A320 Flap3 landing to save fuel

[vilas]

Hi everyone!
An issue is being discussed in an A320 Asian LCC regarding doing Flap3 landing instead of Flaps full. Actually all are doing it to save some 8kg fuel per landing.The issue is with an airfield with elevation of 2540ft and runway length of 2746mtr. there is an ILS but the glide path is 3.5°. I want to know if there are any European and US carriers who do it. If so are their any conditions when to do and when not to do. Opinions with reasoning are welcome.
Thanks

[Rt Hon Jim Hacker MP]

Could you advise which airfield? Can then run it through FS to see how the settings affect landing distance.

[Check Airman]

At my US company, flap 3 is “encouraged” but most people go with full. It’s at the discretion of the PF. My preference in your situation would be full. We do a few approaches to places where the glide slope is a bit steeper (maybe 3.3, I think), and flap 3 still works fine. I think the major hurdle would be getting stabilised earlier.

That said, 8kg of fuel is less than a rounding error on the gauges. The fuel bowser typically delivers a bit more than the number that’s dialled in. On my last flight, we were over fuelled by about 25 times the 8kg we’re thought to save with flaps 3.

[sekmeth]

European LCC, our standard is flaps full.
But when we want to train, find it operationally relevant or if we just want to have some fun, we fly flaps 3.
(Single engine, its up to the pilots as well if we land with flaps full or flaps 3)

[Nightstop]

Well, we do a landing distance required performance calculation prior to every approach. The result from the EFB has an extra safety factor margin of 15% added. So, provided that Asian LCC does likewise, the EFB result is OK and the approach stable, why not? Flying a Flap 3 approach and landing in the A320 produces a lower noise footprint, saves 9kgs fuel and is recommended by Airbus. Also, we are reminded of our social and environmental responsibility to try and fly as efficiently as possible thereby reducing CO2 emissions, Penguins lives matter too.

[vilas]

It's VEIM. The landing distance is not a problem. Difference between Full and Flap3 is about 150mtrs. I was presented with data of some landings about the ground speed and ROD. invariably in all landings the GS was 150 to 160 kts and.ROD was greater than 1000ft/mt. and unstable approach. Even for 3.5 Glideslope unless the Ground speed is in excess of 170kt the ROD shouldn't be that high. Except landing in tailwind what other reason could be there? And why would anyone land with Flap3 with that Ground speed?

[Check Airman]

According to the FAA ROD table, a 3.5 degree Slope at 150kt will be 925fpm. Passing 3500ft MSL, if you say the Vapp can get up to 160, it wouldn’t take much to get a VS over 1000fpm- but that wouldn’t be unstable in this case.

I guess the TAS and the slope is causing the higher ROD. Flap 3 wouldn’t be my first choice, but it’s doable, I’d think.

blob:https://www.pprune.org/8ad432d7-3a41-4622-816d-11bb1857db4e

http://code7700.com/cdfa.htm

[Rt Hon Jim Hacker MP]

Any idea if the terrain on approach is sloping down towards the threshold? Could it be one of those places which has a lot of thermal activity due to trees/crops?

[Capt Scribble]

Look at the distances and where you want to turn off. If you have to go to the end of the runway, F3 may be useful. If there is a 10 HWC, F3 landing distance is going to be similar to FF with no wind. The idea behind the fuel savings is that in a big company, all those 8kgs add up to a significant $ sum over a year. If you are landing on the limits, then FF allows a bit more room for error.

[Molesworth]

Hi Vilas,
My old company used to 'encourage' F3 landings, quoting fuel saving as a justification. But they were gracious enough to accept that safety came first. So if you are not happy, use F Full. I was never convinced by the fuel saving argument - from what I could find out, the comparison was done for F3 vs Full from 3000 ft on the glideslope - this may well have generated some fuel saving. But doing the approach in F3 and going F Full in time to meet your companies' stabilisation criteria is unlikely to save much fuel at all. The beancounters say that over a fleet of 'x' aircraft, each flying 'y' times per day that generates 'z' dollars savings. So if you don't fancy F3 into a particular airfield on a particular day, that won't dent their figures too much. Be safe. If you are the Commander - take command and do what is safest.

[Check Airman]

Alternatively, if the general preference is for F3, you could always recommend Full for the field in question.

[a5in_the_sim]

Probably all comes down to the type of brakes maintenance contract. “Fixed Price” or “On Condition”. It’s a funny old world.

[Check Airman]

Hi Vilas,
My old company used to 'encourage' F3 landings, quoting fuel saving as a justification. But they were gracious enough to accept that safety came first. So if you are not happy, use F Full. I was never convinced by the fuel saving argument - from what I could find out, the comparison was done for F3 vs Full from 3000 ft on the glideslope - this may well have generated some fuel saving. But doing the approach in F3 and going F Full in time to meet your companies' stabilisation criteria is unlikely to save much fuel at all. The beancounters say that over a fleet of 'x' aircraft, each flying 'y' times per day that generates 'z' dollars savings. So if you don't fancy F3 into a particular airfield on a particular day, that won't dent their figures too much. Be safe. If you are the Commander - take command and do what is safest.

Flaps full at 3000ft?!?! I guess that’s one way to ensure you’re stable. From non-scientific observation, I’d guess most people in my company don’t get to full until 1200-1500, so that halves the fuel saving.

[RexBanner]

The other thing to bear in mind is how much extra fuel you’re burning from missing the exit that you otherwise would have made on the landing roll by using Flap Full. These things are never in isolation.

[Rt Hon Jim Hacker MP]

We used to get continuous hassle from management that our little base didn’t have a big uptake on F3 landings and S/E taxi in.

What they failed to realise was that using F3 would usually involve rolling to the very end and about a 900M taxi in rather than a sharp 90 (not high speed) straight onto the apron.

Have those flights into VEIM been training flights? Could be a factor.

OFDM is a good tool but needs the human touch to make proper sense of the data.

You beat me to it Rex....

[RexBanner]

You beat me to it Rex....

quick on the draw ;) but to be fair you illustrated the point better.

[Check Airman]

I'm all for saving fuel, but isn't it getting a bit academic when we're talking about fuel burn to taxi a few feet when taking one exit vs another? Not to mention the potential lawsuits because of whiplash as people slam on the brakes to make the first exit?

[1201alarm]

F3 or Full is judgement of the crew where I fly the A320. Following things to consider:

Pro Full factors: runway short, wet, contaminated, aircraft very light, ab-initio FO at his very beginning of training, exceptionally when single engine and GA gradient is no factor and runway is short, nearer runway turnoff reachable, speed advisory until late in final (e.g. 160 to 4) to still make it stable upon handbooks gate, lazy pilot

Pro F3 factors: fuel saving (reduction of stable N1 is clearly there, so there must be some markable saving), less noise, long runway, long rollout, standard when single engine, possible windshear (once you go around you're in F2 instead of F3, in WS escape you're in F3 iso Full).

Another big pro F3 is practice: many abnormals require a F3 landing, so you want to be current and skilled in them, you want to be used to the higher pitch picture when going visual, sounds pretty bad to me in the stress of an abnormal to fly the bird the first time in F3. That is why I try to make regular F3 landings, when appropriate according to the criteria above.

Stabilisation is no issue, the A320 is always stable at 1000' when dropping the gear at (10 x GS + threshold alt) for Full, add 300ft for F3.

[RexBanner]

I'm all for saving fuel, but isn't it getting a bit academic when we're talking about fuel burn to taxi a few feet when taking one exit vs another? Not to mention the potential lawsuits because of whiplash as people slam on the brakes to make the first exit?

Well when you’re talking about making a saving of 8kgs but then you then wipe out that saving by taxying a much further distance (think E vs FR at EGKK for instance) then yes it is very relevant. I think the braking to start causing whiplash would be extreme indeed (never have I once experienced it as a passenger or as a crew member and I operate/pax into EGJJ a lot).

[PilotLZ]

I can think of one company which only allows you to land with flaps 3 after you have accumulated certain experience on type. Due to the unusual attitude and higher than normal ROD, there are the inherent risks of a hard landing due to a misjudged flare or even a tailstrike. I have never been close to controllability becoming an issue at the lower speed with flaps full, so the primary arguments in favour remain noise and fuel consumption. 8 kg per flight may not sound significant, but over the lifetime of the aircraft it adds up to quite a number.

As for approach stabilisation, using the flaps as a brake is not a good idea because you will quickly wreck the bearings in their actuators. Unlike the 737 with its massive screwjacks for the flaps, the A320 uses a system of arm actuators which is light and compact but also heavily reliant on said bearings. When the bearings are worn, you can easily feel it with some nasty vibration appearing once the flaps are down.

[Check Airman]

Well when you’re talking about making a saving of 8kgs but then you then wipe out that saving by taxying a much further distance (think E vs FR at EGKK for instance) then yes it is very relevant. I think the braking to start causing whiplash would be extreme indeed (never have I once experienced it as a passenger or as a crew member and I operate/pax into EGJJ a lot).

Looking at Gatwick, E vs FR is exactly what I'd consider negligible for fuel burn, after having spent a few hours up at altitude burning 100lb a minute. It adds what, an extra 45 seconds to the flight? How does that compare to not getting that step climb at exactly the right spot, or flying 2000ft higher or lower for turbulence? Get to the gate too soon, and the ground staff isn't ready anyway

As I said earlier, my opinion is that the taxi fuel saving there is academic.

[RexBanner]

Don’t want to start getting too far into it or splitting hairs but regular visitors to Gatwick will know that the difference between making E or FR can easily add quite a significant amount of time onto your taxy time depending on the traffic situation. I completely agree with your point that it’s peanuts but if you’re interested in the minutiae of specifically choosing Flap 3 in order to save 8kg fuel but then you miss a turnoff that then costs you more than 8kgs fuel in the process then that’s missing the bigger picture IMHO.

[Check Airman]

Don’t want to start getting too far into it or splitting hairs but regular visitors to Gatwick will know that the difference between making E or FR can easily add quite a significant amount of time onto your taxy time depending on the traffic situation. I completely agree with your point that it’s peanuts but if you’re interested in the minutiae of specifically choosing Flap 3 in order to save 8kg fuel but then you miss a turnoff that then costs you more than 8kgs fuel in the process then that’s missing the bigger picture IMHO.

Never been to LGW, but agree with your last point. If opting for F3 leads to a significantly longer taxi time, you’ve lost the plot.

[C172Navigator]

The difficulty is handing. Flap 3 often feels pitchy and rolls quite a lot in turbulence on a warm air day. So landing at this high elevation with a 3.5 degree slope would be flap full for me. You might have the runway performance but you still need a stable approach.

[FlightDetent]

vilas I'm a great fan of not burning more fuel than needed. Tried F3 when it made sense, now and then.

Wise opinions above already, it's a very hard task to calculate whether or not will F3 bring real fuel savings (extended taxi time), or burn more money on reversers use et al. The opinion I like the most, is to educate the pilot pool and give them the option. Not to force it into standard practice.

There is one case I know of, where it would be a good and reasonable STANDARD option, In LIMC/MXP, 98 % of the time the landing direction is northbound. A large LoCo using predominantly A319s is based in the northern terminal T2 https://www.google.com/maps/search/Malpensa+/@45.6480086,8.7212175,1563m/data=!3m1!1e3. Plain to see, using F3, idle REV, no ABRK will get you to the gate quickest, cheapest and greenest.

In VEIM the taxi configuration looks inviting. My first choice would be NO, not as a standard. Mostly due to steeper glide, crew proficiency must be considered. As an educated choice, why not, I would happily let the FO fly it.


Check Airman One minute taxi time burns 11 kgs of fuel (+2 for APU), completely no strings attached. Engine-hours also a factor if. The alleged F3 savings on approach are 6-8 kgs, and people are discussing the latter.

[dream747]

I believe we’ve been talking about the A319s/A320s in general here, what about the A321s? We don’t have A321s in our fleet, neither have I flown one. I for one don’t see tailstrike as a significant risk on the A319s/A320s, but out of curiosity, any real risks or difference when doing it on the A321?

Aside from fuel savings, another good reason to get well acquainted with Flaps 3 landings whenever you can is you never know when you’ll have to do one in Direct Law one day.

[Check Airman]

I believe we’ve been talking about the A319s/A320s in general here, what about the A321s? We don’t have A321s in our fleet, neither have I flown one. I for one don’t see tailstrike as a significant risk on the A319s/A320s, but out of curiosity, any real risks or difference when doing it on the A321?

Aside from fuel savings, another good reason to get well acquainted with Flaps 3 landings whenever you can is you never know when you’ll have to do one in Direct Law one day.

The 321 is odd in that the tail clearance is ever so slightly better with F3. Still a higher approach speed though. Easiest of the 3 to land, in my opinion. I haven't flown the A318.

FlightDetent I do my part by not starting the APU unreasonably early.

[Cropduster]

I did an analysis many years ago on this exact question. The brake wear is a negligible item as the brakes, while expensive, last a very long time. There is some reduction in flap drive wear costs associated with Config.3 landings. The kicker is the tire costs - 10% greater than with a Config. Full landing. Back then, the tire wear was the same as the fuel saving. With the low cost of fuel now I would be pretty certain that it costs more overall to land Config. 3 than Config Full. YMMV.

[172_driver]

I believe I speak for the majority when I say flap 30 is the norm on the 737, flap 40 only for performance. My friends on the 320 seem to prefer flap full over flap 3 (..is that how you say it? or config 3?) as standard. I have always wondered why it's become like that....

[KayPam]

At my US company, flap 3 is “encouraged” but most people go with full. It’s at the discretion of the PF. My preference in your situation would be full. We do a few approaches to places where the glide slope is a bit steeper (maybe 3.3, I think), and flap 3 still works fine. I think the major hurdle would be getting stabilised earlier.

That said, 8kg of fuel is less than a rounding error on the gauges. The fuel bowser typically delivers a bit more than the number that’s dialled in. On my last flight, we were over fuelled by about 25 times the 8kg we’re thought to save with flaps 3.
The fact that you can't measure it doesn't mean it doesn't exist.
It will be measurable if a consequent number of pilots do this type of eco-flying.
(And, of course, if the fuel saving is not counterbalanced by longer taxi-in and/or more use of reverse thrust..)

[sonicbum]

Hi everyone!
An issue is being discussed in an A320 Asian LCC regarding doing Flap3 landing instead of Flaps full. Actually all are doing it to save some 8kg fuel per landing.The issue is with an airfield with elevation of 2540ft and runway length of 2746mtr. there is an ILS but the glide path is 3.5°. I want to know if there are any European and US carriers who do it. If so are their any conditions when to do and when not to do. Opinions with reasoning are welcome.
Thanks

Hi vilas,

European flag carrier. We used to have a stable approach criteria being not exceeding 1200 ft/min below 1000 ft AAL but that was eventually changed a few years back to the aircraft established on the vertical path with no specific RoD, hence the above combination would be possible, RoD wise.
We do not have set limitations for flaps config selection for CAT A and B aerodromes ; basically you choose whatever makes sense trying to save fuel as much as possible.
With the above scenario, unless it would be a CAT C aerodrome with specific instructions, I guess 90% + of the crew would elect CONF FULL, especially in hot weather.

[FlightDetent]

I believe I speak for the majority when I say flap 30 is the norm on the 737, flap 40 only for performance. My friends on the 320 seem to prefer flap full over flap 3 (..is that how you say it? or config 3?) as standard. I have always wondered why it's become like that....Different landscape, really. Immediate return OEI: (*)
- ISA SL -> up to 88 tonnes the standard flap is full.
- 4000 ft @ 40° -> 77 max for standard flap full (77 = MTOW).

F3 is awkward. But you have a point, perhaps one day everyone will switch over, most likely for noise. As witnessed by the valuable insight here, there is no practical benefit (**) although for a narrowly minded KPIs a case can be made and had been repeatedly.

IIRC on IAE engines the angle for flaps full was increased to a greater deflection, to allow higher N1 in order to assure TOGA engine spool-up characteristics. Heard it here, FCOM confirms the geometry.

(*) Airbus cheating again, QRH: MAX WEIGHT FOR LANDING IN CONF FULL again has data for CS-25 gradient 2,1% (non LVO), whereas in the real-life 2,5% is needed to match PANS-OPS.
(**) if approaching stable approach gate 1000 and too fast, a dirty trick is to change for F3 and move the goalposts. Let's talk what's wrong with some FDM / FOQA concepts ..., rather not.

[Peter Pilot]

Yawn... you lot need to get back to work.

[guy_incognito]

Another big pro F3 is practice: many abnormals require a F3 landing, so you want to be current and skilled in them, you want to be used to the higher pitch picture when going visual, sounds pretty bad to me in the stress of an abnormal to fly the bird the first time in F3. That is why I try to make regular F3 landings, when appropriate according to the criteria above..

Heard that line trotted out before. It's tosh, quite frankly. If you're doing a CONF3 approach due to ECAM, by definition it won't be a "normal" CONF3 approach. The approach speed will be higher due to a Vref correction so the "picture" won't look the same as in a normal CONF3 approach anyway, you'll probably be dealing with other configuration issues which mean the handling won't be the same as in normal ops etc.

[Flapsupbedsdown]

Could you advise which airfield? Can then run it through FS to see how the settings affect landing distance.

FS?? What is that?

[dream747]

FS?? What is that?

I believe it refers to FlySmart. The Airbus EFB.

[vilas]

To put it together Flap3 does save fuel. The pros and cons for steep approach
1. In A320 Flap3 landing is not an issue because Flap3 is mandatory for abnormal landings.
2. Landing distance is not an issue as Flap3 takes appx.150mtrs extra. Also the reference WT is MLW which may not be the case mostly.
4. From stabilization point of view only the ground speed can be limiting because in turn it will breach ROD criteria.
5. This should only come in play with tailwind which also the most penalizing for landing distance.
For stabilization tailwind may have to be avoided and opposite runway can be chosen if possible. Off course fuel saving can be done on another day.

[CaptainMongo]

We have a procedure - wind shear precautions - which is used when wind shear probability may exist, but doesn’t warrant avoidance. This procedure, among other things, requires a Flap3 landing. I recall one flight where it was appropriate to use the precautions and told the FO (who was PF) that he would do a F3 landing. He looked at me bug eyed. (That isn’t what we want to see from a fully qualified pilot performing a normal procedure.)

Our fleet encourages F3 landing for fuel savings and reduced noise footprint. From my experience, less than 5% of pilots fly them with any regularity.

[Check Airman]

I believe I speak for the majority when I say flap 30 is the norm on the 737, flap 40 only for performance. My friends on the 320 seem to prefer flap full over flap 3 (..is that how you say it? or config 3?) as standard. I have always wondered why it's become like that....

Flaps full is more stable, and the default landing config is full- flap 3 means increased workload :E

[vilas]

We have a procedure - wind shear precautions - which is used when wind shear probability may exist, but doesn’t warrant avoidance. This procedure, among other things, requires a Flap3 landing.
CM
It is a bit paradoxical in Airbus that Flap3 gives better performance in wind sheer but Flap full gives better handling in turbulence. It's due reduced gain in flaps full. Controls are more sensitive in Flap3

[Weapons Grade]

Flaps full is more stable, and the default landing config is full- flap 3 means increased workload :E

Has anyone else noticed in the A320, that when selecting F-FULL which generally occurs at about 1200ft AGL, there is ~1.0 deg (or more) pitch up? This means that, when hand-flying an approach and to remain on the required vertical path, a counter-action is required by the PF.
If AP is engaged with FPA -x.x (say -3.0) for vertical guidance, then after F-FULL selected, the FPA needs to be adjusted to -4.0 to retain the correct vertical path. This would be an increase in work-load particularly approaching the 1000ft stabile approach criteria, not experienced with F-3 approaches.

Quote: It is a bit paradoxical in Airbus that Flap3 gives better performance in wind sheer but Flap full gives better handling in turbulence. It's due reduced gain in flaps full. Controls are more sensitive in Flap3.

Can someone provide the reference to the FBW architecture for reduced gain in F-FULL, which would make F-FULL less sensitive than F-3? From my experience, F-3 gives better handling and response in turbulence, than using F-FULL (less drag with F-3).

[vilas]

From my experience, F-3 gives better handling and response in turbulence, than using F-FULL (less drag with F-3). That's why I said paradoxical
FCTM SUPPLEMENTARY PROCEDURES ADVERSE WEATHER
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/988x662/screenshot_20200620_132115_2_182260e9a5d12a2ab6531348179f90d d046dded3.png

[Goldenrivett]

Can someone provide the reference to the FBW architecture for reduced gain in F-FULL, which would make F-FULL less sensitive than F-3? From my experience, F-3 gives better handling and response in turbulence, than using F-FULL (less drag with F-3).
Hi Weapons Grade,

This picture Roll Kinematics (http://www.blackholes.org.uk/PP/Roll%20Kinematics.png) (from an incident report of A320 with handling difficulties in Hong Kong many years ago) shows the change in roll spoiler response with handle at Flaps Full.

Initially for roll orders up to about 7 degrees, the spoilers are far less responsive (but are activated 3 degrees earlier than CONF 3)
Beyond 7 degrees and up to about 11 degrees of roll order, the spoilers are a bit more responsive but still only about half that of CONF 3. (11 degrees of roll order v 6 degrees of roll order for 10 degrees of spoiler deflection)
Beyond 11 degrees the spoilers become more sensitive and full authority is restored at 20 degrees roll order.

I can't find the report just yet, (see Aviation Safety Net (https://aviation-safety.net/wikibase/140547)) but from memory Airbus changed the ECAM procedure.
"APPR PROC S/F JAMMED PROC APPLY FOR LDG (IF FLAPS ≤ 3) USE FLAP 3
This line is replaced by “FOR LDG : USE FLAP 3” when CONF 3 is selected, as a reminder
FLAPS (IF FLAPS>3) KEEP CONF FULL."

[vilas]

Thank you Golden I wanted to post that but felt lazy.

[Saint-Ex]

What about brakes and tyre wear?

[vilas]

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1920x1080/screenshot_20200621_221925_984fc5c7a872480b10341183c5dce3726 49667f2.png
Interesting information about landing gear warnings

[Escape Path]

In our company we are encouraged to land Conf 3, it is our first option to land, even on a wet (but not contaminated) runway, provided we run a calculation with runway condition “medium to poor” and take no credit for reverse. However, we do have some high altitude airports; main base is at 8300ft, our most frequent destination is at 7000, and we have everything between those and airports right at MSL. I do try to save fuel when possible (part of the job description now, I suppose), but I try to put common sense on top, so far as decision making goes, and I’ve tried to made it simple for myself.

So here goes: land with Conf 3 (+ idle rev) if no particular weather phenomenon present, I.e, no tailwind, no massive shower, no chance of shear and, if landing at one of those high alt airports (read those two mentioned above) resulting Vapp no higher than 140 (mainly for the GS/VS relation mentioned above, and also to take care of the brake temp, since our turnarounds are short). I’ll even land conf 3 with a wet (but not contaminated) runway, if no other relevant factor is present (no high winds, no heavy shower). However: runway with active heavy rain showers (we fly in the Caribbean) or runway too wet (as in “massive rain shower just ended”) will see me use conf full + max rev. Tailwind? Too heavy? Atmosphere too bumpy (like on hot days)? Conf full is my choice.

I do have a nitpick, which I will present to you here for judgement/correction/confirmation, and that is the abrk setting. Company says this is the first item to be modified in the landing conf (before flaps and rev, in that order) for $ome rea$on I $u$pect, which would mean that if I choose to land with flaps full + rev, it’s because I already have abrk on medium. However, when landing in seriously wet runways I use conf full, rev but abrk on low. My reason for this is that I know (because of Lauda Air 767) that reversers destroy lift, and abrk at medium will sometimes make controllability a bit harder once on ground (on one occasion I even had to disengage it as it made the airplane veer left and correcting with pedals wasn’t enough). Abrk low, in my experience, will see the airplane roll down nice and easy with no weird pulls to either side and control will be easier. Any comments on this practice?

Regards!

[vilas]

Escape Path
Without abnormality Conf3 landing is for fuel saving. Two other factors compet with this are maintenance of reverse and brakes wear. According to an Airbus study on the subject brake oxidation and replacement cost can nullify fuel saving. Therefore the ideal combination is Conf3, Reverse idle and A/B low. If this combination doesn't suit the landing distance then it is modified in the same order. First go for Flap full if further reduction in LD is required then use reverse full and higher A/B is the last priority. In slippery conditions A/B is better for symmetrical application. In your example could be one side brakes catching. Regards

[Check Airman]

I’m also not a fan of medium unless it’s necessary. It’s a bit too aggressive. At times, low is too slow to act though. I do like that in the NEOs, low gives a bit better performance. Just right, I think.

[Escape Path]

Escape Path
If this combination doesn't suit the landing distance then it is modified in the same order. First go for Flap full if further reduction in LD is required then use reverse full and higher A/B is the last priority.

Thank you for your insight vilas. Funny thing, our company asks us to modify conf almost the other way around: Abrk, then flaps, then rev. I know there are different “brake maintenance packages”, I’d guess it’s got something to do with it.

I’m also not a fan of medium unless it’s necessary. It’s a bit too aggressive. At times, low is too slow to act though

My thoughts exactly. I’d rather have low and then use manual braking to make my turn-off

[vilas]

Thank you for your insight vilas. Funny thing, our company asks us to modify conf almost the other way around: Abrk, then flaps, then rev. I know there are different “brake maintenance packages”, I’d guess it’s got something to do with it.
My thoughts exactly. I’d rather have low and then use manual braking to make my turn-off
Actually something similar is happening in Indian context. One carrier is retaining flap3 but selecting A/B medium to stay within FLD. But Airbus doesn't recommend that. I will check with the airline to see
​​if they have some other factor to do so. Also Airbus doesn't recommend taking.over manual braking from low i.e. from fuel saving point.

[Fursty Ferret]

Everything depends on the airline and the maintenance packages they use.

Airline A might find it cheaper to hammer the brakes instead of the engines. Airline B might be vice-versa and prefer flap full and max reverse. Airline C might be using different brake material.

The reality is that 90% of carbon brake wear happens on taxi-out.

[Escape Path]

Also Airbus doesn't recommend taking.over manual braking from low i.e. from fuel saving point.

I failed to understand this connection between fuel and brakes. May I ask you for some further clarification?

The reality is that 90% of carbon brake wear happens on taxi-out.

More brake applications during this phase, I suppose?

[vilas]

EP
Airbus considers fuel Vs brakes oxidation and replacement. According to them economy from Flap3 landing is when you use AB low. In medium or overtaking manually results in high temperatures and repeated exposure to high temperature leads to thermal oxidation and may be fracture requiring replacement which overtakes the cost of fuel saved.

[hans brinker]

More brake applications during this phase, I suppose?

Apparently more related to high wear at lower temperatures.

https://code7700.com/pdfs/carbon_brakes_airbus.pdf

[Escape Path]

Thank you for your input vilas.

hans bringer: Interesting article. Thanks for sharing. It seems like it is a matter of both, actually. Both low temperatures and brake applications seems to be the two factors with more importance regarding brake wear.

It also seems I was screwing it up with these brake temp thing; I HATE the sound of brake fans left running thru the turnaround, and I always found that if I turned it on at the start of the pushback I’d be with cool enough (100-ish) brakes when taking off. This, of course, means that I’ve been taxiing out with the brakes at its highest wear rate zone (ours are MB if I recall). Food for thought...

As a side question: Is the brake manufacturer the one on the wheel rim? Or can the rims and the brakes be from different manufacturers?

[nervous_novice]

Everything depends on the airline and the maintenance packages they use.

Airline A might find it cheaper to hammer the brakes instead of the engines. Airline B might be vice-versa and prefer flap full and max reverse. Airline C might be using different brake material.

The reality is that 90% of carbon brake wear happens on taxi-out.

I agree yeah, as a former LCC operator With regards to kinetic energy, a flap 3 landing and an associated vapp increase ultimately v in the following of 1/2mv squared will result in a far higher kinetic energy which been dissipated as thermal energy and thus a brake energy increase . Regards ,Nervous .

[Uplinker]

I believe I speak for the majority when I say flap 30 is the norm on the 737, flap 40 only for performance. My friends on the 320 seem to prefer flap full over flap 3 (..is that how you say it? or config 3?) as standard. I have always wondered why it's become like that....

It is spoken: "Flap three". (I heard of one TRE who insisted on "Flaps three" :ugh::mad: )

From memory the B737 has 8 or 9 flap lever positions: 1,2,5,10,15,25,30,40. (can't remember if there is also a 0.5° position?).

Airbus FBW family has just 4 flap lever positions. I imagine the Airbus design engineers calculated that they didn't need so many config options, maybe as a result of the wing or the FBW, so they could massively simplify the system and the flight operation? Normal landings are with Flap full, and Flap three used on very turbulent days.

I think it is getting a bit desperate when crews are being asked to modify their landing performance just to save 8kg of fuel. Of course it could theoretically add up over a year, but that is more a spreadsheet artifact, and as Check Airman points out; that sort of small amount can easily get lost in the 'noise'. Just get the marketing department to earn their salary and work harder to attract more passengers !

I mean, operators could just as easily demand that pilots' flight bags weigh no more than X kg, or that crew themselves weigh no more than X !! Well, it would theoretically save fuel.......

On Airbus I think four positions: 'Low, Medium, High (and Max)' autobrake would have been helpful on the A320 family; to give us three normal autobraking options instead of only two: with the new Medium being slightly less than it is now, and the new High being slightly more than Medium is now. There is a space on the panel for one extra PB, so it might have been considered?

[FlightDetent]

:) As in 1-2-3-max-RTO? Could not agree more.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/250x292/snippetabrk_efe84d06190d85ba83dbf1784cf8210259e95b55.png

[vilas]

For the same weight Boeing speeds are higher than Airbus. So like so many compromises in 737 they have given one in braking as well.

[FlightDetent]

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/585x453/borgbus_436020748e5d262b888327e8e975f10cceecd353.png

[Fursty Ferret]

Should just be a volume control. That goes up to 11, of course...

Can’t count the number of times I’ve wanted “lodium” setting.

[Check Airman]

:) As in 1-2-3-max-RTO? Could not agree more.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/250x292/snippetabrk_efe84d06190d85ba83dbf1784cf8210259e95b55.png

LOL

you win the Internet today, sir

[Check Airman]

Should just be a volume control. That goes up to 11, of course...

Can’t count the number of times I’ve wanted “lodium” setting.

I believe what you’re looking for is a Douglas

blob:https://www.pprune.org/ab10eb80-8c41-40e0-9128-b68b4343eea3

[Check Airman]

It is spoken: "Flap three". (I heard of one TRE who insisted on "Flaps three" :ugh::mad: )


Will somebody be considered persona non grata if he admits to saying this? Asking for a friend:)

[Uplinker]

Not by me :)

I was told of a TRE in our company conducting a SIM session and insisting that one should say 'flaps.....', not 'flap.....'

I think there are rather more important things to worry about than that.

@FlightDetent; yes, the Boeing auto-brake selector is what I had in mind.

[Check Airman]

That reminds me of one company that insisted the call out for the fully retracted position of the flaps was “zero” and not “up”, because the lever said “0”.

[vilas]

That reminds me of one company that insisted the call out for the fully retracted position of the flaps was “zero” and not “up”, because the lever said “0”.
That's the way it is in airbus. That's the way the manufacturer teaches. Flaps up is in Boeing. It may appear trivial but slowly this creeps in other things as well. It's problematic where there are expats or pilots transitioned different aircaft each adding his flavor. Then a new human factor is being conceived.

[Check Airman]

After I wrote that, I started to wonder what was written on the lever on the bus. We say “flap/flaps up”. Haven’t come across a language problem so far (unless Texan is a language), but point taken.

[Max Angle]

It is inconsistent, the lever says FLAPS but the label on the screen says FLAP.

[FlightDetent]

It is inconsistent, the lever says FLAPS but the label on the screen says FLAP.
​​Because on the E/WD it shows the selected position, whereas the selector and its scale offers multiple options?

Sounds a far stretch even by my standards, perhaps it is a French thing.

[compressor stall]

I couldn’t give a rats about FLAP or FLAPS (although Airbus want the plural as per the FCOM), but I do care about Zero vs UP.

You call the position of the Flap, 0,1,2,3 Full.

Gear is binary, DOWN or UP.

Also, to mind there’s less chance of confusion or mishearing. The word UP or DOWN can only be attributed to one action.

That said I acknowledge that Flaps UP has been around for years in the B camp. Not saying it’s wrong, just that it can only be better having a verb associated with one item. After all the flap lever is a flap shape and the gear lever a wheel shape for a reason.

[FlightDetent]

That is an important angle. There was an action slip incident where upon getting airborne the PM retracted the flaps instead of raising the gear.

​​Airbuses more often than not depart with F=1, imagine the statistics if the call for retracting them had been Flaps UP as opposed to today's Flaps ZERO.

[WhatShortage]

That is an important angle. There was an action slip incident where upon getting airborne the PM retracted the flaps instead of raising the gear.

​​Airbuses more often than not depart with F=1, imagine the statistics if the call for retracting them had been Flaps UP as opposed to today's Flaps ZERO.
Won't crash neither happen anything dangerous.. Flaps zero at not the proper speed? No problem, the bus is in charge and won't do "much"

[Jwscud]

You might get quite an interesting and unexpected demonstration of low speed protections and alpha lock 😬

[Escape Path]

Won't crash neither happen anything dangerous.. Flaps zero at not the proper speed? No problem, the bus is in charge and won't do "much"

I’d be hesitant to describe an airplane failing to respond to your “alpha prot kicked in”-panic-induced nose up input so near to the ground as “no problem”. Alpha prot at around 200ft not dangerous? Jeez, I wouldn’t know about that...

[Check Airman]

That is an important angle. There was an action slip incident where upon getting airborne the PM retracted the flaps instead of raising the gear.

​​Airbuses more often than not depart with F=1, imagine the statistics if the call for retracting them had been Flaps UP as opposed to today's Flaps ZERO.

While acknowledging my personal bias, I'll agree that there may be something there. I'd argue though, that it's pretty unlikely that it'll be a problem given that hundreds if not thousands of flights operate(d) every day with the "flaps up" call.

[Check Airman]

I couldn’t give a rats about FLAP or FLAPS (although Airbus want the plural as per the FCOM), but I do care about Zero vs UP.

You call the position of the Flap, 0,1,2,3 Full.

Gear is binary, DOWN or UP.

Also, to mind there’s less chance of confusion or mishearing. The word UP or DOWN can only be attributed to one action.

That said I acknowledge that Flaps UP has been around for years in the B camp. Not saying it’s wrong, just that it can only be better having a verb associated with one item. After all the flap lever is a flap shape and the gear lever a wheel shape for a reason.

A large US airline used to accompany the gear call with a hand motion by the PF. It's no longer done though.

[FlightDetent]

Guess you're right.

[vilas]

FD
a very good point.
Won't crash neither happen anything dangerous.. Flaps zero at not the proper speed? No problem, the bus is in charge and won't do "much" Yes! unless it is. Combine windsheer to that and it will happen. In the investigation the ubiquitous human factor will pop up. Bernard Ziegler said "my aircraft is so simple to control it will even prevent bad Pilots from making a mistake" didn't take long to prove him wrong did it?