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Airbus aircraft sidestick target on PFD

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Airbus aircraft sidestick target on PFD

Old 26th Jan 2013, 12:23
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Airbus aircraft sidestick target on PFD

How do the pilots use the target cross on the PFD ?
Appears after engine start and disappears after take off.
Im not a pilot and i was wondering how it was used.
Thanks

Thanks for all the replys.

What are we agreeing to as the correct use of the indication?

Last edited by granard; 27th Jan 2013 at 11:01.
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Old 26th Jan 2013, 14:27
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I use it to position the ailerons into wind at rotation on a cross wind takeoff.
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Old 26th Jan 2013, 14:35
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I use it to position the ailerons into wind at rotation on a cross wind takeoff.
Really.....?
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Old 26th Jan 2013, 14:47
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The white Maltese cross and box on the PFD (Primary Flight Display) are used during the flight control check.

The box represents maximum sidestick deflection. During the control check, one pilot will move their sidestick to the limit in all directions in sequence. The other pilot watches this and checks that the correct flight controls, (ailerons, spoilers, elevators and rudder), move the correct amount in the correct direction on the flight control page, which is automatically called when the flying controls are deflected during taxy out.

On take off, the cross and target remain until about 50 or 100' above the ground, (can't remember which), so the Pilot Monitoring can see the control inputs being put in by the Pilot Flying.

{Further to the AF447 crash, I made the suggestion on that thread that during flight this visual be replaced on the PFD's in flashing red if a sidestick was ever held at a limit for more than say 5 seconds, so the other pilot could see what the pilot flying was doing with the sidestick.}
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Old 26th Jan 2013, 15:13
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hetfield,

During takeoffs with very strong crosswinds some aileron may be required to keep the wings level. You don't want to go so far as to deploy the spoilers so the cross can be used to ensure side stick deflection is no more than a third. It's all in the FCTM.
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Old 26th Jan 2013, 17:54
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Don't have any FCOM A320 since 1998.

If AB became wiser and has changed this subject, I apologize my comment.
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Old 26th Jan 2013, 18:43
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Originally Posted by Uplinker
On take off, the cross and target remain until about 50 or 100' above the ground, (can't remember which), so the Pilot Monitoring can see the control inputs being put in by the Pilot Flying.
You apparently don't monitor yourself a lot then ... At 50 the cross has gone for a while already.
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Old 26th Jan 2013, 18:49
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speaking of which: anyone happens to have a reference about what exactly triggers the double crosshair ("sidestick order") to disappear from the PFD after airborne?

I tend to feel that on newer (MSN 4000++) aircraft is disappears somewhat earlier than on the older ones (MSN 1000-) but I could not find an exact reference in the FCOM.

Cheers
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Old 26th Jan 2013, 18:51
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Originally Posted by EGPFlyer
During takeoffs with very strong crosswinds some aileron may be required to keep the wings level. You don't want to go so far as to deploy the spoilers so the cross can be used to ensure side stick deflection is no more than a third. It's all in the FCTM.
It is in my FTCM to avoid deploying spoilers on one side. But it is not specified to use the cross for that matter ... Would you have the precise quote to state so from yours ?
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Old 26th Jan 2013, 18:59
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I heard A rumour that Airbus are looking into ways of making the Airbus more Crosswind friendly. Ie more leigh way with sidestick vs spoiler deflection, Is there any truth in this?
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Old 26th Jan 2013, 19:02
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You apparently don't monitor yourself a lot then ... At 50 the cross has gone for a while already.
Well call me old fashioned, but I am usually more concerned with; positive climb - gear up - monitoring PF's flying - noise abatement turns etc. to notice exactly when it goes.

I will check for you next time I fly.




U
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Old 26th Jan 2013, 20:12
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FCTM
For crosswind takeoffs, routine use of into wind aileron is not necessary. In strong crosswind conditions, small lateral stick input may be used to maintain wings level, if deemed necessary due to into wind wing reaction, but avoid using large deflections, resulting in excessive spoiler deployment which increase the aircraft tendency to turn into the wind (due to high weight on wheels on the spoiler extended side), reduces lift and increases drag. Spoiler deflection becomes significant with more than a third sidestick deflection.
The reference to the cross position is from our company issued training study guide. It states that the limit of sidestick to avoid spoiler deployment is when the edge of the cross is on the central index.
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Old 27th Jan 2013, 01:31
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Hello chaps/chapesses,

In case it's of interest, and at risk of irritating those who have seen it before, I wrote this as part of a post in 1988. It came out of a general discussion on A320 crosswind handling, and was much assisted, IIRC, by Confiture and Lemurian (interesting combination!). Unofficial,of course, and no FCOM or FCTM references, I'm sorry to say:

"CROSSWIND TAKE-OFF
A small amount of into-wind aileron can be selected before starting the T/O run, avoiding "cracking" the spoilers.* During rotation, the upwind wing tends to rise in the conventional manner, and can be countered by retaining into-wind aileron. As the main L/G lifts off, any downwind rudder will be eased off, yawing the aeroplane into wind. This will temporarily assist the aileron. Half a second after lift-off, however, Normal Law in roll is introduced (AND the white cross on the PFDs has disappeared). At that point, any remaining roll input needs to be released.
"5 seconds after main L/G lift-off, Normal Law also becomes fully effective in pitch. Stick-to-elevator control is now removed, and pitch-attitude can be refined by small nudges of sidestick.

" * Roll-spoiler deployment can be avoided by placing the PFD white-cross so that its inner edge is not noticeably to the side of the centre spot."

Now, 5 years later, I realise that I neglected to mention the need for some forward stick on all take-offs, particularly I suppose on a wet crosswind one. This makes it a bit more difficult to judge how much roll (aileron) command you are selecting, and to avoid "cracking" the spoilers. If in doubt, however, you will notice that the F/CTL page appears briefly when you first displace the stick, and enables you (if you are ready for it) to confirm that the spoilers are still stowed. If you miss it, briefly select the page manually.

Regards,
Chris

Last edited by Chris Scott; 27th Jan 2013 at 01:57. Reason: Last paragraph added.
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Old 27th Jan 2013, 02:12
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I agree 100% with Smash Bugger

It's not used for Flight Control checks, the PM looks at the Flight Control page to monitor the controls. The Maltese cross is only for the PM to monitor what the PF is doing on the ground.

Last edited by nitpicker330; 27th Jan 2013 at 02:14.
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Old 27th Jan 2013, 09:45
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As has been discussed ad infinitum on other threads, you cannot always see what input is being made to the opposite sidestick.

If a sidestick had been replaced and wired up backwards (it has happened), then the sidestick might be moved say full left but the controls might go full right. Or a flight computer might have a fault which reverses the sidestick inputs. By crosschecking the maltese cross with the flight control page, I am double checking that the sidestick direction and the flight controls are moving in the same sense.

My original answer to the OP was:
During the control check, one pilot will move their sidestick to the limit in all directions in sequence. The other pilot watches this and checks that the correct flight controls, (ailerons, spoilers, elevators and rudder), move the correct amount in the correct direction on the flight control page,
which seems pretty clear to me?


U

Last edited by Uplinker; 27th Jan 2013 at 09:50.
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Old 27th Jan 2013, 10:00
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Erm, it's just a point, but the side-stick position indicator on the PFD is just that, it's not a target for anything.

And, it's not a Maltese cross anyway; that consists of 4 isosoles triangles joined at the centre; if anything it's a German cross.

so there.
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Old 27th Jan 2013, 10:48
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Thank you SSB for that wonderfully enlightening post. I'm sure we are all much clearer now. Thanks.

I sincerely hope that neither you nor anyone else ever gets a control reversal caused by a faulty sidestick, ELAC, SEC, or PRIM, but with my past knowledge and experience as an electronics engineer, I will continue my double cross-checking.


U
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Old 27th Jan 2013, 11:03
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From my research smashbugger explanation is what I found .
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Old 27th Jan 2013, 11:07
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So you're suggesting that while I Taxy the Aircraft I look down watching the cross on my PFD while the PM also goes heads down watching the Flight Control page to check each surface moves the correct way????????

That sounds like a good way to come to grief.


From the A330 FCTM:---


“Flight Control Check”

PM -Monitor F/CTL page.
PF -Apply full back sidestick followed by full forward sidestick, then release.

PM - "Full up, full down, neutral"

PF -Apply full left sidestick followed by full right sidestick, then release.

PM- "Full left, full right, neutral"

PM -Monitor F/CTL page. Follow through on the rudder pedals to confirm full and correct movement.

PF -Press the PEDAL DISC pb on the steering handwheel, smoothly apply full left and full right rudder and then return the rudder to neutral.

PM -"Full left, full right, neutral"

Ensure that the PM calls are in accordance with flight control inputs

PM Move you own Sidestick as above calling out movements etc.


It's not Rocket Science people.

Last edited by nitpicker330; 27th Jan 2013 at 11:18.
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Old 27th Jan 2013, 11:25
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Strewth, why is this so difficult?

No; the pilot taxying is taxying - eyes out of the cockpit.

Pilot monitoring has eyes inside the cockpit for the control check. PT says 'control check' I look at the GERMAN cross to see what the opposite sidestick is demanding, then I look at the flight control page to see and confirm that the correct flight controls have moved in the correct direction and by the correct amount.

Yes, if PT moved full left and PM saw and called full right, they would both know there was a problem. But what if PT was tired after a long day, and on the 6th sector there were distractions during taxying and did not register that when s/he pulled full left, PM called full right?


U
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