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-   -   Flap 3 landings (https://www.pprune.org/tech-log/374831-flap-3-landings.html)

air_cowboy 22nd May 2009 05:33

Flap 3 landings
 
what is the best technique for Flap 3 landings on the A320?

Is tailstrike probability increased?

Robini 24th May 2009 10:00

First of all A320 isn't a plane you normaly should be worried about when it comes
to tailstrike. Bigger bus models may have that ''problem'' but only when takeoff or landing at farely high speeds.

Flaps increase doesn't make that the chanses of tailstrike getting higher, just to increase
the lift coefficient - and thereby possible to land at lower speeds.

In this case when Flaps 3 landings are not so often used as Flaps full you may just keep a higher speed to not stall it. But of course airplanes at higher speeds is much moore controlable than the planes att low speeds, be careful to not overpull it.

FlyUK 24th May 2009 10:11

Sorry Robini, totally disagree.

Flap3 on the 320 makes a HUGE difference to the pitch attitude at landing. The Vref increase is about 4 knots, but you will have about 7ish degrees nose up as opposed to 4 in flap full. Personally don't find it as stable on the approach, but company SOP is F3 unless F full is required.

The 320 IS much more of an issue in the flare with F3 than the 321 in F3. Don't try to hold it off. I find closing the thrust levers at 25R and a tiny little flare about 15R will see you right. If you use a Flap full flare with F3 you will float along at 8 feet! :ok:

Iceman49 24th May 2009 17:30

FlyUK, is the F3 SOP for fuel consevation, and if so, what sort of fuel savings do you realize? Thanks.

guiones 24th May 2009 19:28

Robini:

Refrain from such ignorant posts, read and learn from experienced pilots. Anyone that has been even close to an A320 series A/C knows you got everything backwards; have a little respect for yourself and stick to what you really know, if any in aviation from your posts.

G

Max Angle 24th May 2009 20:45


what sort of fuel savings do you realize? Thanks
We were told it is about 7kg a sector, our lot looked at it and decided it was not worth doing when you took account of perhaps a few more go-arounds due not stable and the increased tail strike risk.

Zippy Monster 24th May 2009 20:56

I fly the 319 and to be honest, my technique isn't much different whether using Flap 3 or full. The only difference I find is the slightly higher nose attitude and the fact the aeroplane feels a little more "slippery", so to speak.

In terms of flare, I still close the thrust levers around the same point, i.e. around the "30" auto call-out (plus or minus a bit depending on head/tailwind conditions of the day); for Flap 3 I find I flare ever so slightly later and obviously a little bit less due to the attitude already being higher. Other than that, I find there's little difference between the two.

I can't really speak for the A320 or 321 but with the higher weight I suspect there might be a bit of a difference? I note the poster above who mentions the huge difference in attitude between F3 and F full on the A320.

Lemurian 25th May 2009 12:37


The 320 IS much more of an issue in the flare with F3 than the 321 in F3. Don't try to hold it off. I find closing the thrust levers at 25R and a tiny little flare about 15R will see you right. If you use a Flap full flare with F3 you will float along at 8 feet!
That's also my experience.
As a matter of fact, the A321 wing trailing edge is different from the rest of the family -Airbus has added a few inches to the chord, therefore on the flap dimensions. The result is a somewhat "flatter" attitude during the approach than on a 320.

martuus 28th May 2009 12:18

In my company, there are 3 of A320s and 7 of A319s, I did not often use Flap 3 landing unless appllied noise restriction in BKK airport.
Pesonel Tech. is little late in thrust reduction ( thrust is not much to keep Vapp ) and my flare is changing pitch not as much as Flap full ( attitude already high so margin for tail strike is not much ).
Every time I do Flap 3 landing, I have to prepare my configuration earlier than Flap full coz' speed not reduce nicely when do ILS Decel. App.

Jimmy Do Little 29th May 2009 17:03


what sort of fuel savings do you realize?
it's closer to 75 kgs saved per landing.

Meikleour 29th May 2009 19:34

On the CFM A319 that I fly the stabilised Flap FULL/Vapp total fuel flow is normally 30-32kgs/min. and Flap3/Vapp gives 26-28kgs/min.

With decellerated approach techniques normally one is only fully spooled up from 1000ft. AAL. - so the question remains - where does your 75kgs /landing come from?!!

Max Angle 29th May 2009 23:03

Those figures tie in very nicely with the 7-8kg that our tech. guys worked out we would save, 75kgs is complete nonsense.

PantLoad 30th May 2009 13:50

Please refer to QRH 2.18A
 
Please refer to QRH 2.18A....Unreliable Speed Indication / ADR Check Proc

This will give you a pretty good idea of pitch angles on approach. Figure
adding four degrees for a nice flare, and I think you'll find, with wings level, you still have almost 2 degrees to spare (assuming struts compressed....struts extended, you have almost 4 degrees to spare).
FCOM 3.03.22 P3 shows how these margins are reduced with increased bank angle.

In theory, you can scrape metal with FLAPS 3, a significant bank angle at touchdown, and improper flare. However, by following
SOP, a FLAPS 3 landing should not force a meeting and subsequent carpet dance in the chief pilot's office.

Fly safe,

PantLoad

dartagnan 30th May 2009 16:00


but company SOP is F3 unless F full is required.
these companies will be sued if accident happen. Normal configuration is Full flaps for landing.

SOP must be full flaps unless F3 is required. that's the correct procedure. Not the reverse. I think some airlines think they save money, less flaps=less drag=less fuel...

ok, but you get less lift=more power to get same amount of lift=more fuel

I doubt you save money with F3.

same thing with N1 taxi to your gate:

1 engine taxi =less power= less fuel(airline thinking!)
ok,...but 1 engine=more power on the engine=more rudder and steering to turn due to asymmetric thrust = more fuel(airbus thinking)....

conclusion: to save real money, follow airbus procedures:ok:.
if an airline was saving money with their "new" procedure, all airlines would do the same.
They don't, so when I hear of a new SOP procedure, we can just laugh at it!

guiones 30th May 2009 21:51

Dartagnan:

Flap 3 landing and 1 engine taxi ARE Airbus procedures.

The option exists for the operator and Capt and it is on the FCOM's.

1 engine taxi is not only fuel savings, but also brakes and engine life.

G

TyroPicard 31st May 2009 10:03

dartagnan..

I think some airlines think they save money, less flaps=less drag=less fuel...
Correct..

ok, but you get less lift=more power to get same amount of lift=more fuel
Complete rubbish!


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