconnected the autopilot. Thank you for that point, Boomer.
Dash8tech From United States of America, joined Jul 1999, 732 posts, RR: 5
Reply 4, posted (13 years 9 months 1 week 6 days 4 hours ago) and read 1424 times:
Here at Horizon we fly the Dash 8 and F-28 a/c. Both entirely different A/P systems. The Dash 8 has an A/P disconnect button on the yoke and it recquires just one push (another push to clear the advisor message) to disengage the A/P. The Dash 8 also has a TCS (touch ((tactile the French like to say)) control steering). You push the TCS button, maneuver the a/c, then release it and the A/P goes back to where it was. Handy for TCAS advisories etc.
The F-28 is plain manual over-ride. Move the yoke and it'll do what you want it to do.