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A320 Engine-Out Acceleration

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Old 24th Apr 2010, 06:19
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A320 Engine-Out Acceleration

Everyone I've talked to agrees that flap retraction during acceleration after a go-around with an engine failure should be directly from flap 3 to flap 1 when reaching F Speed, but my question is, where is this procedure written?

Only place I found where they mention that you should go from Flap 3 directly to Flap 1 is if you do a go-around in over-weight.

According to FCTM flap retraction should be made in normal order, F3, F2, F1...

Does anyone know?
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Old 24th Apr 2010, 07:04
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Flap 3 to 1 is correct if you have flown a flap full approach. If you have flown a flap 3 approach you would have selected flap 2 on initiation of the go around (up 1 stage).

It is written in my copy of the FCTM on page AO-020 14/16 (OEI Go Around) where it refers you to pages AO-020 7 - 10/16 (ENGINE FAILURE AFTER V1). You will see it on the diagram on page 10.

However, you do have to think a bit. There may be a speed restriction in the GA procedure involving turns below S speed to avoid terrain in which case it would be appropriate to select flap 2 until after the speed restriction.

HTH,
WS
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Old 24th Apr 2010, 07:43
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flap retraction should be made in normal order, F3, F2, F1...
you never do flap rectraction like this. not on the goaround and not even if you do a takeoff with CONF 3. you select CONF 1 next during acceleration at ACC ALT.

...OVERWEIGHT LANDING (only)......if landing configuration is different from FLAP FULL, use 1+F for goaround....(QRH).

Last edited by Airbus_a321; 24th Apr 2010 at 07:57.
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Old 24th Apr 2010, 07:43
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Hi founder,
interesting thread ... as you said FCTM's procedure is to RETRACT FLAPS ONE STEP:

ONE ENGINE INOPERATIVE GO-AROUND
A one engine inoperative go-around is similar to that flown with all engines operating. On the application of TOGA, rudder must be applied promptly to compensate for the asymmetric increase in thrust and to keep the b target centred. Smoothly increase pitch to follow the SRS. If SRS is not available, the initial target pitch attitude is 12.5°. As a one engine inoperative approach is flown with Flaps 3, the initial flap retraction is to Flaps 2. With a positive ROC and an increasing RA, retract the gear. The lateral FD mode is initially GA TRK, which guides the aircraft on the track at TOGA selection. If there are terrain considerations on the go-around path or specific tracking requirements, select NAV without delay. Select ALT at the engine inoperative acceleration altitude and retract the flap using the same technique as described in the Engine Failure after V1. At certain weights and CG positions, it may not be possible to satisfy b target demands at VLS. Consequently, when obstacle clearance is assured, accelerate to a speed at which the b target can be satisifed.

Sincerely don't think a "direct" CONF1 selection (from CONF3) would be safe for a one engine inoperative go-around, cause of the sudden lift loss combined to a relatively low thrust; instead it would only be detrimental on a/c performances. Here's my reasoning:


- Unpredicted wind-shears
- High airport altitude
- Low pressure
- High OAT
- High weight ...



are all factors that negatively affects wing lift or just need more thrust to be produced, so max care should be taken; a gain on acceleration following a "direct" flaps retraction on an initial G/A attitude of 12° is negatively counterbalanced by the high loss in wing lift, thus no need to hurry on cleaning the bird up ...



Cheers,
fredgrav
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Old 24th Apr 2010, 07:57
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Sincerely don't think a direct CONF1 selection (from CONF3) would be safe for a one engine inoperative go-around,
Except - QRH 2.25 Overweight Landing:
"...If the aircraft weight is above the maximum for go around (from the table below) use Flap 3 for Landing.
In all cases - if Landing config is different from Flap Full use 1+ F for Go Around"
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Old 24th Apr 2010, 08:05
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Except - QRH 2.25 Overweight Landing
yep sure
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Old 24th Apr 2010, 09:41
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Sincerely don't think a "direct" CONF1 selection (from CONF3) would be safe for a one engine inoperative go-around, cause of the sudden lift loss combined to a relatively low thrust; instead it would only be detrimental on a/c performances. Here's my reasoning:



- Unpredicted wind-shears

- High airport altitude
- Low pressure
- High OAT
- High weight ...
It's perfectly safe and it is the normal technique used in the simulator for LST and LPC. Bear in mind that the acceleration is done level, not climbing (Push to Level Off - V/S 0). The likely exception, as I wrote above, is for close-in turns in the EOSID or GA procedure with an associated speed restriction when it might be appropriate to select flap 2 due to the increase of indicated A-prot speed in manoeuvres.

Windshear CONDITIONS are hardly unpredicted (Cb, frontal passage) and if that were the case, the advice is to fly a flap 3 approach so the go-around would be initially in flap 2.

High altitude, low pressure, high temperature and high AUW are all taken care of by the landing performance calculation and provided the aircraft is below the calculated maximum weight and can make the necessary Missed Approach Climb Gradient there is ample performance on one engine in TOGA power. Generally speaking in Europe there is no GA weight limit and a 320 can make 5%+ gradient. In the Middle East in summer it may well be different.

HTH
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Old 24th Apr 2010, 09:48
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Fredgrav,

Just out of curiosity, have you actually ever flown a A320 or any aircraft for that matter?
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Old 24th Apr 2010, 10:59
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According to my FCTM (2009) on page AO-020 P10 you have the part about acceleration after engine failure after V1.

"At the engine-out acceleration altitude, push ALT to level off and allow the speed to increase. If the aircraft is being flown manually, the PF should remember that, as airspeed increases, the rudder input needed to keep the beta target centred will reduce. Retract the flaps as normal. When the flap lever is at zero, the beta target reverts to the normal sideslip indication."


Note the "Retract the flaps as normal". What does this mean?

Well according to QRH procedure for "normal retraction" this would mean F2, F1, F0...

I still want a text written by airbus in the FCOM's where it sais that in any go-around you should go from F3 directly to F1... I dont see this yet...
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Old 24th Apr 2010, 11:32
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"Go around flaps"
(retract one step)


FCOM 3.03.23 p2
and 4.05.80 p5:

at acceleration altitude
- retract flaps on schedule


the schedule is not specified, so it can only be the same as the take off case, which for eng out is specified in FCOM 3.02.10 p4 and is the same as in normal take off, that is: at F speed, flaps 1, S speed flaps cero.

Any different procedure should be specified. If nothing is said, then flaps have to be retracted normally, or else you are inventing new procedures of your own.

Also take a look at the definition of F speed at FCOM 3.04.10 p2, if you still have any doubts.
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Old 24th Apr 2010, 14:26
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Just to clarify: The retract one step applies to the initiation of the go-around. That is when TOGA is selected and the aircraft rotated to 12.5 or 15 degrees. Therefore, on a flap full approach the flaps will be selected to 3 when the PF initiates go-around; on a flap 3 approach the flaps will be selected to flap 2 on the initiation of the go-around.

Founder,

I think you must have a copy of the FCTM which is out of date; my (company specific) electronic FCTM is dated Jan 2010. There should be a diagram of the procedure on page 10 which clearly shows the the flaps should be retracted from 3 > 1 in the acceleration phase. The actual procedure is published in the SOPs which are company specific and not necessarily included in the (electronic) FCOM.

Take it from me (11 years/7000hrs all 320 variants and TRI/TRE) that flaps 1>3 is correct.
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Old 25th Apr 2010, 14:18
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I've recently taken to reading about the Airbus philosophy of the A320, very interesting & very complex to a novice:-) Fascinating stuff though
I have another question here that's a little off the current subject but still in the G-around phase so rather than start a whole new thread I thought I'd tack it on here:-)
I have read that ...........during a go-round & moving the thrust lever/s to TOGA when the flap is NOT at "0" position will select the SRS...........fair enough but what about a flapless App then a go-round it reads to me as though the SRS is then not available to the pilot?

Just curious so perhaps someone here who has a few hrs under their A320 belts can shed a little light on the above

Cheers

Wmk2
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Old 25th Apr 2010, 16:52
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Wally,

For the A330/A340 the note below applies. QRH covers this scenario.

SRS activation is linked to the FLAP LEVER POSITION and not the Flap position.
Hence the situation you are describing, namely a 0FLAP + 0 SLAT approach is flown with the FLAP LEVER selected to F! in order to give SRS for any go-around.


For the A320 OFLAP approaches flown with Flap 3 lever position selected.

Last edited by Meikleour; 25th Apr 2010 at 17:07.
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Old 25th Apr 2010, 18:13
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It's perfectly safe and it is the normal technique used in the simulator for LST and LPC. Bear in mind that the acceleration is done level, not climbing (Push to Level Off - V/S 0). The likely exception, as I wrote above, is for close-in turns in the EOSID or GA procedure with an associated speed restriction when it might be appropriate to select flap 2 due to the increase of indicated A-prot speed in manoeuvres.


Hi wingswinger,
here's, as depicted by Airbus, the One Engine-out Takeoff Path (assuming the "critical" engine fails at Vef), where the acceleration is done level; though it is not the One Engine-out Landing Climb/Go-around path.

As a one engine inoperative approach is flown with Flaps 3, the initial flap retraction is to Flaps 2
RETRACT FLAPS ONE STEP
At this point, the "ON SCHEDULE" as well as the 2 previous quotes, make me think that retraction has to be carried out sequencially, as for every normal go-around. As I said, that's my belief, and can be either right or wrong.
A reference beyond FCOM's and FCTM's could be the Airbus briefing note "Getting to grips with aircraft performance":
http://pilotlab.net/aircraft-manufac...erformance.pdf

If possible, could you post a reference where it is written that "retraction goes directly from CONF 3 to 1" and this is "the normal technique used in the SIM" ? ...

Many Thanks,
fredgrav
____________________________________________________________ _

Fredgrav, Just out of curiosity, have you actually ever flown a A320 or any aircraft for that matter?
Hi Oneoutsider,
most of the people who designed the bus, didn't even fly it.
I'm 22, haven't flown the bus yet, though I've been studying it since 2006. My knowledge is purely theoretical, and it's hard at times to figure out how things really are; nevertheless, as we're all discussing theory in here, every post should have references to official documents not to personal experience ...

Best,
fredgrav

Last edited by fredgrav; 25th Apr 2010 at 21:03.
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Old 25th Apr 2010, 20:58
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Guys ... you have to apply the KISS here.

Try reading FCOM3 - In flight performance - go around (3.05.35 p5 in my book)

You have tables for Go around - flaps 3 and flaps 2 but NO table for flaps 1, wonder why
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Old 25th Apr 2010, 21:25
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Dkz You are totally right. Hey Rocca how are you up there??'
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Old 25th Apr 2010, 21:39
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To Founder

Wingswinger gave you correct and accurate answers.

But after reading your original question, I'd just would like to draw your attention on the following:

Differentiate:

- retracting flaps at the initiation of the go-around is one thing and can be done from F3 to F1 in some particular cases.

- retracting flaps (cleaning the A/C) at acceleration altitude/third segment (that's for Fredgrav who loves theory ) is always from F3 to F1 (if you reached your altitude with F3). That's the normal Airbus flaps retraction schedule.

You have tables for Go around - flaps 3 and flaps 2 but NO table for flaps 1, wonder why
Because A320 is not certified to fly CONF2 in final approach configuration. It's either CONF3 or CONF Full for landing (so CONF 2 or CONF 3 for go-around...).

Last edited by shortfuel; 25th Apr 2010 at 22:15.
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Old 25th Apr 2010, 21:51
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@ fredgrav

If possible, could you post a reference where it is written that "retraction goes directly from CONF 3 to 1"
From FCTM Normal operations Page 7.

"During takeoff phase, F and S speeds are the minimum speeds for retracting the surfaces: • At F speed, the aircraft accelerating (positive speed trend): retract to 1. • At S speed, the aircraft accelerating (positive speed trend): retract to 0."
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Old 25th Apr 2010, 21:57
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Hi shortfuel,
where can I find a EO profile for the "second type" of G/A (retracting flaps cleaning the A/C at acceleration altitude...) ?

Thanks !
fredgrav
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Thanks Rudder !
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Old 25th Apr 2010, 22:19
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what "second type"? I don't get it.
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