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-   -   How to decide landing config? (https://www.pprune.org/tech-log/517052-how-decide-landing-config.html)

Jack1985 14th Jun 2013 22:09

How to decide landing config?
 
How do pilots decide upon a landing config especially on Airbus aircraft how do you come to the conclusion of using CONF 3 or CONF 4? And with regards selecting auto brake? Also how do you judge reverse thrust i.e reverse 1 or 2 and maybe no reverse just brakes?

Thanks!

Dash8driver1312 14th Jun 2013 23:40

How to decide landing config?
 
This little thing called Standard Operating Procedures to start with, combined with landing distance calculations, continuation training, and experience!

For example, sometimes we take full flaps to shorten a landing roll to take a more convenient exit, or simply reduce the ground speed to reduce wear on the brakes, etc

Love_joy 14th Jun 2013 23:46

SOP's is a good answer, it's essentially whatever the company want you to use.

But in essence, it's all about what's more relevant. Some pilots have a preference for one setting over another, but it still has to be appropriate and you have to have performance to actually complete it.

nitpicker330 14th Jun 2013 23:47

Agree with Dash......

SOP's

A330 normal procedure is Config Full AND full Reverse.
Windshear/Gusty turbulent conditions expected? its optional to use a Config 3.

Long dry runway? Idle Reverse is acceptable.

Don't be a test Pilot, follow Airbus and your companies SOP's :ok:

Silvio Pettirossi 15th Jun 2013 00:03

At my company, all landings should be conf3. With the exception off landings on wet or contaminated runways or short runways (1800m or less), in this cases we use conf full.
About autobrake, well again, on wet, short or contaminated runways, autobrake MED should be used. In other cases you can also use the Low setting, depending on the location of the taxiway you would prefer to use to vacate. In any case, the use of autobrake is recomendet.
We use idle reverse only on both sides on long and dry runways if everything is working normaly. No reverse at all is not recomendet.
Conf3 approaches burn less fuel and idle reverse on landing reduces engine maintenaince costs as well as fuel costs. We fly airbus narrowbodys.

DownIn3Green 15th Jun 2013 01:29

Landing Configuration?

Well, let's see....

1. Gear Down...

2....Flaps Down...

3....Speed..as per flaps selected....

4....Thrust levers idle..once MLG spin-up...

So follow that and you'll be OK....

Willit Run 15th Jun 2013 04:33

3 Green, you beat me to it!

this job just isn't that complicated.

Mashuk 15th Jun 2013 06:37

Upon receiving weather before descent/approach breifing check aircraft performance.
Determine approach speed depending landing weight with full/not full landing flaps.
You have expected taxiway/s to vacate the runway. Determine landing roll distance using full landing distance (from ILS glidepath touchdown) and distance/s to expected taxiway/s. You will get distance/is anyway.
Next you can choose autobrake level and reverse thrust level (full/idle).
Upon touchdown you may check if any rorrection required. If you touchdown away from touchdown zone use highr level of outbrakes or use manual brakes higher level to vacate RW via expected taxiway or use same decceliration level to vacate via next taxiway using same deceliration level.

Just one thing - lower approach speed is lower deceliration level required is less tire and brake wearing.
But good performance knowlege is key for good practice.
Also before take-off breifing check performance for overweight landing at departure airfield/ RWy with existing RWy condition. You will get aircraft ability to land with overweight landing.
Just think about performance...

Mashuk 15th Jun 2013 06:39

Also do not forget about tail clearance on touchdown.
More clearance is better but not always.

de facto 15th Jun 2013 10:53


More clearance is better but not always.
Which one is it then?:8

you touchdown away from touchdown zone use highr level of outbrakes or use manual brakes higher level to vacate RW via expected taxiway
So you plan one thing and if it doesnt work you increase the braking?maybe knowing in advance if increased AB would be enough is a good idea..

The whole point is to know where is your average touch down point and this is added to your calculated distance with AB setting,if you are runway limited then an overshoot of your touchdown will end up in a balked landing...

Cough 15th Jun 2013 13:26


4....Thrust levers idle..once MLG spin-up...
And


So follow that and you'll be OK....
Gulp. Really sorry, but I'm not going to follow your advice next time I land on a wet runway at GIB. Nothing personal...

BOAC 16th Jun 2013 08:01

What he said?

de facto 16th Jun 2013 09:06


What he said?
Thought you knew...:p,my head still spinning.


Naturally, you will have worked out the flap setting to be used prior to the approach, during the approach briefing, you will also have mentioned that if Flaps 3 does not work then we`ll use flaps Full or the other way around - not quite using those words . . but you get my drift?
Nope.

Jack1985 16th Jun 2013 18:13

Thanks for the comments guys lots of varying answers, a final question if some of you could answer when would you start configuring the flaps for landing i.e. commencing the final descent? I've been talking to a few local pilots at Cork and 15 nm to 20 nm seems to be the norm? I'm particularly interested in when you start to lower the flaps and do you need to lower them earlier if you're going to be landing with CONF 4 rather than CONF 3.

de facto 17th Jun 2013 03:59

You start to configure when either ATC tell you to or depending on your altitude/distance for the airport.
The optimum is to delay the flaps until :
ATC forcing you to(ie 90 base turn and delaying your intercept).
You are sure to achieve a continuous descent until glide intercept,a B737 just like an Airbus 320 I am sure will have idle thrust on the glide at speed 180(no wind).
So if you are on a 3 deg path to the glide configure from up speed to 180 kts starting about 2 miles from glide intercept.

If you happened to be level:} before glide intercept when one 1/2 below start to configure from up to 180 kts.

Hope that helps.
PS remember 10 TW will require at least 1 NM more.

Valmont 17th Jun 2013 21:21

Jack,

If you do not have any ATC constraint, on a continuous descent and depending on the wind. I'll usually start reducing speed from 250kts at 18nm from touchdown. 12nm conf 1, 8nm conf 2, Gear Down at 2000fts (between 6 and 7 miles), then then configure for landing in sequence and ldg checklist.

With a tailwind, follow de facto's advice.

captjns 17th Jun 2013 23:51

Configuration. Hmmm. You mean there's a choice between gear up or gear down?:}

Natstrackalpha 11th Jul 2013 23:18


You start to configure when either ATC tell you to
Yeh, right. Who told you that?

We will have worked out our approach (strategy) in the approach briefing - one of us gives the briefing but its a 2 way thing.

We look at the approach and the met and w/v and the condition of the aircraft and weight alt temp considerations runway length any considerations of the runway and surrounding terrain, traffic, everything - under alt will come MSA - we will also look at how we are going to do a go around should that be necessary for any reason - like a herd of elephants crossing the runway just as we are about to land, that sort of thing.

Depending on traffic, time of day, atc >> traffic, time of day, we expect, ideally to do a seamless approach to intercept the glideslope (guidance in elevation) and the localiser (guidance in azimuth [right or left]) or Instrument Landing System or other type of precision or non precision approach or visual approach.

We know and get used to our aircraft but, we have charts which will help us to make a decision as to what speed we will be at by a certain distance from touchdown.

For example if we are constrained to be at a low speed earlier on in the approach then we would configure earlier, depending on that speed.

Approaching over sea coasting in to an airport over featureless terrain and no obstacles which is also flat near sea level with few if any population and with no traffic around we might descend from cruise straight to 2,000 having planned this way back up there at cruise altitude, to be level by 2,000 feet say, then cleared down to say 1700 feet with no speed restriction and using slight reduction in rate of descent to decrease speed and as we pass a certain low speed say 180kts for example then we would prepare for lowering one stage of flap. Leaving 180 decellerating would call for flap 1. Decellerating further flap 2 aiming to have flap 3 by 160kts. At about one dot below the glideslope meaning just before we are fully established on the glideslope and descending with it, we would select gear down - another way of looking at this is, instead, distance from touchdown, so you could say at 4.5 miles select gear down and full flap - for example - So overall it is usually based on distance (from touchdown) and altitude but moreover - speed as to when you configure.

If we configure too early, after having got the speed back then we end up dragging the aircraft in on a slow approach with high power settings and loads of noise, if there were traffic behind us then we would be holding everybody up and the queue would not be appreciated by pilots, controllers and passengers alike, who would be awful :mad: off at losing their connecting flights . . . also we would use more fuel that way.

If we configure too late then we run the risk of not being "stabilised" by a certain altitude, at some airlines this is 1,000 feet - at others it may be different - in this case we would have to go around.

So all in all we configure by a certain dist from touchdown, a certain altitude and, a certain speed - we decide when to configure - not ATC.

Re: your last question - we decide on whether to land with Flaps3 or 4 by consulting the flip card which will have the weight of the aircraft, outside temp, we select the appropriate card where the figures all match up and it will give us its recommendation. Should we decide that Flaps 3 is not enough for any reason and that, indeed, Flaps full is more appropriate then we would select Flaps full.


Also how do you judge reverse thrust i.e reverse 1 or 2 and maybe no reverse just brakes?
We would not have Reverse 1 or 2, if we could help it - the only time this would happen is if reverse 1, or 2, was inop, or if landing single engine but we try to avoid asymetric reversers if possible, you can imagine why.

We would use brakes with no reverse if, we were light and did not have to land and hold short or take an early turnoff or we had to / could roll right to the end of a long runway, in other words if we did not have to slow quickly or use brakes too much . . . there is little point in foregoing reverse but end up burning your brakes . . .under certain conditions we cannot use reverse.

We can land with autobrake minimum or medium, again it depends on condition of aircraft, heat of brakes, weight, temperature and length and condition of runway available.

aviatorhi 12th Jul 2013 05:30

245@1500 to 7nm then drop flaps and gear accordingly... Flaps 30 max-10 to 3 DME. Spool up at 500 and Land.

I always land flaps 30 (Boeing) unless 40 is necessary.


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