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A321 Flap mis-selection

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A321 Flap mis-selection

Old 28th Jan 2019, 13:54
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A321 Flap mis-selection

A321. Scenario:
-Flap 2/Gear Down.
-A/P, A/T, F/D on
-Localiser established, about to capture Glide
-Flaps 3 called for

Inadvertently colleague selects Flaps 1

What happens?




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Old 28th Jan 2019, 13:59
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I imagine the flaps would go to their commanded position. Is the aircraft above the minimin manoeuvre Flap 1 speed or below it?
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Old 28th Jan 2019, 14:07
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Nothing will happen. F speed is more or less the same as Vls Conf1. If A/THR engaged/speed managed, it will automatically command speed to S speed.
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Old 29th Jan 2019, 00:56
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This actually happened. Speed was around 160kts and thrust suddenly started to gradually increase, as did the speed. The glide had just been captured and I attributed the increase in thrust to the selection of Flap 3 whilst still not fully in a 3 degree profile. When speed increased to about 170 kts, towards 180kts (S Speed), I knew something was wrong and instinctively disconnected A/P and A/T. Simultaneously my colleague noticed his mistake and reselected Flap 3. Throughout these few seconds, i'm pretty sure that Vapp bug was still visible (there was certainly no bug at S Speed), and VLS did not seem to increase, and my intention was to bring the speed back down to Vapp. My question is, had my colleague not noticed his mistake, and I manually brought the speed towards Vapp. whilst Flaps were retracting towards position 1, VLS should simultaneously increase, shouldn't it?
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Old 29th Jan 2019, 09:29
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whilst Flaps were retracting towards position 1, VLS should simultaneously increase, shouldn't it?
Yes - but by less than you think.
If you perform an overweight GA from CONF Flaps 3 to CONF 1+F, the VLS only seems to increase by about 5 kts.
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Old 29th Jan 2019, 10:51
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Does you SOPs not say that PF request Flaps 3 and PM checks that speed is below VFE next, moves the flap handle to Flaps 3 and says “Flaps 3” AFTER they have seen Flaps 3 in BLUE under the flaps display in order to confirm they have selected the correct flap setting ?
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Old 29th Jan 2019, 17:14
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Originally Posted by Black Pudding View Post
Does you SOPs not say that PF request Flaps 3 and PM checks that speed is below VFE next, moves the flap handle to Flaps 3 and says “Flaps 3” AFTER they have seen Flaps 3 in BLUE under the flaps display in order to confirm they have selected the correct flap setting ?
Indeed that is the procedure. Lessons learnt I suppose.
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Old 29th Jan 2019, 17:39
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Originally Posted by Black Pudding View Post
Does you SOPs not say that PF request Flaps 3 and PM checks that speed is below VFE next, moves the flap handle to Flaps 3 and says “Flaps 3” AFTER they have seen Flaps 3 in BLUE under the flaps display in order to confirm they have selected the correct flap setting ?
Of course the SOPs would, but blindly quoting rules at someone who has made a slip is exactly the attitude that stops people filing safety reports because they think they’ll be seen as stupid, as opposed to someone who has made an honest mistake and wants to learn from it...



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Old 29th Jan 2019, 17:47
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Been there - done that. I was 6 months into my career and beginning to feel comfortable... We were in the slot; Descent and approach had gone swimmingly so far, and workload was really rather low.

We were sitting at about 160kts on the glide path with managed speed the target. On F3 selection, the thrust came on as S became the target. With no obvious reason behind it - we were concerned about over speeding Vfe conf 3. My partner intervened by closing the thrust levers and disconnecting ATHR, but by that time the energy was all too much. We went around. When he said “GA - flaps”, I thought it was strange that the flap lever was at 1, and decided i’d best not move it. It did not occur to me, however, that it must have been me that put it there...

Neither of us picked up the error at the time. Downwind, after the subsequent missed approach, we put two and two together. The upshot from the wash up on the ground, and the subsequent phone call from the office, was the same as “effects of controls 2” - that is “Limitation, Opeation, Indication.”

I wont forget that one.
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Old 29th Jan 2019, 18:03
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VariablePitchP

On Airbus, you have no idea what flap setting have been selected by feel of the flap handle alone without checking the blue number or full display. Even when PF and I ask for flaps, I check the blue number or full to make sure my PM has not made an error.





Last edited by Black Pudding; 30th Jan 2019 at 08:26.
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Old 29th Jan 2019, 21:31
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The flap handle is in the wrong place on the Airbus. It is not in the peripheral vision of the pilot flying.

Black Pudding....your company needs to Google "Just Culture".
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Old 29th Jan 2019, 22:17
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Originally Posted by Goldenrivett View Post
Yes - but by less than you think.
If you perform an overweight GA from CONF Flaps 3 to CONF 1+F, the VLS only seems to increase by about 5 kts.
That’s because the defintion of Vls in this case changes from 1.23Vs1g to 1.13 Vs1g.
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Old 29th Jan 2019, 23:04
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That’s because the definition of Vls in this case changes from 1.23Vs1g to 1.13 Vs1g.
I don't think so.
From FCOM DSC-22_10-50-20 Definition of VLS,
"VLS:Lowest Selectable Speed.

Represented by the top of an amber strip along the airspeed scale on the PFD.
Computed by the FAC, based on FMS, and corresponds to 1.13 VS during takeoff, or following a touch and go
Becomes 1.23 VS, after retraction of one step of flaps.
Becomes 1.28 VS, when in clean configuration."

Doesn't mention a GA. Apparently - you need wheels on the ground to trigger 1.13 VS1g logic.
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Old 30th Jan 2019, 08:57
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Many years’ ago I was PM and exactly as the OP scenario, I selected F1 instead of the F3 requested as we were on the ILS into Bodrum.

The A/THR increased thrust - quite a lot - and PF went around. Once gear was up and we were safe, Capt says ‘what happened?’, ‘ Sorry, I cocked up’ says I. ‘OK no problem’ says he, adding with a smile ‘don’t do it again !’

I don’t know why I moved the lever the wrong way - probably tired or distracted; I think cabin secure was very late and I was answering their call - but that is the only time before or since that I ever did that. Point is, we all make mistakes and it is how we manage and catch the mistakes that counts. Capt did exactly the right thing and was decent about my mistake

@ 763 at the risk of opening a big can of worms, the place to see your config in Airbus is on the E/WD config graphic, so the flap lever does not need to be in one’s peripheral vision
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Old 30th Jan 2019, 10:34
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The flap handle is in the wrong place on the Airbus. It is not in the peripheral vision of the pilot flying.
Oh yeah, as opposed to the design that requires PF to take their hand of the thrust levers so that PM can reach awkwardly around the binnacle to get at the flap lever and try to move it accurately to one of about 40 settings. Or does Boeing still work on the assumption that the pilot in the right hand seat never actually flies the aircraft?
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Old 1st Feb 2019, 15:33
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Doesn't mention a GA. Apparently - you need wheels on the ground to trigger 1.13 VS1g logic.
Goldenrivett, No it dosen't. 1.13 or 1.23 has nothing to do with on ground. It is a matter of meeting a minimum go around speed certification requirement while improving go around performance. Below from FCTM:-

If a go-around CONF 1+F is carried out following an approach CONF 3, VLS CONF 1+F may be higher than VLS CONF 3 +5 kt. The recommendation in such a case is to follow SRS orders which will accelerate the aircraft up to the displayed VLS. It should be noted, however, that VLS CONF 1+F equates to 1.23 VS1G whereas the minimum go-around speed required by regulations is 1.13 VS1G. This requirement is always satisfied.

Last edited by vilas; 2nd Feb 2019 at 06:23.
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Old 2nd Feb 2019, 10:16
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Our Company has had several Flap/Gear miselections. The risk is now mitigated by introducing a short pause by the PM between placing his/her hand and the lever and actually moving it. This gives time for both the PM to think what he/she is about to do and the PF to spot the wrong lever is about to be moved. Seems to work nicely.
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Old 3rd Feb 2019, 09:36
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No it dosen't. 1.13 or 1.23 has nothing to do with on ground.
vilas, How does the aircraft know when it is in TOGA from Flight phase 7 (approach - 1.23 VS, after retraction of one step of flaps) or TOGA from phase 8 (Computed by the FAC, based on FMS, and corresponds to 1.13 VS during touch and go)?
If it has nothing to do with on ground logic - then please explain.

Last edited by Goldenrivett; 3rd Feb 2019 at 14:51.
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Old 6th Feb 2019, 13:07
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Golden
The switch from one ratio to another is not always mentioned. Like when you move the flap lever to 1 from zero the VLS changes even with flap slat jammed at zero because the lever position changes the ratio of VLS from 1.28 to 1.23.
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Old 6th Feb 2019, 14:46
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With all automation still in managed the aircraft will command S speed when flap is selected back to flap 1. The real danger is if auto thrust is not engaged and the mis selection is unnoticed. Always a good idea to follow SOP and company procedures to avoid these problems.
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