Airbus - Flap FULL or Flap 3??
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Well, look Dozza...
go see your Flight Manager, tell him you want his job, and if you get it, then rewrite the Ops Manual to suit yourself. But, and it's a big but, make sure you know what you're talking about.
you get my drift?
go see your Flight Manager, tell him you want his job, and if you get it, then rewrite the Ops Manual to suit yourself. But, and it's a big but, make sure you know what you're talking about.
you get my drift?
Come on amos2, it was a clear and relevant question from Dozza2k. My reply was probably more flippant ...... Yours? Well, you've shown your true colours - had a bad day at the office?
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I know this topic is a bit old, but I just had to mention my company's policy. After fuel going up in the last few years they have sent a notice to flight crew asking us to try and land when ever possible CONF3 as it reduces fuel burn on the approach. We have never had a tail strike in the last 6 years operating 320/321. I can understand their philosophy, but I don't think we should over use CONF3 except for the odd time to keep current with power setting, pitch attitude and flare technique.
The only thing that has worried me in the last 2 weeks is that I heard from a line training captain that they might impose CONF3 to become the normal operation in the OPS manual, which I believe is not right. CONF3 and FULL should be a crews decision to make and not be made into a standard operating technique.
I hope you enjoyed my contribution.
The only thing that has worried me in the last 2 weeks is that I heard from a line training captain that they might impose CONF3 to become the normal operation in the OPS manual, which I believe is not right. CONF3 and FULL should be a crews decision to make and not be made into a standard operating technique.
I hope you enjoyed my contribution.
Ramasseur des pommes
Our company believes that use of Config 3 saves 20kg of fuel and it is the SOP landing configuration. It turns out that this fuel saving is only happens if you are fully configured for landing at 13 miles. Most of the final approaches on our route network don't come anywhere close to a 13 mile final (notwithstanding the rare and weird 30nm final
). It seems to me an accountant's fudge; as any fule no, how the approach is flown from top of drop makes more difference than any flap configuration. 
As mcdhu says, thrust is not one of our stable criteria; it used to be, but the Autothrust seems to almost hunt for the correct power setting in Config 3, which is probably why the requirement for thrust was removed – it's just not necessarily there at 500'!
). It seems to me an accountant's fudge; as any fule no, how the approach is flown from top of drop makes more difference than any flap configuration. As mcdhu says, thrust is not one of our stable criteria; it used to be, but the Autothrust seems to almost hunt for the correct power setting in Config 3, which is probably why the requirement for thrust was removed – it's just not necessarily there at 500'!
Applemacmaster:
We work for the same Company I belive and I can assure your information regarding fuel savings isn't correct. The actual fuel savings will vary due to weight and pilot technique. In fact there is actually no single figure for the A320 family. The values vary with the speed, which varies with each engine/aircraft/weight combination plus the engine characteristics (TI vs. non-TI) etc. You can be assured, however, that the average montly saving due to CONF 3 comes close to 10 times the TRIP fuel requirements from SSH to LGW - small numbers add up when you fly 1,100 flights/day.
On the Airbus there has never been a requirement to have a minimum thrust setting on the approach, the aircraft certification standards (FAR – Part 25) ensure that the thrust achieved after 8 seconds from power application (starting from flight/approach idle) allows a minimum climb gradient of 3.2 % for go-around.
The issue of tailstrikes on the A321 decreases when using CONF 3 instead of CONF FULL. This behavior can be explained when looking carefully at the lift surfaces. The A321 has doubleslotted fowler flaps, instead of single slotted flaps on the A319 and A320. Most tailstrikes occur due to aircraft mishandling.
Have a good summer.
We work for the same Company I belive and I can assure your information regarding fuel savings isn't correct. The actual fuel savings will vary due to weight and pilot technique. In fact there is actually no single figure for the A320 family. The values vary with the speed, which varies with each engine/aircraft/weight combination plus the engine characteristics (TI vs. non-TI) etc. You can be assured, however, that the average montly saving due to CONF 3 comes close to 10 times the TRIP fuel requirements from SSH to LGW - small numbers add up when you fly 1,100 flights/day.
On the Airbus there has never been a requirement to have a minimum thrust setting on the approach, the aircraft certification standards (FAR – Part 25) ensure that the thrust achieved after 8 seconds from power application (starting from flight/approach idle) allows a minimum climb gradient of 3.2 % for go-around.
The issue of tailstrikes on the A321 decreases when using CONF 3 instead of CONF FULL. This behavior can be explained when looking carefully at the lift surfaces. The A321 has doubleslotted fowler flaps, instead of single slotted flaps on the A319 and A320. Most tailstrikes occur due to aircraft mishandling.
Have a good summer.
landing withe confg 3
Ramasseur des pommes
Lyka,
Thanks for the detail; I'm happy to accept that I may have been misinformed (although my source was pretty good), but there is a dearth of (detailed) information on the subject. However, a lot of people still need a lot of convincing. I don't mind doing Config 3 landings, and quite like doing them for the team (200+ landings a year * "20kg" is a lot of fuel); in fact, I'm nerdy enough to log whether it's Config 3 or Full in my logbook. I still feel that there isn't enough focus on saving fuel in the rest of the sector; it's almost as if the emphasis is wholly on the landing Config, whereas a larger saving is to be made elsewhere. For example, I'm quite pro-active in trying to get shortcuts, but some guys will just stick with the flightplan.
Very interesting about the 321. I don't fly it, but a lot of guys who used to fly it would swear blind that it's a bad idea. Again, education is key.
Thanks for the detail; I'm happy to accept that I may have been misinformed (although my source was pretty good), but there is a dearth of (detailed) information on the subject. However, a lot of people still need a lot of convincing. I don't mind doing Config 3 landings, and quite like doing them for the team (200+ landings a year * "20kg" is a lot of fuel); in fact, I'm nerdy enough to log whether it's Config 3 or Full in my logbook. I still feel that there isn't enough focus on saving fuel in the rest of the sector; it's almost as if the emphasis is wholly on the landing Config, whereas a larger saving is to be made elsewhere. For example, I'm quite pro-active in trying to get shortcuts, but some guys will just stick with the flightplan.
Very interesting about the 321. I don't fly it, but a lot of guys who used to fly it would swear blind that it's a bad idea. Again, education is key.
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Most heavy a/c i have flown are easier to land with full flaps as you will establish approach speed easier - close to MALW you need every drag you can get. Another point is the line of sight, but I guess all those who need not see the TDZ are well of with lower flap settings.
On the other hand, instead of dumping 20000 gallons, consider an overweight landing, and you will need lower flaps (3/25/30/etc.) and a long rwy.
On the other hand, instead of dumping 20000 gallons, consider an overweight landing, and you will need lower flaps (3/25/30/etc.) and a long rwy.
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I am glad that this topic has been resurrected. There is an ongoing debate by the line pilots at my carrier (at least out west here in PHX) about the purported saving in Config 3 landings. The company is saying that Config 3 is now the standard flap setting and full is to be only used when necessary for performance (wet, contaminated, Cat 3, etc.)
We have heard the same 20 kgs (50 lbs for us in the USA) savings mentioned but then someone brought up the point that all this is negated if you use greater than Idle reverse on landing.
In the Airbus (particularly the 321) you have far less stopping area on the disks (2 wheels per main gear) vs the larger Boeings. 737 and 319/320 are the same, of course. But pound for pound the Airbus empty weights are greater than the Boeing 737s. So you are using reverse thrust to compensate for the lesser stopping power of the Airbus brakes. The carbon brakes work best when heated but if you use Autobrake (recommended) then you have a 4 second delay before the brakes kick in. And you are coming in with cold brakes unless you are doing 45 minute sectors. Meanwhile the reversers are engaged and because we all want to stop before the end (always my main goal) we slide the revesers back to full. Look at the fuel flow - you will see about 1800 lbs/hr fuel flow per side while in reverse. Bring them to idle at 80 or 60 kts and you will have used your 50 lbs and maybe more. If you don't single engine taxi after your 3 minute cool down then you will burn 50 more. And don't forget, if you dropped the gear and went to final flaps at the FAF then you burned hundreds more pounds or kgs of fuel.
VFR I will drop the gear at 1500' agl and go to final flaps (3 or full) at 1000'. I will go managed speed at 5 miles out. I am spooled and stable between 1000' to 500' which is our VFR gate. Thats about as close to a constant idle descent as I can get and still be wiithin company parameters. Few F/Os I fly with will do that so I know that we are wasting far more fuel with early configurations and prolonged use of reverse than landing Config 3.
We have heard the same 20 kgs (50 lbs for us in the USA) savings mentioned but then someone brought up the point that all this is negated if you use greater than Idle reverse on landing.
In the Airbus (particularly the 321) you have far less stopping area on the disks (2 wheels per main gear) vs the larger Boeings. 737 and 319/320 are the same, of course. But pound for pound the Airbus empty weights are greater than the Boeing 737s. So you are using reverse thrust to compensate for the lesser stopping power of the Airbus brakes. The carbon brakes work best when heated but if you use Autobrake (recommended) then you have a 4 second delay before the brakes kick in. And you are coming in with cold brakes unless you are doing 45 minute sectors. Meanwhile the reversers are engaged and because we all want to stop before the end (always my main goal) we slide the revesers back to full. Look at the fuel flow - you will see about 1800 lbs/hr fuel flow per side while in reverse. Bring them to idle at 80 or 60 kts and you will have used your 50 lbs and maybe more. If you don't single engine taxi after your 3 minute cool down then you will burn 50 more. And don't forget, if you dropped the gear and went to final flaps at the FAF then you burned hundreds more pounds or kgs of fuel.
VFR I will drop the gear at 1500' agl and go to final flaps (3 or full) at 1000'. I will go managed speed at 5 miles out. I am spooled and stable between 1000' to 500' which is our VFR gate. Thats about as close to a constant idle descent as I can get and still be wiithin company parameters. Few F/Os I fly with will do that so I know that we are wasting far more fuel with early configurations and prolonged use of reverse than landing Config 3.
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I assume we are talking A320 family here 
As above, my Big employer has an "SOP" for F3 on 320/321, FF on 319, in order to "save fuel". However, either Flap setting can be used on any model as crew see fit, and they also give a long list of factors that might affect that decision (e.g. EAI, tailwind, LDA).
My observations:[LIST=1][*]F3 saves about 7Kgs an approach - assuming the F3 to FF is selected just prior 1000' for "stabilised approach criteria"
[*]A321 and A319 F3/FF Vapp is ~10K different, and attitude little changed[*]A320 only adds about 3K, and has much higher nose attitude, confirmed by "high nose attitude on Landing events" being a problem on, almost exclusively, F3 A320 approaches[*]On the A321 this can result in a comparatively high approach speed, which some circumstances might dictate best avoided[*]On the A319 the extra 10K can be very useful to get a decent approach speed / make an exit[*]My RHS colleagues do have a good line in excuses not to use F3 - which I can only assume reflects what most LHS do...
As above, my Big employer has an "SOP" for F3 on 320/321, FF on 319, in order to "save fuel". However, either Flap setting can be used on any model as crew see fit, and they also give a long list of factors that might affect that decision (e.g. EAI, tailwind, LDA).
My observations:[LIST=1][*]F3 saves about 7Kgs an approach - assuming the F3 to FF is selected just prior 1000' for "stabilised approach criteria"
[*]A321 and A319 F3/FF Vapp is ~10K different, and attitude little changed[*]A320 only adds about 3K, and has much higher nose attitude, confirmed by "high nose attitude on Landing events" being a problem on, almost exclusively, F3 A320 approaches[*]On the A321 this can result in a comparatively high approach speed, which some circumstances might dictate best avoided[*]On the A319 the extra 10K can be very useful to get a decent approach speed / make an exit[*]My RHS colleagues do have a good line in excuses not to use F3 - which I can only assume reflects what most LHS do...
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Lots of good points made here and I just want to add perhaps another way of looking at it.....
If you take all these "fuel saving" measurements/procedures and add them up they will eventually, compared to not applying them, save the company some fuel. Agree on that? I think this is the way to look at it. Coming up with statements like "Yes, saves fuel but if you do not do x, y and z then bla bla or if you do this or that then....etc etc" is not really relevant to wether or not it makes sense to introduce the procedures. Remember, if you need to fly a fully configured approach, or just screw up you descend planning, the benefit of flying config 3 approaches is not lost. You have to compare used fuel on the particular approach compared to what would have been used if flying config full. Yes, more focus should be put on training pilots, and controllers, to fly A-CDAs (or similar) whenever possible. As for single engine taxi I often hear from people that yea but if you taxi uphill to the gate area then you have lost the benefit by using higher thrust setting on running engine". I am no tech geek and I am not sure if the statement is correct, but, if you think this is the case - Don't shut down the engine!! But shut down the engine in all the other 95% of you arrivals and you will, over time, save money.... How hard can it be?
I am all for config 3 landings, single engine taxi in, proper approach and descend planning etc. Saves fuel (money) and the environment.
If you take all these "fuel saving" measurements/procedures and add them up they will eventually, compared to not applying them, save the company some fuel. Agree on that? I think this is the way to look at it. Coming up with statements like "Yes, saves fuel but if you do not do x, y and z then bla bla or if you do this or that then....etc etc" is not really relevant to wether or not it makes sense to introduce the procedures. Remember, if you need to fly a fully configured approach, or just screw up you descend planning, the benefit of flying config 3 approaches is not lost. You have to compare used fuel on the particular approach compared to what would have been used if flying config full. Yes, more focus should be put on training pilots, and controllers, to fly A-CDAs (or similar) whenever possible. As for single engine taxi I often hear from people that yea but if you taxi uphill to the gate area then you have lost the benefit by using higher thrust setting on running engine". I am no tech geek and I am not sure if the statement is correct, but, if you think this is the case - Don't shut down the engine!! But shut down the engine in all the other 95% of you arrivals and you will, over time, save money.... How hard can it be?
I am all for config 3 landings, single engine taxi in, proper approach and descend planning etc. Saves fuel (money) and the environment.
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mcdhu
But Speed is - so if the path and speed are perfect but the thrust is at idle, the a/c must be decelerating, and the approach is not stable.......
Thrust is not one of our Airbus stable approach criteria!!
As for single engine taxi I often hear from people that yea but if you taxi uphill to the gate area then you have lost the benefit by using higher thrust setting on running engine". I am no tech geek and I am not sure if the statement is correct, but, if you think this is the case - Don't shut down the engine!! But shut down the engine in all the other 95% of you arrivals and you will, over time, save money.... How hard can it be?
My Company have published a breakeven distance (i.e., cost) to allow us to make an informed decision about additional taxi time vs. CONF 3 - it gives us a number to work from for RWY exit planning etc.
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LYKA - Thanks for the info. My point was more along the line of use your brain when applying / not applying these procedures and stop trying to convince people that it makes no difference, because it does.
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Hi,
Some interesting views expressed above.
There is an Airbus power point presentation called "Landing in CONF 3 – Use of reversers"
Some interesting views expressed above.
There is an Airbus power point presentation called "Landing in CONF 3 – Use of reversers"
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My company is planning to introduce flap 3 landings on the A320/321 as SOP 
So I searched PPRUNE and found this "old" but interesting tread about the subject.
The reason for the new SOP is : 1. FUEL SAVING and 2. noise
My question is :
Have you seen any documentation about saving money if using flap 3 instead of flap full for landing ?
I mean, I can understand that you are saving a very limited amount of fuel if you are using flap 3 instead of flap full, but we are talking about ~2 min. on each approach, and in my company the aircrafts are doing between 2 and 4 landings pr day so we are not talking about a lot of fuel.
And if you have do make ONE GA due to lack of spool up (which is more likely to happen in flap 3 than flap full) then I guess that what have been saved in a whole year, just disappeared !
And what about the increase the brake wear ? What are the costs here ?
And off course the increase risk of a tailstrike on the 321....
Please share your experience/thoughts
So I searched PPRUNE and found this "old" but interesting tread about the subject.
The reason for the new SOP is : 1. FUEL SAVING and 2. noise
My question is :
Have you seen any documentation about saving money if using flap 3 instead of flap full for landing ?
I mean, I can understand that you are saving a very limited amount of fuel if you are using flap 3 instead of flap full, but we are talking about ~2 min. on each approach, and in my company the aircrafts are doing between 2 and 4 landings pr day so we are not talking about a lot of fuel.
And if you have do make ONE GA due to lack of spool up (which is more likely to happen in flap 3 than flap full) then I guess that what have been saved in a whole year, just disappeared !
And what about the increase the brake wear ? What are the costs here ?
And off course the increase risk of a tailstrike on the 321....
Please share your experience/thoughts
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A few notes:
1- What difference does it make setting landing conf 3 instead of full just at the limit altitude (500 or 1000 ft depending non VMC or IMC)? I think it is negligible with respect to any flighttime not at idle during the approach due to a non optimum TOD and descent. Not to mention the much greater saving of a "more thant optimum descent" such as going low on profile, then "ready for base" and fly some 6 to 10 less NM.
2- does the fuel saving outweights the extra fuel, engine wear and brakes wear due to the extra speed? (in the ecuation of kinetic energy, speed goes squared: a 3% extra speed means a 6% extra energy).
3- I rarely fly conf 3, and i don't like it because i am not used and with light weights thrust is almost idle. And i feel a tailstrike is more likely to occur to me, which is scary.
4- Maybe it is better just to delay flap full until shortly before 1,000 ft, instead of the procedural, when flaps 3, select flaps full
5- a lot of bits of fuel saved can make a big saving in a big airline
6- just one incident (tailstrike) can waste years of saving
7- i would like captains to encourage me to fly conf 3 approaches, but they don`t like it. So i dont like it when a conf 3 is recommended for windshear and gusty winds, because aside from the conditions I have to deal with an unusual attitude and thrust.
8- Extra time taxiing is also a factor, which will occur in many airfields if you use more rwy length. For instance at FCO after landing you may just let it roll with reverse idle to the end. conf 3 that day is fine. But in other airports, the extra speed will be paid either by extra reverse and braking or extra taxi time. Time is more expensive than just fuel.
9- To what extent are experts the experts who say that conf 3 landings save money?
1- What difference does it make setting landing conf 3 instead of full just at the limit altitude (500 or 1000 ft depending non VMC or IMC)? I think it is negligible with respect to any flighttime not at idle during the approach due to a non optimum TOD and descent. Not to mention the much greater saving of a "more thant optimum descent" such as going low on profile, then "ready for base" and fly some 6 to 10 less NM.
2- does the fuel saving outweights the extra fuel, engine wear and brakes wear due to the extra speed? (in the ecuation of kinetic energy, speed goes squared: a 3% extra speed means a 6% extra energy).
3- I rarely fly conf 3, and i don't like it because i am not used and with light weights thrust is almost idle. And i feel a tailstrike is more likely to occur to me, which is scary.
4- Maybe it is better just to delay flap full until shortly before 1,000 ft, instead of the procedural, when flaps 3, select flaps full
5- a lot of bits of fuel saved can make a big saving in a big airline
6- just one incident (tailstrike) can waste years of saving
7- i would like captains to encourage me to fly conf 3 approaches, but they don`t like it. So i dont like it when a conf 3 is recommended for windshear and gusty winds, because aside from the conditions I have to deal with an unusual attitude and thrust.
8- Extra time taxiing is also a factor, which will occur in many airfields if you use more rwy length. For instance at FCO after landing you may just let it roll with reverse idle to the end. conf 3 that day is fine. But in other airports, the extra speed will be paid either by extra reverse and braking or extra taxi time. Time is more expensive than just fuel.
9- To what extent are experts the experts who say that conf 3 landings save money?
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Originally Posted by captainpaddy
General question: Under what circumstances would you use Flap 3 for landing as opposed to Flap FULL? And why?? Obviously this question would apply to any aircraft where you have a choice of landing flap settings.
Last edited by HazelNuts39; 31st Oct 2010 at 18:42.