Changing auto brake setting during roll out
Joined: Nov 1999
Aviation Qualifications: ATPL
Posts: 3,150
Likes: 744
From: UK
What I am aluding to is that no proper professional pilot will take their eyes off the situation outside unless the aircraft is fully under control and the conditions are benign. When it is fully under control, looking down (or up) for a second to change a switch.......is it such a big risk?
If it is, just ask the other pilot for what you want.
Hard hat on to deflect incoming...................
Joined: Nov 2006
Posts: 377
Likes: 0
From: In the real world
This happens all the time in my airline, the 75/76 auto brakes are very smooth so modifying the decel rate is almost standard practice. Regarding taking your eyes off the runway well no probs as the auto brake selector is in PM’s area of responsibility.
I love the ‘madness’ shouts, they make me laugh and just show cultural differences between airlines.
I love the ‘madness’ shouts, they make me laugh and just show cultural differences between airlines.
Joined: Nov 1998
Posts: 2,135
Likes: 77
From: 🇬🇧🇪🇸
I was a passenger in a FR 738 some time back when the crew inadvertently selected what I believe to be RTO during the landing roll out. The sudden decelaration was enough to propel me into the seatback in front, I sustained a minor injury to my right hand while trying to save myself. Very unpleasant and no explanation from the flightdeck. Senior Cabin Crew was in the flightdeck during disembarkation asking WTF was going on..
Joined: Sep 2011
Posts: 352
Likes: 148
From: FL390
I don't do it - unpleasant jolt on the 787 if you go twiddling the autobrake knob, which isn't conveniently located to begin with. Especially when you have the deceleration scale in the HUD, why would you want to? Do the performance calculation properly, land it in the right place, and leave the autobrake in until taxi speed.
Joined: Oct 2001
Posts: 194
Likes: 2
From: MAN
B757 FCOM Systems:
”Autobrake application occurs slightly after main gear touchdown. Deceleration is
limited until the pitch angle is less than one degree, then deceleration increases to
the selected level. The deceleration level can be changed (without disarming the
system) by rotating the selector.”
”Autobrake application occurs slightly after main gear touchdown. Deceleration is
limited until the pitch angle is less than one degree, then deceleration increases to
the selected level. The deceleration level can be changed (without disarming the
system) by rotating the selector.”
Joined: Sep 2012
Posts: 261
Likes: 42
From: Europe
I don't mean to step on toes, and I understand autobrakes are a tool to be used and probably nice to have, especially the bigger and heavier the type gets. But I agree with the notion of why go through the trouble of fiddling with selector knobs or buttons when there's two big pedals at your feet you can use? It might not be as accurate as the computers can do it, but I think I managed about 10 years of flying so far without giving the passengers any injuries or bruises from their seatbelts (my type does not have autobrakes).
Taken to extremes, next up we will have accidents because pilots don't know how to brake with care anymore
.
Taken to extremes, next up we will have accidents because pilots don't know how to brake with care anymore
.
Joined: Jan 2006
Posts: 2,205
Likes: 0
From: US
Wait a minute, you have your feet on the rudder pedals and you’re fiddling with a switch down FO’s knee to modulate the braking?!? We’re doomed.
The car radio analogy? Anyone think fiddling with a speed control setting on the dash screen is a great idea when you have your foot of the accelerator?? Can you do it? Sure. Great idea? Debatable.
The car radio analogy? Anyone think fiddling with a speed control setting on the dash screen is a great idea when you have your foot of the accelerator?? Can you do it? Sure. Great idea? Debatable.
Joined: Mar 2006
Posts: 1,115
Likes: 86
From: England
‘It’ (radio or AB) can be changed; should it be, is it necessary.
Is there less distracting alternative - aircraft, yes, manual braking.
Re bulletins:
Who writes / authorises the bulletins ?
What do they say, why, to what purpose ?
Who holds the final safety responsibility for the bulletin ?
… for the aircraft … You ?
Is there less distracting alternative - aircraft, yes, manual braking.
Re bulletins:
Who writes / authorises the bulletins ?
What do they say, why, to what purpose ?
Who holds the final safety responsibility for the bulletin ?
… for the aircraft … You ?
Joined: Mar 2006
Posts: 2,633
Likes: 137
From: USA
I've seen somebody disengage the AB via the pushbutton on the panel (A320) during rollout. What if he'd selected max instead? Would anyone die? Probably not, but there's some risk of injury with max AB, I assume.
There's nothing expressly prohibiting it, but it just seems like way more work than using the pedals. Not worth me getting worked up over it though.
There's nothing expressly prohibiting it, but it just seems like way more work than using the pedals. Not worth me getting worked up over it though.
Joined: Oct 2015
Posts: 279
Likes: 3
From: 43N
We are to disconnect autobrakes via manual braking, not using the switch. I believe that is still required across all fleets at our company. I can understand directing the PM to change the auto brake setting during the approach because of unanticipated conditions.
I can not understand doing that on the runway. So the Captain is landing and now decides to: take his eyes off the runway, look over to the autobrake panel, take his right hand off the TL’s and reach across the cockpit to deselect, select, or increase the AB setting. Or one may say, well no, he directs his FO to do the action. So now that FO is presented with a command from the Captain he most likely has never encountered nor anticipated and is to complete during a critical phase.
I can easily imagine a hundred things which could go wrong. Isn’t our job to manage the threats inherent in our occupation not add to them?
I can not understand doing that on the runway. So the Captain is landing and now decides to: take his eyes off the runway, look over to the autobrake panel, take his right hand off the TL’s and reach across the cockpit to deselect, select, or increase the AB setting. Or one may say, well no, he directs his FO to do the action. So now that FO is presented with a command from the Captain he most likely has never encountered nor anticipated and is to complete during a critical phase.
I can easily imagine a hundred things which could go wrong. Isn’t our job to manage the threats inherent in our occupation not add to them?
Joined: Feb 2013
Posts: 17
Likes: 1
From: 60 north
Doobler China
It was either " Madness" or " Moronic", so I say figured the former was less insulting.
On a technical level , there is no advantages ( on the 737, anyway) and only a heap of hurt if getting it wrong.
The fact that a bunch of test pilots with zero line experience has gotten away with using it , and does not see the potential for a disaster in our hands , repeating it a few million times a year , instead of proper conservative breaking , means nothing. In my book!
Another little thing on the 737 the autobrake some times does not arm. All you do then is go to zero for a few seconds, then back to desired selection , and voila, it arms. Doing that midfield at 100kts eats rwy!?
Anyway
I recall doing a thing or two some times back, when the "culture" was somewhat more relaxed. Sure we had fun , and we were good, but most of the time lucky.
Buzzing my Brothers farm on empty trips at 100 feet comes to mind,,,
You all have fun now
Cpt B
On a technical level , there is no advantages ( on the 737, anyway) and only a heap of hurt if getting it wrong.
The fact that a bunch of test pilots with zero line experience has gotten away with using it , and does not see the potential for a disaster in our hands , repeating it a few million times a year , instead of proper conservative breaking , means nothing. In my book!
Another little thing on the 737 the autobrake some times does not arm. All you do then is go to zero for a few seconds, then back to desired selection , and voila, it arms. Doing that midfield at 100kts eats rwy!?
Anyway
I recall doing a thing or two some times back, when the "culture" was somewhat more relaxed. Sure we had fun , and we were good, but most of the time lucky.
Buzzing my Brothers farm on empty trips at 100 feet comes to mind,,,
You all have fun now
Cpt B
Joined: Jan 2006
Aviation Qualifications: CPL
Posts: 1,410
Likes: 46
From: Between a rock and a hard place
On a technical level , there is no advantages ( on the 737, anyway) and only a heap of hurt if getting it wrong.
Joined: Jan 2006
Aviation Qualifications: CPL
Posts: 1,410
Likes: 46
From: Between a rock and a hard place
Nowhere in the 737CL FCTM does it imply fiddling about with the autobrakes after landing, this action surely is a "kludge" at best!