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-   -   A380 low at Melbourne (https://www.pprune.org/rumours-news/582101-a380-low-melbourne.html)

framer 29th Jul 2016 07:55


It has been known for decades that the approach phase is perhaps the most critical phase and during which most errors occur and incidents result;
I'm in furious agreement with you Rat5 about all your comments on flying the plane and knowing what your profile is/ should be ( a basic 3x profile isn't that hard even if the airfield is above sea level) but I think it is worth pointing out that the above sentence is only half right.
The approach and landing phase is the most critical as you said, but more errors are made in the pre-departure phase of flight. I think that is something worth knowing and thinking about when I see people rushing like mad to claw back 5 minutes.
Cheers

RAT 5 29th Jul 2016 11:11

Agree about the errors: I defer to your statistics.

Tee Emm 30th Jul 2016 12:32


If it doesn't settle down you need to reduce the automation and, in the worst case, fly the plane. http://cdn.pprune.org/images/smilies/eek.gif

So you "reduce" the automation and see if that works. How long do you wait for reduced automation to give the desired result before gasp horror you actually are forced to fly the plane. I suggest that instead of "reducing" automation if it doesn't settle down, it would be prudent to disengage the automation immediately and seamlessly fly the plane where you want it to go. Of course if the pilot lacks the manual flying skills to do so, then simply reduce the automation as you say and send out a PAN before resorting to manual flying.:E

Airbubba 30th Jul 2016 21:52


Originally Posted by Tee Emm (Post 9456471)
So you "reduce" the automation and see if that works. How long do you wait for reduced automation to give the desired result before gasp horror you actually are forced to fly the plane. I suggest that instead of "reducing" automation if it doesn't settle down, it would be prudent to disengage the automation immediately and seamlessly fly the plane where you want it to go.

This reducing the level of automation is the modern training speak for what you are saying, i.e. turn the magic off and make the plane do what you want it to. :ok:

The FAA and Boeing talk about 'levels' of automation from one to four. I think Airbus talks about similar levels with less automation being more 'direct'.

As Airbus says in their SOP treatise on 'Optimum Use of Automation':


At any time, if the aircraft does not follow the desired flight path and/or airspeed, do not hesitate to revert to a more direct level of automation, i.e.:

Revert from FMS-managed modes to selected modes; or,

Disconnect AP and follow FD guidance (if correct); or,

Disengage FD, select FPV (as available) and hand fly the aircraft, using raw data or visually (if in VMC); and/or,

Disengage the A/THR and control the thrust manually.
http://www.airbus.com/fileadmin/medi..._SOP_SEQ02.pdf

As usual, a lot of this philosophical stuff about levels of automation finds its way into the company pubs as CYA boilerplate paragraphs and filters down to the line through the training department.

On the particular KIX approach I was discussing earlier, you could go into a heading and vertical speed or altitude hold mode and let the plane settle down as it made the turn to intercept the ILS and then reselect LNAV/VNAV (on a Boeing) and then go to approach mode when the signal was stable.

You certainly could turn the autopilot off and hand fly the approach but recently that is somewhat frowned upon where I work since you had briefed a coupled approach.

Even following the glide path down with vertical speed if it doesn't capture for some reason is now considered a deviation from your planned procedure. I'm told that you should go missed, request holding, reassess your nav status, call the company and speak to a subject matter expert if required and rebrief the approach with reduced nav automation capability. You've got plenty of gas, right? ;)

aterpster 31st Jul 2016 12:15

If, in fact, the flight was cleared for an RNP AR approach, not only is that an instrument approach, it requires specific training and flight crew operating procedures. The database isn't supposed to be messed with. Performance-based navigation actually means what it says with RNP AR IAPs. Deviation from the VNAV path, exceeding maximum segment speed, or deviating from the lateral path all invalidate the approach.

White Knight 31st Jul 2016 13:06

And these RNP approaches are NOT flown in APP mode, but rather in NAV/DES so should follow the vertical constraint...

I have personally however had a colleague try and stuff up the approach to 34 in MEL with finger trouble and only intervention from my side stopped us going below a waypoint altitude constraint...

Easy to have finger trouble on such a tiring pattern that we fly here!

aterpster 31st Jul 2016 14:23

1 Attachment(s)
Attached is the Austrian AIP chart for the RNAV-P (RNP) RWY 34 approach. If entering at either LAVER or GOOLA the specified speed (or less) and RF legs must be followed. The vertical profile (VNAV or VPATH) must entered not less than 2,000. 3,000 or higher must be maintain untl ML632 or ML642. ATC cannot intervene on either of these transitions other than to assign a speed less than the maximum specified. ATC can vector to an extension of the final approach course, in which case the approach must begin not later than MEXUN. In the case of a vector to the final outside of MEXUN the last assigned altitude should be maintained until intercepting the VPATH, but descending to 2,000 after SUDOS to intercept the VPATH at 2,000 would be acceptable with ATC concurrence.

Oz also provides an OEI procedure with their RNP AR approaches. Page 2 would apply only in that case and only with a declaration of the engine failure.

haughtney1 31st Jul 2016 14:57

As a general comment regarding RNP approaches in MEL, I've found over the years that it all goes well, until ATC decide to vector you off, or worse keep you high and then expect you to be back on profile and speed etc.
I even asked the ATCO why clear us for the approach and then vector us off..etc his reply "because that's what we do"
As I said, just a general comment, but it does add complexity to an approach that is further complicated by various operator restrictions and physical limitations.

oscar zoroaster 31st Jul 2016 15:15

Automation and competency in general.
 
At what point does the reliance on, and extended use of, automation create a critical dysfunction in the thought processes and mechanics of flying?
And at what stage of training (prior non-automation flight experience) does that impact occur?
As an example, at some point (already in testing), there will be automobiles with with autopilot modes which can be engaged and/or disengaged. Theoretically, the disengagement mode would be activated for problem situations to allow the human with driving experience to control the situation. That would be appropriate for a skilled driver. At some point however, there will be "drivers" of automobiles who have essentially been passengers for a decade and will be highly unskilled for actually driving even in basic control situations (breaking distance calculations, turning at speed, etc.) let alone high traffic situations and poor road conditions such as ice, rain, snow.

aterpster 31st Jul 2016 16:28

huatney1:


As a general comment regarding RNP approaches in MEL, I've found over the years that it all goes well, until ATC decide to vector you off, or worse keep you high and then expect you to be back on profile and speed etc.
I even asked the ATCO why clear us for the approach and then vector us off..etc his reply "because that's what we do"
As I said, just a general comment, but it does add complexity to an approach that is further complicated by various operator restrictions and physical limitations.
The second time they did that, I would refuse the RNP AR approach.

Chris2303 31st Jul 2016 17:15

Does the approach need to be redesigned?

aterpster 31st Jul 2016 17:44

Chris2303:

Does the approach need to be redesigned?
The approach is fine. It should have been designed with air traffic management in mind. If not, then the Oz aviation authority issued incorrect specs to the procedures designers. I doubt that was the case. Sounds like an ATC facility problem to me.

Airbubba 31st Jul 2016 18:30


Originally Posted by aterpster (Post 9457396)
ATC can vector to an extension of the final approach course, in which case the approach must begin not later than MEXUN.

From your chart it looks to me like the approach could begin inside MEXUN as long at it was not later than ML627 which is the FAF. Not a huge difference but I've received these direct to FAF RNAV-P clearances in Europe before. And sometimes I've gotten vectors that seem to closely mimic the published side approach transitions.

From ATSB website these guys were 15 nm south though and perhaps vectored for the long final.

aterpster 31st Jul 2016 21:12

airbubba:

Check the note referenced with "#." Jepp makes it clearer; the note appear alongside MEXUM.

Airbubba 31st Jul 2016 22:27


Originally Posted by aterpster (Post 9457687)
airbubba:

Check the note referenced with "#." Jepp makes it clearer; the note appear alongside MEXUM.

Thanks! :ok: I'm not used to that chart format, hopefully I wouldn't have missed it but I certainly might have. :eek:


Originally Posted by Willie Nelson (Post 9455280)
As the facts in this case are yet to be revealed I cannot comment specifically on what happened to the A380 however, what I can say regarding any type of GNSS approach (RNAV-Z or RNP-AR) is that you must not arm the approach pushbutton unless the ATC assigned altitude and the IAF (or suitable Direct to waypoint) altitude are the same, otherwise the FMGC switches from NAV to FINAL APP mode and therefore will drop down to the NEXT altitude constraint as per the FMGC constraints, thereby bypassing the relevant safe altitude even if it is still selected in the FCU.

This was why, some time back Airservices changed the terminology to "when established cleared Runway xx x approach" that is to say:established on the approach itself and not simply tracking to intercept a waypoint on the approach.

One possible way down the primrose path would be if they had one of the approach transitions from the side loaded, got vectors to a long final instead and saw that they could go to MEXUN without reselecting the approach since it was already in the box and the rest of the approach is the same for all the transitions. Unfortunately, the 3000 feet restriction at SUDOS would not be seen by the FMGC.

It will be interesting to see whether they were cleared for the approach out over the water and selected approach mode too soon with a missing waypoint constraint.

Rule3 1st Aug 2016 06:19

Re post27 by aterpster.

"Austrian AIP" Mate, there are no Kangaroos in Austria.;)

aterpster 1st Aug 2016 08:46

Rule3:

Re post27 by aterpster.

"Austrian AIP" Mate, there are no Kangaroos in Austria.
I caught one of those, obviously missed that one. In any case the chart I posted should make the location obvious. :)

aterpster 1st Aug 2016 12:08

1 Attachment(s)
Aibubba:


Thanks! I'm not used to that chart format, hopefully I wouldn't have missed it but I certainly might have.
Attached are the Jepp charts for the procedure in question. However, Emirates was likely using Lido charts.

aterpster 1st Aug 2016 12:29

1 Attachment(s)
LIDO chart:

Airbubba 1st Aug 2016 13:45

Thanks again for the charts. :ok:


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