speedracer1407
Posts: 330
Joined: Fri Dec 24, 2004 4:19 pm

Arming Autobrakes

Tue Oct 17, 2006 11:18 am

I wasn't sure how to title this thread.

It's my understanding that autobrakes are armed before touchdown, likely in some checklist WELL before touchdown. Is it simply a matter of ensuring that the autobrake selector is set at the desired setting? Or is there something more to it, like a separate button that arms the system independently of the selector.

Also, how does autobrake selection work in situations when the pilot needs more or less braking than expected.

I seem to recall a pilot in another post suggesting that, if the ABS was set to "2" he could simply flick it to 3 during the landing rollout to expedite deceleration for a quickly approaching turnoff. Am I remembering this correctly?

Moreover, can the ABS system be used after touchdown if it hasn't been preset? I'm imagining a scenario in which a pilot is practicing touch and goes, and therefore has the ABS set to off. He touches down, and at that moment, an engine lets go, or some other serious failure occures. Can he simply flick the ABS over to "max," or does he need to apply manual braking?

This scenario is, of course, predicated on the idea that it would be wise/legal to jump on the brakes during a touch and go. I have no idea whether it is a good idea to do so, or even legal. Regardless, I'm curious about whether or not ABS can be activated once the plane has touched down with the system turned off.

thanks for any replies.
O
Dassault Mercure: the plane that has Boeing and Airbus shaking in their boots.
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Arming Autobrakes

Tue Oct 17, 2006 1:22 pm

Quoting Speedracer1407 (Thread starter):
I seem to recall a pilot in another post suggesting that, if the ABS was set to "2" he could simply flick it to 3 during the landing rollout to expedite deceleration for a quickly approaching turnoff. Am I remembering this correctly?

On a Boeing it will Disarm b/t switch positions, and who wants to test whether it will rearm as one is rolling along at 145 kts?

Quoting Speedracer1407 (Thread starter):
Moreover, can the ABS system be used after touchdown if it hasn't been preset? I'm imagining a scenario in which a pilot is practicing touch and goes, and therefore has the ABS set to off. He touches down, and at that moment, an engine lets go, or some other serious failure occures. Can he simply flick the ABS over to "max," or does he need to apply manual braking?

Don't flick switches; bad technique. Use the automation in the manner intended; ie well before landing. If more brake energy is required, go to manual brakes with more pressure. Less? Just tap the brakes, and the autobrakes will disengage.

The function of auto brakes is to start and maintain deceleration at a point faster than humanly (typically) possible. If it's gusty, and you are busy flying the a/c all the way down to taxi speed, that is what ABs are for...
 
IAHFLYR
Posts: 3943
Joined: Sat Jun 25, 2005 12:56 am

RE: Arming Autobrakes

Tue Oct 17, 2006 8:30 pm

Quoting EssentialPowr (Reply 1):
Just tap the brakes, and the autobrakes will disengage.

Can't you run the speed brake closed and then full deflected to release them as well? That tap on the brakes at times is a jolt......bam then gone, very annoying for those who enjoy a nice calm ilde reverse and solid braking!!!  Smile It's like NO you can't make the turn at SF go to the end and round the corner on 2 wheels.......  Embarrassment
Any views shared are strictly my own and do not a represent those of any former employer.
 
IAHFLYR
Posts: 3943
Joined: Sat Jun 25, 2005 12:56 am

RE: Arming Autobrakes

Tue Oct 17, 2006 9:05 pm

Quoting Iahflyr (Reply 2):
run the speed brake closed

Silly dude, he meant spoilers......close the spoilers and then fully deploy them to release the autobrakes!!!  coffee 
Any views shared are strictly my own and do not a represent those of any former employer.
 
PhilSquares
Posts: 3371
Joined: Sun Mar 28, 2004 6:06 pm

RE: Arming Autobrakes

Tue Oct 17, 2006 11:07 pm

Quoting Speedracer1407 (Thread starter):
I seem to recall a pilot in another post suggesting that, if the ABS was set to "2" he could simply flick it to 3 during the landing rollout to expedite deceleration for a quickly approaching turnoff. Am I remembering this correctly?

On the 744, switching the autobrake selector from 2-3 will disarm the autobrakes. With the autobrakes operating, once the selector is taken out of the current position, the autobrakes are disarmed.

Quoting Speedracer1407 (Thread starter):
Moreover, can the ABS system be used after touchdown if it hasn't been preset?

No. However, the rest of your question is somewhat different. On the 744, during touch and go's, as long as the thrust levers aren't vertical or greater, you just abort the maneuver. Stopping isn't a problem at all. If the engines have spooled up, you just continue the takeoff and deal with the problem in the air.
Fly fast, live slow
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Arming Autobrakes

Wed Oct 18, 2006 12:29 pm

Quoting Iahflyr (Reply 2):
It's like NO you can't make the turn at SF go to the end and round the corner on 2 wheels.......

Steve McQween type, baby!!
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Arming Autobrakes

Wed Oct 18, 2006 12:31 pm

Quoting PhilSquares (Reply 4):
On the 744, switching the autobrake selector from 2-3 will disarm the autobrakes. With the autobrakes operating, once the selector is taken out of the current position, the autobrakes are disarmed.



Quoting EssentialPowr (Reply 1):
On a Boeing it will Disarm b/t switch positions, and who wants to test whether it will rearm as one is rolling along at 145 kts?

Is there an echo in here?
 
Max Q
Posts: 5634
Joined: Wed May 09, 2001 12:40 pm

RE: Arming Autobrakes

Thu Oct 26, 2006 2:39 pm

On the 75/6 to disengage the autobrakes you only need to slightly retract the spoilers to smoothly disengage the autobrakes, it does not require full retraction.
The best contribution to safety is a competent Pilot.
 
David L
Posts: 8547
Joined: Tue May 18, 1999 2:26 am

RE: Arming Autobrakes

Thu Oct 26, 2006 6:05 pm

Quoting EssentialPowr (Reply 6):
Quoting PhilSquares (Reply 4):
On the 744, switching the autobrake selector from 2-3 will disarm the autobrakes. With the autobrakes operating, once the selector is taken out of the current position, the autobrakes are disarmed.

Quoting EssentialPowr (Reply 1):
On a Boeing it will Disarm b/t switch positions, and who wants to test whether it will rearm as one is rolling along at 145 kts?

Is there an echo in here?

In defence of PhilSquares, I wasn't sure if you meant the autobrakes are only disarmed while the switch is between settings. It was a slightly modified echo.  Smile
 
PhilSquares
Posts: 3371
Joined: Sun Mar 28, 2004 6:06 pm

RE: Arming Autobrakes

Thu Oct 26, 2006 8:47 pm

Quoting EssentialPowr (Reply 6):
Quoting PhilSquares (Reply 4):
On the 744, switching the autobrake selector from 2-3 will disarm the autobrakes. With the autobrakes operating, once the selector is taken out of the current position, the autobrakes are disarmed.



Quoting EssentialPowr (Reply 1):
On a Boeing it will Disarm b/t switch positions, and who wants to test whether it will rearm as one is rolling along at 145 kts?

Is there an echo in here?

EssentialPowr, having a bad day? What I attempted to do was clairify your post. I can tell you after doing work with and for Boeing, it's one of the things that's tested when an aircraft is delivered. As for the echo, I'd suggest you get your hearing tested!!!
Fly fast, live slow
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Arming Autobrakes

Fri Oct 27, 2006 4:27 am

Phil Squares,

I respectfully submit that the point had been adequately made. I feel people should read other's posts and if they "clarify" them, note that.

I just feel it makes the forum better, and I practice what I preach.

cheers-
 
Bobster2
Posts: 1523
Joined: Mon Jan 17, 2005 3:04 am

RE: Arming Autobrakes

Fri Oct 27, 2006 5:44 am

Quoting EssentialPowr (Reply 10):
should read other's posts and if they "clarify" them, note that.

I believe you meant others' posts. Note how the position of the apostrophe clarifies the meaning.  Smile
"I tell you this, no eternal reward will forgive us now for wasting the dawn." Jim Morrison
 
EssentialPowr
Posts: 1646
Joined: Wed Sep 06, 2000 10:30 pm

RE: Arming Autobrakes

Fri Oct 27, 2006 6:24 am

Quoting Bobster2 (Reply 11):

I believe you meant others' posts. Note how the position of the apostrophe clarifies the meaning.

Absolutely, thank you. "Others" is plural, therefore the possessive form is others'.

Who is online

Users browsing this forum: 737NGFan, eidvm, StTim and 12 guests