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

slast 26th Jul 2016 13:22

A380 low at Melbourne
 
From FlightGlobal

The Australian Transport Safety Bureau is investigating an incident where an Emirates Airline Airbus A380 descended below minimum assigned altitude while on approach to land at Melbourne Tullamarine International airport.

The Bureau’s safety investigations and reports website says that the aircraft, registered A6-EDM (MSN 42), was operating a flight from Auckland on 14 July when the incident occurred. It was positioned around 28km south of the airport at the time.

“When cleared for the runway 34 RNP approach, the aircraft descended below its assigned altitude of A030 and out of controlled airspace. The controller alerted the crew and the aircraft climbed back to A030,” it says.

The operational incident is being investigated, with an expected completion of July 2017.
What would the bottom of the controlled airspace here?

eckhard 26th Jul 2016 13:49

Melbourne CTA C3 lower limit is 2500ft.

The RNAV Z for 34 has a platform altitude of 3000ft.

The RNAV P (AR) for 34 has a platform of 2000ft but that is only applicable within about 8nm from the THR.

Sector Safe is 3700ft.

Airbubba 26th Jul 2016 14:44

From context it looks like 'A030' is 3000 feet MSL. Is that an FMS format or something?

In recent years we've had a rash of incidents where the arrival was 'cleaned up in the box' and altitude constraints were inadvertently deleted from the vertical navigation path. And, as Captain VanderBurgh observed two decades ago, we have become 'children of the magenta line' even on visual approaches.


The operational incident is being investigated, with an expected completion of July 2017.
Good thing it's nothing important, so no hurry, right?

BuzzBox 27th Jul 2016 01:58


The operational incident is being investigated, with an expected completion of July 2017.

Good thing it's nothing important, so no hurry, right?
That's fast for the ATSB. In some cases we're still awaiting reports on serious incidents that occurred over three years ago!

Capn Bloggs 27th Jul 2016 04:42


From context it looks like 'A030' is 3000 feet MSL. Is that an FMS format or something?
"Altitude 3000". As opposed to F350, being "Flight Level 350".

Standard ICAO format...same as you put in the Flight Notification.

Airbubba 27th Jul 2016 05:16


Originally Posted by Capn Bloggs (Post 9453236)
Standard ICAO format...same as you put in the Flight Notification.

Thanks, is a Flight Notification some sort of flight plan in Oz perhaps? Or an ATC message?

Capn Bloggs 27th Jul 2016 05:31

ICAO Flight Notification... every IFR aeroplane flies on one. You might call it the Operational Flight Plan (at least the bit that actually tells ATC what you're doing)?

Airbubba 27th Jul 2016 06:17


Originally Posted by Capn Bloggs (Post 9453245)
You night call it the Operational Flight Plan (at least the bit that actually tells ATC what you're doing)?

That's it, thanks again. :ok: Just as you will never see 3000 MSL written as A030 in an NTSB report, I've never heard the ICAO flight plan called a Flight Notification.

Fortunately, as an American, I don't worry about that ICAO stuff too much when flying internationally. ;)

I was in KIX a while back and saw a purple trimotor freighter drop down quite low over the bay turning final on that curved ILS to 24L. They then started a climb and I thought they would go missed but they continued to an uneventful landing. I assume it was a case of 'extend me off the runway' (or whatever the equivalent phrase is on the Mad Dog) and a low phony vertical profile was generated and perhaps chased in vertical speed away from the altitude window.

Offchocks 28th Jul 2016 08:42


Does anyone have any idea what he is talking about?
KIX is Kansai airport in Japan, purple trimotor freighter is probably a FedEx MD11, anything else?

pattern_is_full 28th Jul 2016 08:48

Kansai International... FedEx MD-11, a.k.a. Mad Dog.... flying published curved step-down approach to stay over water and avoid overflying populated land, involving both a VOR and an NDB, to intercept the ILS at the marker.

http://opennav.com/pdf/RJBB/JP-AD-2....RJBB-en-JP.pdf

Presumably, swapping NAV sources lost the altitude settings, although I have no idea about MD autopilot logic, either.

(The approach is sort of an all-radio version of the old "billboard ILS" at Kai Tak/Hong Kong.)

Anyway - back to previously scheduled programming....

Basil 28th Jul 2016 10:01


In recent years we've had a rash of incidents where the arrival was 'cleaned up in the box' and altitude constraints were inadvertently deleted from the vertical navigation path.
So, if pilots can work that out, why don't our flight ops departments insist that positive action has to be taken to delete an altitude restriction otherwise it remains in place even when cleaning up?
Otherwise the tool (FMS) is damaging the workpiece (V-Nav).

Tee Emm 28th Jul 2016 11:09

During simulator training generally would it be correct to say manually flown visual approaches are rarely practiced. Thus the accent is on following the magenta line via the FD?

Offchocks 28th Jul 2016 12:50


During simulator training generally would it be correct to say manually flown visual approaches are rarely practiced.
Before I retired a couple of years ago, most sim sessions had a segment where you had to demonstrate a manual visual approach without any glide slope guidance, meaning no ILS, vasi/papi or vnav indication.

filejw 28th Jul 2016 13:09


Originally Posted by Airbubba (Post 9453268)
That's it, thanks again. :ok: Just as you will never see 3000 MSL written as A030 in an NTSB report, I've never heard the ICAO flight plan called a Flight Notification.

Fortunately, as an American, I don't worry about that ICAO stuff too much when flying internationally. ;)

I was in KIX a while back and saw a purple trimotor freighter drop down quite low over the bay turning final on that curved ILS to 24L. They then started a climb and I thought they would go missed but they continued to an uneventful landing. I assume it was a case of 'extend me off the runway' (or whatever the equivalent phrase is on the Mad Dog) and a low phony vertical profile was generated and perhaps chased in vertical speed away from the altitude window.

Ref Airbubbba comment on KIX ILS 24L and FedEx. I most likely caused by hitting app arm to early. The arrival transition calls for LNAV/VNAV in most a/c and if you select APP to early the aircraft will start looking for LOC/GS . Iv seen this happen in more than one type over the years.

jackharr 28th Jul 2016 16:15

On my final simulator session before retirement 18 years ago, the examiner suggested I might like to fly visually under the Dartford Bridge. That was more difficult than might be imagined but I did succeed. I wanted to follow up with a go through the Dartford Tunnel but it was pointed out that the sim might take a while to reset:)

Jack

Airbubba 28th Jul 2016 17:21


Originally Posted by filejw (Post 9454678)
Ref Airbubbba comment on KIX ILS 24L and FedEx. I most likely caused by hitting app arm to early. The arrival transition calls for LNAV/VNAV in most a/c and if you select APP to early the aircraft will start looking for LOC/GS . Iv seen this happen in more than one type over the years.

That would be my suspicion as well. And maybe they went back out of approach mode when it started to chase, hurriedly tried to reselect things in the box and dropped some constraints.

On the vertical profile you have that mandatory 2600 ft. crossing just as you start the turn to intercept final. I've shot that approach with and without GPS over the years and sometimes the plane does the intercept gracefully but other times it starts to hunt as you turn toward KN. If it doesn't settle down you need to reduce the automation and, in the worst case, fly the plane. :eek:

Perhaps the incident I saw had the ILS extended off the FAF and inadvertently deleted the (at or above) 2000 ft. and 1600 ft. altitude constraints. Maybe they went to 1200 ft. way too soon, caught the mistake and climbed back up on profile.


Originally Posted by Basil (Post 9454506)
So, if pilots can work that out, why don't our flight ops departments insist that positive action has to be taken to delete an altitude restriction otherwise it remains in place even when cleaning up?
Otherwise the tool (FMS) is damaging the workpiece (V-Nav).

That's one of the reasons I was hoping we would soon find out more about the A380 incident at MEL.

They were 15 miles from the runway. Looks like a 3000 ft. crossing restriction at SUDOS and 2000 ft. at ML627. If they were still on vectors maybe a misread of the altitude clearance, serious at any altitude but potentially deadly down low.

Or, were they given direct to SUDOS and cleared for the approach and somehow started down early on some faulty vertical guidance? Did they sequence the waypoints to go to ML627 and thought they could descend to 2000 ft.?

Maybe we will know in a year or so.

In this golden era of the FMS there seem to be subtle traps on waypoints and constraints that differ on each aircraft I've flown. On some planes if you get a vector to final you need to do an intercept to a waypoint ahead or it will not become 'active'. On others it doesn't matter and you can concentrate on flying the approach.

I've certainly armed approach mode too soon. And too late. And this RNP stuff is all automatic until it messes up. :D


Originally Posted by Derfred (Post 9454404)
Does anyone have any idea what he is talking about?

My apologies, I let myself lapse into pilot jargon and perhaps used some terms unfamiliar to you. I wasn't familiar with a Flight Notification and certainly have learned from this discussion myself. :ok:

RAT 5 28th Jul 2016 19:27

I've read all the 'maybe's & perhaps' and what the automatics might have been doing, or not. No-one has mentioned the weather. IF they were in VMC why were they not looking out the window? If they saw the a/c starting its descent too early; if they wondered why they were 3000'/2000' at 15nm; if they were slightly curious about "what's it doing now?" why did they allow it to continue? Even if they were IMC the parameters seem to suggest something was not kosher. To hell with selecting this & that at the wrong time was the cause of an early descent. Sorry, but 'mind the office.' Or am I being too simple & harsh? A good dinner and even better bottle of red makes me cranky; so my wife tells me.

Before I retired a couple of years ago, most sim sessions had a segment where you had to demonstrate a manual visual approach without any glide slope guidance, meaning no ILS, vasi/papi or vnav indication.

Wish it were common all over; but then that topic has been beaten to death numerous times. Let's not reopen it. Lucky you had an enlightened training dept. Sadly, I'm associated with an outfit who prides itself on in-depth training but has reduced the amount of manual flying in the sim. There are the enlightened ones and there are the others. Nowt so curious as folk and none so blind as they who do not see.

Willie Nelson 29th Jul 2016 03:27

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.

In simple terms, selecting APP mode early on the FCU has the same effect as (spuriously) being in LOC capture but you're only tracking to the IAF and not yet runway aligned, therefore you might get G/S capture on base for example.

In FINAL APP mode the aircraft likes the track so it descends, it's not smart enough to see that a direct to is not necessarily on the approach itself.

If the A380 did what I'm referring to (yet to be determined) then it's not the first time it's occurred on YMML 34.

glofish 29th Jul 2016 06:22


To hell with selecting this & that at the wrong time was the clue of an early descent. Sorry, but 'mind the office.' Or am I being too simple & harsh?
No RAT 5, you are spot on. It is a disgrace that after DME has been invented and now GPS is on every cheap smartphone, professional pilots still go below a 3deg path within 10nm of the runway with heavies. There is no reason to do so, distance to go is omnipresent in all airliners, so there is only inherent danger.

Those who continue do it, do it so without being aware and should be removed from such cockpits asap.

RAT 5 29th Jul 2016 07:06

Willie: That is an informed explanation for a non-AB pilot. You may be correct, BUT.......
what would any pilot do, in any a/c, if it captured a false ILS Glide Slope and started descending. I hope there would be an instant disconnect and level off until the a/c was re-positioned to capture the correct GS. Whether a full GA would be necessary would depend on circumstances. A false GS was not uncommon at some airfields. The solution at every airfield was to have a gross error check ticking away in your mind. When it happened you were aware and knew what to do about it. On later versions of some a/c it became impossible to capture GP before LLZ. This helped the dummies who were asleep.
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; thus one would hope crews are at their most alert. After hours of safe sky underneath you most of it s now above you. Senses should be heightened.
If there is a known gotcha in the automatic system then surely the manufacturer should be taking steps to design it out AND publishing alerts to the crews. SOP's could be another level of avoidance. If Willie is correct this is a case in point; as too was the Korean B777 gotcha in San F.
Every a/c is trying to bite you in the backside. Don't let it.


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