737 Jockeys what do you think?
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737 Jockeys what do you think?
Folks,
appreciating your opinion in the following situation:
1. Having a discussion with a collegue about autobrake: He claims, autobrake doenstn make sense, he switches it always off. I claimed that autobrake is a usefull tool. what do you think are the pros and the negative points of using that tool? How do you handle it?
2.Approach, straight in. We had pretty strong tailwind, also the glide intercept on the airport was pretty low, exactly 2000 agl, 7nm out. i preferred to fly not so speedy, leveling of at 13nm to get rid of the 250kt to 210 with the aim in driving the flaps 1 and 10 at 10nm. my collegue meant in the approach, that it was to conservative and we were flying too much level. i just answered, that this approach planning an conducting makes me feel good and save. approach was smooth and well established, we just had 5nm level in which we bustet 40kt speed and 2nm at 210. is that too conservative?? never thought about that in 4 years, but seems so.
what do you think?
greetz from denmark
OD
appreciating your opinion in the following situation:
1. Having a discussion with a collegue about autobrake: He claims, autobrake doenstn make sense, he switches it always off. I claimed that autobrake is a usefull tool. what do you think are the pros and the negative points of using that tool? How do you handle it?
2.Approach, straight in. We had pretty strong tailwind, also the glide intercept on the airport was pretty low, exactly 2000 agl, 7nm out. i preferred to fly not so speedy, leveling of at 13nm to get rid of the 250kt to 210 with the aim in driving the flaps 1 and 10 at 10nm. my collegue meant in the approach, that it was to conservative and we were flying too much level. i just answered, that this approach planning an conducting makes me feel good and save. approach was smooth and well established, we just had 5nm level in which we bustet 40kt speed and 2nm at 210. is that too conservative?? never thought about that in 4 years, but seems so.
what do you think?
greetz from denmark
OD
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i feel that if you want to use the autobrake go ahead. shouldn't be greater than 2 unless needed. with a tail wind depending on field length i would use it as well. although when you have a 12000 ft runway why use autobrake or brakes at all. reverse has more effect at high speeds anyway.
your approach seems fine. i think that the other guy just wants you to see what the plane can do. i like to test my ability at times but only in a safe enviroment. it is anoying when someone is real slow and conservative unless you are over gurantee then the slower the better.
your approach seems fine. i think that the other guy just wants you to see what the plane can do. i like to test my ability at times but only in a safe enviroment. it is anoying when someone is real slow and conservative unless you are over gurantee then the slower the better.
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1, use autobrake, every single time
2 Your figures sound good. Try and manage your energy so you don't have to use much power during the approach. Level decelerations make it easier to manage, but for noise reasons, they are getting unpopular. Many airports now specify CDAs, so you must manage descent and deceleration at the same time to keep the figures looking good- not so easy.
Always remember to allow for HWC in your slowdown calculations- it makes a big difference.
2 Your figures sound good. Try and manage your energy so you don't have to use much power during the approach. Level decelerations make it easier to manage, but for noise reasons, they are getting unpopular. Many airports now specify CDAs, so you must manage descent and deceleration at the same time to keep the figures looking good- not so easy.
Always remember to allow for HWC in your slowdown calculations- it makes a big difference.
I always use Auto Brakes, the only thing that varies is when I disconnect. I have not flown a 737 for 20 years and fly the 744, but an interesting exercise in the Sim is to reject at V1 using manual brakes and then use AB in RTO. On the 744 manual brakes uses 200 -300 meters more regardless of how hard you stomp them. To be fair, I think you were thinking about the choice for landing only?
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You are flying......
OD,
You are flying, not your colleague, fly the jet in a way it is comfortable for you. You have done an excellent job planning your descent, speed reduction and configuration changes to manage your energy. There is more than “one” way to accomplish a safe approach.
Years ago I came to the conclusion that when somebody makes a statement with the words never or always; for example: “He claims, autobrake doesn’t make sense, he switches it always off”, the statement is usually false.
The autobrake system is part of the certification of the jet. As somebody else mentioned it does an excellent job stopping the jet on an aborted takeoff. Some of the non-normal/emergency stopping distances are calculated using the autobrake system and according to our emergency checklist their use is mandatory. Last winter I had a jammed flap and had to divert to an alternate airport for landing. In that case we used max autobrakes, according to the checklist, to get the jet stopped. They worked great and were not violent in any way just extremely efficient braking.
Keep up the good work!
Respectfully,
You are flying, not your colleague, fly the jet in a way it is comfortable for you. You have done an excellent job planning your descent, speed reduction and configuration changes to manage your energy. There is more than “one” way to accomplish a safe approach.
Years ago I came to the conclusion that when somebody makes a statement with the words never or always; for example: “He claims, autobrake doesn’t make sense, he switches it always off”, the statement is usually false.
The autobrake system is part of the certification of the jet. As somebody else mentioned it does an excellent job stopping the jet on an aborted takeoff. Some of the non-normal/emergency stopping distances are calculated using the autobrake system and according to our emergency checklist their use is mandatory. Last winter I had a jammed flap and had to divert to an alternate airport for landing. In that case we used max autobrakes, according to the checklist, to get the jet stopped. They worked great and were not violent in any way just extremely efficient braking.
Keep up the good work!
Respectfully,
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Autobrake should be selected always to enable the aircraft to stop on the available runway. In wet or slippery conditions setting '2' is the minimum as per Mr. Boeing.
Get the speed under control in a comfortable way, much easier with autobrake and less worrying for the punters if the heavy foot of the captain needs correcting inputs.
A steady and smooth deceleration reduces also the uneven wear and tear, beside all this, several checks with heat-sensing cameras provided by the fire service at my home base showed a much lower heat being generated compared to manual braking.
Just my 2 Dirhams .......
Get the speed under control in a comfortable way, much easier with autobrake and less worrying for the punters if the heavy foot of the captain needs correcting inputs.
A steady and smooth deceleration reduces also the uneven wear and tear, beside all this, several checks with heat-sensing cameras provided by the fire service at my home base showed a much lower heat being generated compared to manual braking.
Just my 2 Dirhams .......
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For the 737 the use of autobrake for landing is not necessary unless the runway is limited. You have to read the Boeing FCTM wording carefully. Mine states "Boeing recommends that whenever runway limited, using higher than normal approach speeds, landing on slippery runways or landing in a crosswind the autobrake sysytem be used". The FCTM then expands that by stating when to use max, Med or min (or their equivalent numbers such as 1,2,3 or Max. By "landing in a crosswind" the intent is that it assumes a strong crosswind - not just a few knots.
Obviously if there is no problem with runway length and runway is dry there is nothing to gain by using autobrake except to increase maintenance costs by the fact that the brakes are applied at high speed immediately on wheel spin-up. Providing you you fly the aircraft at the correct speed and touch down at the correct point with little or no float, then the combined retardation effect of spoilers and immediate reverse thrust will easily reduce the aircraft energy such that you would not touch the brakes until the speed is down to 80 knots or less.
On the other hand if you are used to sloppy flying habits and habitually come in with unwarranted excess speed and touch down long after a lengthy float then use of autobrake will not correct your sloppy flying but will give you a head start in the stopping process. But to routinely select autobrake for all normal landings regardless of excess runway length is just plain lazy flying. If you desire to make a certain taxiway not far up the runway even though there is excess runway available over the flight manual factored figure, then go ahead and fill your boots with the autobrake. The way some pilots love the autobrakes for all landings regardless of excess length available makes one wonder if they would send out a Pan call if they had to use manual brakes one day.
If however there is a airport requirement not to use reverse (or only idle reverse)because of noise abatement reasons then the use of an appropriate autobrake setting may be worth considering.
Obviously if there is no problem with runway length and runway is dry there is nothing to gain by using autobrake except to increase maintenance costs by the fact that the brakes are applied at high speed immediately on wheel spin-up. Providing you you fly the aircraft at the correct speed and touch down at the correct point with little or no float, then the combined retardation effect of spoilers and immediate reverse thrust will easily reduce the aircraft energy such that you would not touch the brakes until the speed is down to 80 knots or less.
On the other hand if you are used to sloppy flying habits and habitually come in with unwarranted excess speed and touch down long after a lengthy float then use of autobrake will not correct your sloppy flying but will give you a head start in the stopping process. But to routinely select autobrake for all normal landings regardless of excess runway length is just plain lazy flying. If you desire to make a certain taxiway not far up the runway even though there is excess runway available over the flight manual factored figure, then go ahead and fill your boots with the autobrake. The way some pilots love the autobrakes for all landings regardless of excess length available makes one wonder if they would send out a Pan call if they had to use manual brakes one day.
If however there is a airport requirement not to use reverse (or only idle reverse)because of noise abatement reasons then the use of an appropriate autobrake setting may be worth considering.
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All these questions, OD - do you have any SOPs in whichever company you fly for?
If so, 'refer' your 'questioning' colleagues to those.
If not, my preference would be: Autobrake as necessary eg if you are vacating at the end of a 10,000ft runway, none. Assuming you do fly a 737, you should have access to a QRP and if you wish/need/have to use autobrake, you should use the autobrake landing roll figures in that for the intended exit point. It can always be cancelled once things are 'under control' or change.
- I don't understand that.
Now, depending on which ?seat you are in?
a) If left, take control if you don't 'like' the way the F/O is flying.
b) If right, say 'You have control'.
Then discuss it on the ground - NOT in the air.
Simple, no?
If so, 'refer' your 'questioning' colleagues to those.If not, my preference would be: Autobrake as necessary eg if you are vacating at the end of a 10,000ft runway, none. Assuming you do fly a 737, you should have access to a QRP and if you wish/need/have to use autobrake, you should use the autobrake landing roll figures in that for the intended exit point. It can always be cancelled once things are 'under control' or change.
5nm level in which we bustet 40kt speed and 2nm at 210.
Now, depending on which ?seat you are in?
a) If left, take control if you don't 'like' the way the F/O is flying.
b) If right, say 'You have control'.
Then discuss it on the ground - NOT in the air.
Simple, no?
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I flew 737400 for 4 years, Airbus A306 now. Sure enough you have seen what is written on the Boeing FCTM abou autobrake, no choice but to agree with that - rite?
However, I personally believe that no matter how perfect the condition is, Autobrake still doing me favor by providing that initial deceleration upon touchdown while we are busy flying the nose wheel down to the runway. That doesent seem alot of distance, but actually it is.
Respectfully,
However, I personally believe that no matter how perfect the condition is, Autobrake still doing me favor by providing that initial deceleration upon touchdown while we are busy flying the nose wheel down to the runway. That doesent seem alot of distance, but actually it is.
Respectfully,
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Haven't got the 737-8 FCTM in front of me but pretty sure it reckons Auto 1 should be adequate for most ops, don't think it goes further but assumes at least some, maybe even most, of the pilots may have some logic and brain functions! 
Was never a fan of autobrake on the classic but gotta admit on the -800 auto 2 and reverse on touchdown does a very nice job when I want to make a highspeed for whatever reason.
Getting rid of the autobrake (smoothly) still a work in progress.
Cheers
galdian
Was never a fan of autobrake on the classic but gotta admit on the -800 auto 2 and reverse on touchdown does a very nice job when I want to make a highspeed for whatever reason.
Getting rid of the autobrake (smoothly) still a work in progress.
Cheers
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a) If left, take control if you don't 'like' the way the F/O is flying.
b) If right, say 'You have control'.
b) If right, say 'You have control'.
I find option b) works very well with "I know best when to use flaps 5" types :-)
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Well I'm fascinated! What weird convoluted logic do some of you have that causes a reluctance to use autobrake on the 737? Read your company manual! It should say something like the most economical landing is autobrake and idle reverse. That use of autobrake allows several seconds earlier braking! Some of you criticise 'use autobrake every time' without actually saying why not and why you think it is better not to use a system that guarantees even and smooth braking. I've been a bigjet pilot for 38 years- I still can't do a balanced manual brake landing. Captains press too hard on the left and copilots press too hard on the right. I'm interested in ONE logical reason not to use it! I agree with the current logic that reverse is better and more economical limited to idle only. Brake units are simple to change, big fan reverse mechanisms are expensive to repair, so idle only. It helps to have something to stop you!
This place is too big, with a cacophany of voices. If someone says it's black, several will pipe up with 'it's really white, actually!' I cannot understand it.
This place is too big, with a cacophany of voices. If someone says it's black, several will pipe up with 'it's really white, actually!' I cannot understand it.
I've been a bigjet pilot for 38 years- I still can't do a balanced manual brake landing
Last edited by Centaurus; 14th Dec 2008 at 03:25.
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You certainly appear to have a problem.
As a non-pilot, I got the impression that landing was primarily a "heads-up" task. Do your trainers want pilots to spend more time with their heads down? (or is this compass thing a sim exercise?).
And how do you differentiate between heavy toe(brakes) and heavy heel(rudder)? Surely both affect compass heading. One could be fighting the other and you could still end up with brakes cooked on one side.
Rgds.
NSEU
Our company mandates autobrake use for every landing. Seems like overkill when we are cleared to roll through to the end of a 4000 metre runway, but as the saying goes "It's their trainset."
In the above example there is nothing to say you can't apply some manual braking and cause the autobrakes to disarm soon after touchdown though.
For all other situations I use a table I've created from a graph found in the performance limitations manual, stating the expected ground roll given an autobrakes setting and ground speed on touchdown. You can estimate your groundspeed using TAS and HW/TW component.
The figures seem to work for both the B737-400 and B737-800
So for Autobrakes 1, 2, 3, MAX. the landing roll (from touch-down) in metres is:
120 kt = 1550, 1200, 950, 550.
125 kt = 1650, 1350, 1050, 650.
130 kt = 1800, 1500, 1150, 700.
135 kt = 1950, 1550, 1200, 700.
140 kt = 2100, 1650, 1300, 750.
145 kt = 2250, 1800, 1350, 850.
150 kt = 2400, 1900, 1500, 900.
155 kt = 2550, 2000, 1550, 950.
160 kt = 2700, 2150, 1650, 1050.
165 kt = 2800, 2300, 1700, 1050.
170 kt = 3000, 2400, 1800, 1100.
I add another 400 metres to the above figures to allow for the 300 metres aiming point on the runway and 100 metres for the flare.
If I want to turn off at a certain taxiway, I just look to see on the airport diagram how far it is down the runway, then using my approach speed, airport elevation and temperature, calculate a TAS, apply a headwind or tailwind component from the reported wind, and select an appropriate autobrake setting.
It works beautifully. If I do float a bit more than usual I know just how much extra manual braking I will need to turn off at the desired taxiway, or if I don't think I will make it, I can simply apply manual brakes to disarm the autobrakes and allow it to roll through to the next one. There is nothing worse than trying hard to make a taxiway and only just missing it and then having to roll through to the next one at low speed. If you had have done the calculations above, you would have known in advance that you were never going to make the chosen turn-off and you would have simply kept the speed up and turned off at the next one.
Either way, it minimises the time you occupy the runway.
It also helps for non-normal situation such as engine out landing or flaps non-normal. Again if you have to land with Flaps 15 and associated higher approach speed, you can calculate your ground speed on final approach, and see what autobrake setting is going to have you pulling up with an adequate margin for the given runway length, without blowing the tyre fuse plugs because you unnecessarily overcooked the brakes.
Works for me anyway.
P.S. I just noticed something. As you know kinetic energy is proportional to speed squared.
The distances listed above for 170 kt are twice those of 120 kt.
170^2 = 2890.
120^2 = 1440.
2890/1440 = 2.00.
Therefore I think this validates the data given above.
In the above example there is nothing to say you can't apply some manual braking and cause the autobrakes to disarm soon after touchdown though.
For all other situations I use a table I've created from a graph found in the performance limitations manual, stating the expected ground roll given an autobrakes setting and ground speed on touchdown. You can estimate your groundspeed using TAS and HW/TW component.
The figures seem to work for both the B737-400 and B737-800
So for Autobrakes 1, 2, 3, MAX. the landing roll (from touch-down) in metres is:
120 kt = 1550, 1200, 950, 550.
125 kt = 1650, 1350, 1050, 650.
130 kt = 1800, 1500, 1150, 700.
135 kt = 1950, 1550, 1200, 700.
140 kt = 2100, 1650, 1300, 750.
145 kt = 2250, 1800, 1350, 850.
150 kt = 2400, 1900, 1500, 900.
155 kt = 2550, 2000, 1550, 950.
160 kt = 2700, 2150, 1650, 1050.
165 kt = 2800, 2300, 1700, 1050.
170 kt = 3000, 2400, 1800, 1100.
I add another 400 metres to the above figures to allow for the 300 metres aiming point on the runway and 100 metres for the flare.
If I want to turn off at a certain taxiway, I just look to see on the airport diagram how far it is down the runway, then using my approach speed, airport elevation and temperature, calculate a TAS, apply a headwind or tailwind component from the reported wind, and select an appropriate autobrake setting.
It works beautifully. If I do float a bit more than usual I know just how much extra manual braking I will need to turn off at the desired taxiway, or if I don't think I will make it, I can simply apply manual brakes to disarm the autobrakes and allow it to roll through to the next one. There is nothing worse than trying hard to make a taxiway and only just missing it and then having to roll through to the next one at low speed. If you had have done the calculations above, you would have known in advance that you were never going to make the chosen turn-off and you would have simply kept the speed up and turned off at the next one.
Either way, it minimises the time you occupy the runway.
It also helps for non-normal situation such as engine out landing or flaps non-normal. Again if you have to land with Flaps 15 and associated higher approach speed, you can calculate your ground speed on final approach, and see what autobrake setting is going to have you pulling up with an adequate margin for the given runway length, without blowing the tyre fuse plugs because you unnecessarily overcooked the brakes.
Works for me anyway.
P.S. I just noticed something. As you know kinetic energy is proportional to speed squared.
The distances listed above for 170 kt are twice those of 120 kt.
170^2 = 2890.
120^2 = 1440.
2890/1440 = 2.00.
Therefore I think this validates the data given above.
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I use a table I've created from a graph found in the performance limitations manual,
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I'm with Rainboe. Autobrakes are a godsend - especially with a stiff crosswind where maintaining equal/sufficient brake pressure whilst pedalling the rudders is extremely difficult. Nobody is saying they are unable to brake manually. When some of you transition to large metal that require more thought when stopping you will appreciate the response the Rainboe gives. A 737 would come to a halt in 3000m doing nothing
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In reviewing the Boeing Brake Cooling Chart as contained in the approved Boeing Performancing and Planning Manual (both chart and text description), use of auto brakes will produce more favorable brake cooling than use of manual braking.
Use of thrust reverse will produce less brake energy, thus lower brake temperatures. Why complicate things? keep it simple use them if they are operational.
Just a question... is there anyone that monitors their compass during landing roll to for directional control during landing? The PF controls the jet, while the NPF monitors speed and engine trends during decelaration.
I would love to see an actual FCOM that makes that statement "monitor compass for heading deviation during braking during landing roll", if it really exists.
Use of thrust reverse will produce less brake energy, thus lower brake temperatures. Why complicate things? keep it simple use them if they are operational.
Just a question... is there anyone that monitors their compass during landing roll to for directional control during landing? The PF controls the jet, while the NPF monitors speed and engine trends during decelaration.
I would love to see an actual FCOM that makes that statement "monitor compass for heading deviation during braking during landing roll", if it really exists.