A320: flaps full or flaps 3+speed brakes?

[antonilo]

Hi all,
I´ve a question...in the case of being above the profile in the approach (too high) what would be more effective in order to correct that deviation...the use of flaps3 plus full speed brakes or the use of full flaps?
Thanks for your answers

[mutt]

If you are slow enough for CONF3, do you think that its wise to use FULL Speedbrakes?

Mutt

[CABUS]

Personally I would use full flap and capture from above but if you are needing speed brake and full flap to capture a glide its probabaly a bit unstable.

[fatboy slim]

Yes, I think CONF2, speedbrake and VS -1500 until G/S* then put the brake away and take the rest of the flap to slow down. I can't remember having got in a position that needed F3 and speedbrake. I think thats a go-around and try again situation. Althought I only fly 321s.

[CEJM]

It also depends if you have the autopilot on or off. With the autopilot on you only get just over half spoiler deflection anyway. However with the autopilot off you will get full spoiler deflection.

[Dream Land]

Config3 and speedbrake.

[antonilo]

Ok,
The situation is the following: visual app, A/P off, A/T off, F/D´s off.
You are too high and you don´t want to perform a go around so you want to descent as much as you can...
Forget about excesive rate near the ground :eek: or pax confort:yuk:. My question is only about the aircraft performance.:confused:

[Gary Lager]

The A/THR can misbehave on finals if speed brake is used with flap during the approach and G/S tracking during speedbrake extension/retraction can be very poor, leading to some 'interesting' pitch attitudes and rates of descent (and historically many destabilised approaches) as the aircraft reacts to the significant trim changes.


Gear down ASAP to decelerate the aircraft rapidly below VFE, Flaps to FULL, 160 kts until reestabilished. Or throw it away and do it again properly, and don't be in such a hurry to disconnect the automatics next time!

[Founder]

Almost every approach we do here in Turkey is ILS capture from above because of these darn ATC are keeping us high and bringing us in too tight...

Standard is always gear down asap and then config full asap! That's with A321's...

[electricdeathjet]

Just for info: you CAN get full speed brakes with A/P on in the 319...

But I personally find them quite useless when in config 3 or more.

I heard side slipping is great fun in the bus (you did say ignoring pax comfort)

[CEJM]

electricdeathjet,

On the A320 you can't get full speed brake with the A/P engaged. Seems that the A319 is the same as the A321 as you can indeed get full speed brake with A/P on.

However the name of the thread implies that the thread starter was referring to the A320. :ok:

[JSF1]

A321's speedbrake is inhibited with config 3 & full anyway, so kinda rules that one out.

[Ivan aromer]

"DO NOT side slip the 'bus the pods are not designed for it". so speaketh the airbus top test man (several years ago)

[Olabade]

Hey,

Use speedbrake to slow down to vfe -> conf full speed 160 with idle power gives high enough steep rates. Anything more would be too unstable.

Use of speedbrakes with conf full is not allowed (and with A321 in conf 3 too).

Olabade

[flyingins]

If you can see that you're high on any sort of approach, but particularly a visual approach, it is more effiacious to select "VS 0", configure to CONF FULL, Gear Down and reduce speed to Vapp (this occurs quite quickly when level), then push forward to achieve a rate of descent which will re-capture your approach path to the runway by an appropriate altitude (to allow the engines to "spool up" by 500' AGL). Close attention must be paid to rates of descent approaching the ground (as a guide, VS-2000 at 2000', -1500 at 1500' & no more than -1000 below 1000').

It seems utterly counter-intuitive but given that CONF FULL is basically all drag and you've reduced your speed across the ground to an absolute minimum (Vapp), pushing forward at that point will provide the steepest angle of descent with all other factors required for landing (except Vapp since your speed will increase to not above 177 knots!) already accomplished.

This technique is best applied to visual approaches, since ILS, LLZ, GPS, VOR and NDB approaches (if conducted in IMC) have a higher "stable" requirement; in my company, we must be stable by 1000'AGL on an ILS, and the earlier of 2000' or the FAF on NPA's. If you're high enough to have to try to correct to profile using any unusual technique in IMC, you'll almost certainly be better off discontinuing the approach, or doing a go-around!

[FlightDirector7]

Flaps 2 with the gear down and speed selected 190 knots, in OPEN DES, as thrust will be idle, she'll dive believe me. Tried and tested :ok:. You can correct any deviation. Ofcourse, this does not apply to being already established on the ILS, this only applies if you've been given very short radar vectors very suddenly. As mentioned in previous posts, especially in the A320, the best dive technique when you're far out is select speed 300 or 280, disconnect the AP and use full speed brakes. Spoiler deflection with the AP disengaged is 20 deg for spoiler 2 and 40 deg for spoilers 3 & 4, unlike 12.5 deg and 25 deg respectively when the AP is engaged (A320 only). A321, the maximum spoiler deflection is 25 deg whether AP engaged or not.

When trying to catch the glide from above, best rate of descent is V/S -1500 (AT THE MOST, or anything less) else u'll go past your Vfe next and you wont be able to configure :uhoh: :yuk:

[EMIT]

To CABUS, post #3.

Just a reminder that in A-320, speedbrakes are (not PROhibited, but) INhibited in Full Flaps, meaning, you can pull the speedbrake handle back, but the panels will stay flush with the wing!

To Antonilo:
If it is during a visual approach, consider the following possibilities:
Extend downwind a bit,
Make the turn to final a bit wide, so you overshoot finals a bit, basically the S-turn that you make gives you some extra ground distance,
Extend the gear earlier (out of normal sequence),
Keep speedbrakes out while deploying flaps (as stated earlier, they will not deploy with Full Flaps).

All those actions should be taken IN TIME, discovering that you are too high and too fast at 3 miles final means that you screwed up earlier in the approach and you should make a go-around.
Consider this: 300 ft per mile is the norm (320 ft to be precise), so 30 nm to go at 10.000 is normal, 20 nm remaining at 10.000 ft can be handled.
The same relative error, 1.500 ft at 3 miles, instead of the required 1.000 ft at 3 miles, cannot be corrected anymore.


(Edited for a typo)

[FlightDetent]

CONF 3, gear down, landing lights out, speed brake full - A320, managed speed. Aim to be stable at 1000, if not at 500 GA is mandatory. KISS & and works like charm.

[Admiral346]

I agree with FD7, and it also goes for A330/340.

Flaps 2, gear down and Speedbrake with a selected speed and open descent is the only way to even make it from the downwind to final in SFO. They did it to me on a regular basis.

Nic

[antonilo]

Thanks everybody for the answers,
Most of you tell me that it´s better to extend downwind or use of flaps 3 or whatever to finally make a stabllished app.
The thing is that we fly many times positional fligths with no passengers so we can try "other things" so if I´m to high I like to fly feeling what can I expect from the aircraft (with safety of course)
My procedure usually consists in reducing speed and descent with flap 3 and speed brakes full (gear down aswell), what I´ve always think that was better than full flaps.
But recently I´ve flown with two guys that told me the opposite, and one of them told me that speed brakes are usefull at high speeds, but at lower speeds they loss effetiveness so is better to use flaps full.
I will ask my question in other way:
***What offers more drag, full speed brakes OR full flaps in comparison with 3?***
Sorry for extending so much...

[Metro man]

Just for info: you CAN get full speed brakes with A/P on in the 319...

Yes but they only move to half the extension of the A320s speed brakes in the full position, probably why they seem ineffective. Don't know about the A321.

[LanFranc]

Over the last 11 years and 7500 hours on the A320 I have tabulated data on this very subject many many times.

From what I have observed, repeat, from what I have observed, A/P off, gear down, flaps 3, full speedbrake and selected speed 170 gives best descent angle. Plan about 1,000ft per mile.

One piece of advice though. If you ever plan on doing this, work you way into it gradually. It takes considerable handling technique to transition back to "stabilized" parameters.

[antonilo]

Thats my answer Lanfranc. Thanks

[yowdude]

"Flaps 2 with the gear down and speed selected 190 knots, in OPEN DES, as thrust will be idle, she'll dive believe me. Tried and tested :ok:. You can correct any deviation. Ofcourse, this does not apply to being already established on the ILS, this only applies if you've been given very short radar vectors very suddenly. As mentioned in previous posts, especially in the A320, the best dive technique when you're far out is select speed 300 or 280, disconnect the AP and use full speed brakes. Spoiler deflection with the AP disengaged is 20 deg for spoiler 2 and 40 deg for spoilers 3 & 4, unlike 12.5 deg and 25 deg respectively when the AP is engaged (A320 only). A321, the maximum spoiler deflection is 25 deg whether AP engaged or not."

if you require more then your unstabilized already, just go around and try again:ok:

[dkz]

For the fastest descent before the ILS the best is described by FD7, Flaps 2, gear down, speedbrake (without A/P) and it dives pretty steep.

After the LOC capture i use FULL flaps, feels like more drag. Also i like to be configured before 1000ft if i'm visual (not stabilised but in landing conf with a little more speed, and of course stabilised at 500ft).

On the 320 in low speed the speedbrakes don't perform quite well and moving the speedbrake lever only gives you sh*tty trim changes.

(Personal view)

[Antunes]

I'd take the Flaps 2, Open Descent, with full/half speedbrakes (depending on a/c type), gear down and speed around 190/195kt (only on calm air)

If ATC holds you at an altitude, try to reduce the speed as much as you can, so that, when you are cleared to a lower altitude, you lose altitude faster by exchanging altitude into speed.

Use V/S function wisely, because the system logic, when using this mode, is to achieve the selected rate by any means. Speed may go way above target and a flap overspeed situation may occur... :{

And, as usual, stabilized approach at 1000' (IMC) / 500' (VMC)... or go-around :ok:

[A-3TWENTY]

Airbus does nor recommend the use of speedbrake on finals...

FCOM 3

[groundfloor]

Glad to see some other pilots out there called "Rudel" by ATC...

17 Nm to touchdown then 5 seconds later they turn you base and your name is now Rudel as you flew Stuka`s - gear down, flap down, slow down, go down...:}.

[zeus_737]

i fly all three types... and in my limited experience i can tell u...
flap 3 is a lift config..hence considered for takeoff.
flap full is a drag config.. hence used only for landing

in addition... use of speed brakes not recommened in the appch phase by airbus as per fcom 3....

besides at a speed of 140 kts vapp... so average vls of 155 with speed brakes exteneded and flaps 3 would give u much lesser drag than 140 kts vapp and flaps full selected with propably a speed selected of 155 or 160...
she comes down like a rock.. minus the headache of having to stow the speed brakes and watch ur profile simultaneously... once stabilised at 1000' ifr or 500' vfr u can take it frm there else go around..
hope this helps.

[dweeks]

175 KTS, gear down, Config 3, full speed brakes = large rock with airline paint scheme.

Depending on the headwind, this gives close a -9 degree FPA.

When the GS needle comes alive, as you descend into the GS, retract the speed brakes, smoothly pitch up, call for Managed speed, Flaps Full, Landing checklist.

It's hard to be too high using this procedure.

[charliezuluvictor]

Two questions..

In an A320, do the speed brakes get inhibited on selecting the flap lever to full or the flaps actually reaching to the full position ?

After how many seconds does the speed brake memo turn amber and start flashing?

[Ashling]

There is a very usefull procedure for this in the FCTM. Works well.

[Ashling]

And

Speedbrake on finals is not recommended as it is less effective at slow speed, if you use it as you run flap the A/T may target Vapp + 10 and there is a real risk that if you stow it after putting the gear down that you will disarm the ground spoilers. If you should the forget to deploy reverse thrust you will have no spoilers and likely as not be fast greatly increasing your odds of an overrun.

High rates of descent on final in a commercial jet are not ideal especially IMC when it is VITAL to have a floor to prevent terrain encounters. Remember GPWS can be MEL'd

[vilas]

I assure you it is not such a fun if the tail brakes off. There is video by airbus on "use of rudder on jet aeroplane". I would advise you to see that.

[Ashling]

? Who suggested using rudder ?

[Dan Winterland]

The poster who suggested sidelipping.

Speedbrake not authorised in CONF3 in our airline, so CONF FULL is my answer.

[Green Guard]

many good answers, but all of them missing very important point.

When you are too high ( or too close) first thing to do is to LEVELL OFF + speed brake out, to reach gear down speed ( may look opposite to logic to many of us), then as per above...

[thermostat]

Remember too that ground speed and rate of descent are related. The faster the GS the higher the descent rate has to be. Airbus gives 1500 fpm at 140 Kias approach speed. GS 150 use 1600 fpm, GS 160 use 1700 fpm, GS 170 use 1800 fpm and for GS 180 use 1900 fpm. Do NOT exceed 2000 fpm. The above numbers equate to a 6 degree descent angle which is twice that of the glide slope. This technique is technically correct and takes the guess work out of it.
Th.