Correct way to abort T/O in 744 ?

[JSACKS 0]

What is the correct way to disconnect the power in aborting a t/o in the Queen? I usually have to unclick the A/T button first and then pull back the throttles. Is this correct for the sim?(Just curious, but how does it work in real life?)Jonathan

[victorlima01 2]

Not sure but I suspect in real life once thrust is set the autothrottle enters "HOLD" mode and thus all you need to do is manually push the throttles back all the way to idle, which automatically disconnects the autothrottle servos even though the autothrottle remains armed. After that just sit back and watch autobrakes do the rest or you can also give a little reverse thrust to help in the braking action. Might be a good idea to steer the aircraft as well to maintain rwy centerline!Anyway, read Robert's type course rating 3 which talks specifically of that. The answer lies there, somewhere inbetween exclamaiton points! Best Regards,Victor Limahttp://www.precisionmanuals.com/images/forum/800driver.jpg

[Qavion 19]

"thus all you need to do is manually push the throttles back all the way to idle, which automatically disconnects the autothrottle servos even though the autothrottle remains armed."In HOLD mode, the autothottle SERVO (singular) is already disconnected ;)One servomotor drives all 4 thrust levers via a "clutchpack".Cheers.Q>

[JSACKS 0]

Thank you for the replies.I have an additional question:Suppose there is a significant crosswind when aborting. If I set AUTOBRAKES and they kick in when I retard the throttles, how do I use the rudder to keep ground steering centered without disengaging the autobrakes?Jonathan

[Qavion 19]

"how do I use the rudder to keep ground steering centered without disengaging the autobrakes?"Not sure what you mean, Jonathan... Your pedals should have two separate mechanisms... one for braking and one for steering. 1. For braking, you push on the tops of both pedals with your toes(the pedals are hinged at the bottom causing the pedals to tilt) and...2. For steering, you push the applicable pedal in a linear fashion to make the pedals move fore-aft in a horizontal plane.On the real aircraft, you have a pedal fore-aft adjustment to compensate for leg length which may help you to apply forces in the correct directions on the pedals.Hope this helps.Cheers.Q.

[Gary A 8]

These procedurers are for a 767 but may be usefull.http://www.smartcockpit.com/

[jon b 2,041]

Jonathan,1)close the thrust leavers aggressivley,and hit the A/T disconnect switch,if in HOLD its not strictly required but we always do to cover the case when it is required,it save you having to think in a hurry.2)manually deploy the speed brake. again this should already be happening automatically but at the moment at least its a company procedure3)use full symetrical reverse as required4)confirm RTO function of the autobrakes, less than 85kts ground speed it wont have engaged.5)bring the aircraft to a stop,set the parking brake,PA to the cabin to remain seated,if applicable,this should stop the cabin crew from initiating an evacuation,and call for an appropriate QRH checklist.As first officer/PNF ,(its all ways the capt who aborts in our company operations) you would monitor the actions, confirm RTO autobrake,tell ATC you`re stopping,and call decreasing airspeeds 100 80 60,and 50 kt ground speed.If it was a high speed reject you are going to have smoke coming off the brakes and soon find yourself surrounded by fire trucks,its all very dramatic! having done one a few years ago at LHR from about 110ktsYou would then need to check your graphs to see how long to wait before attempting another takeoff,chances are you wont be using that aircraft again today!cheersJon

[Guest s_L_Y_F_a]

>2)manually deploy the speed brake. again this should already>be happening automatically but at the moment at least its a>company procedure.Should happen automatically? I thought the crew has to deploy them since they do not get armed before takeoff. Or am I missing something :-hmmm

[Qavion 19]

They will deploy automatically when you pull up on the reversers... not prior to this.Cheers.Q>

[JSACKS 0]

Dear Q:My pedals do indeed have both of those mechanisms. But the reason I asked the question is because it was my understanding from a while back that if Autobrakes are engaged, just touching a rudder pedal could cause them to disengage. Therefore, I was wondering how to use the rudder pedals to steer for a high speed abort if autobrakes have already been engaged. Maybe I didn't understand correctly.Thanks to you and others for jumping into this thread.JS

[JSACKS 0]

Jon:I didn't realize you would also use reversers. This could be tricky if an engine has gone out, no? Would not Autobrakes suffice even for a MGTOW abort?Jonathan

[jon b 2,041]

jonathan,the first officer should call inboards or outboards, you then select all 4 to idle but only use a symetrical pair. reverse is used as you need all the stoping power you can get, a RTO is a very aggressive drill.performance calculations use reverse thrust for wet runways but not dry,but it is all ways used.As Q mentions selecting idle reverse will automatically deploy the speedbrakes, either in a RTO or a landing, wether they are armed or not.cheersjon

[JSACKS 0]

Jon:OK, mate, thanks again.Good thread, thanks all!Jonathan

[Qavion 19]

"it was my understanding from a while back that if Autobrakes are engaged, just touching a rudder pedal could cause them to disengage."A misunderstanding, JS... They should only disengage if you touch the tops of the rudder pedals.Cheers.Q>

[JSACKS 0]

Ah, OK, thanks. So I still need to be careful how I angle my feet !Jonathan