Thai Air B777 Melbourne NDB approach
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Bluetoo,
The basic point is, under V-Nav and L-Nav, should you rely on waypoint altitude protection or should the MCP Alt window reflect the minimum altitude that you can descend at you present position?
Forget the Daros 1A, have a look at the Melbourne plate (URL link), should the MCP Alt have been set to the locator height or to 4000 (until 12D)?
Which is the safe option, and which is SOP?
Airmanship suggests 4000' is safe, SOP's (in my airline) suggest the locator height.
The basic point is, under V-Nav and L-Nav, should you rely on waypoint altitude protection or should the MCP Alt window reflect the minimum altitude that you can descend at you present position?
Forget the Daros 1A, have a look at the Melbourne plate (URL link), should the MCP Alt have been set to the locator height or to 4000 (until 12D)?
Which is the safe option, and which is SOP?
Airmanship suggests 4000' is safe, SOP's (in my airline) suggest the locator height.
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Must be some confusion here - my apologies - thought you were talking about the STAR and direct tracking on the STAR- not the Approach itself. Approach constraint would be different entirely, and I agree the in the Melbourne case 4000' is the minimum until BOL ( I am using the jepp chart).
Our SOP, once "established", is to set the MDA. Then allow either the VNAV or use VS/FPA to follow the briefed or charted profile down. We don't wind in each limiting step because it increases workload to the point of distracting the crew, especially where there are many steps.
Re setting limiting steps on a STAR, if you did do this, then you couldn't set your actual level cleared-to by ATC. This would lead to the possibility of missing your assigned (as opposed to STAR-limit) level.
Re setting limiting steps on a STAR, if you did do this, then you couldn't set your actual level cleared-to by ATC. This would lead to the possibility of missing your assigned (as opposed to STAR-limit) level.
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Our SOP, once "established", is to set the MDA. Then allow either the VNAV or use VS/FPA to follow the briefed or charted profile down. We don't wind in each limiting step because it increases workload to the point of distracting the crew, especially where there are many steps.
Many new crew use the automation so much they can't see the forest for the trees and, if crew can't keep a mental picture of what they are doing, they don't belong in the pointy end in the first place.
Are NDB approaches 'interesting', in some circumstances, especially with a large heavy jet?
Of course they are, but that is precisely why we are paid the big bucks.
Can't stand the heat, stay out of the kitchen.
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Xsbank, have you had a look at the profile on the full report?
One thing notorious for RWY16 is the undulating terrain associated with steep gullies around the 6-4nm final. This may set off an alert if not in the appropriate config. A few years ago I have had a terrain alert on a clear day with a slighly higher descent than normal with flaps 1 (airbus) selected.
One thing notorious for RWY16 is the undulating terrain associated with steep gullies around the 6-4nm final. This may set off an alert if not in the appropriate config. A few years ago I have had a terrain alert on a clear day with a slighly higher descent than normal with flaps 1 (airbus) selected.
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Sure, the outcome was a non-event but history is rife with RT misheard followed by CFIT. Here is one example:
http://aviation-safety.net/database/...?id=19890219-0
In this ymml case, overhearing the cloud level elsewhere was 1700 when in fact it was 1000 @ymml. Presumably @1700 the crew must have wondered when they would break out.
I think the EGPWS was a tidge late wrt the initial deviation from the minimums but a timeline would help. Certainly the corrective action upon the second warning was welcome.
I would count this as an EGPWS 'save'. A valuable piece of equipment to say the least.
http://aviation-safety.net/database/...?id=19890219-0
In this ymml case, overhearing the cloud level elsewhere was 1700 when in fact it was 1000 @ymml. Presumably @1700 the crew must have wondered when they would break out.
I think the EGPWS was a tidge late wrt the initial deviation from the minimums but a timeline would help. Certainly the corrective action upon the second warning was welcome.
I would count this as an EGPWS 'save'. A valuable piece of equipment to say the least.
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This incident has nothing to do with a vnav approach. The crew flew over the ndb, set the minima and then pushed LVL CHG or, for the Airbus minded, the equivalent of selecting open descent. A basic error but not a non-event. Certainly airline procedures will need to be addressed as the crew response to an EGPWS warning at night would probably not be considered ideal.
A jet decending below MDA is a non-event?
They didn't just get below profile they busted an MDA step. I also gather they were in cloud. It's an NDB approach, but it's a straight in runway aligned one with no reversal procedure. Coupled to LNAV it's basically a localiser approch from an altitude management point of view.
Also, why not use a FPA descent? at the top of the profile (11.5DME) set -3.0 degrees dialing in check heights along the way and let Mr. Boeing do the rest.
They didn't just get below profile they busted an MDA step. I also gather they were in cloud. It's an NDB approach, but it's a straight in runway aligned one with no reversal procedure. Coupled to LNAV it's basically a localiser approch from an altitude management point of view.
Also, why not use a FPA descent? at the top of the profile (11.5DME) set -3.0 degrees dialing in check heights along the way and let Mr. Boeing do the rest.
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They didn't start descending at the appropriate point, the FO hit Level Change to get down, and it certainly looks like they had briefed for a VNAV approach because of the 50' addition to MDA. Anyway, at 6,8 D they were a 1000' low on profile triggering GPWS. NDB or not....totally irrelevant, the point is the crew started descending in a non-standard mode and did nothing when passing through the VNAV path/CDA profile.
On a side-note, the crew responded correctly to the GPWS. Levelling and continuing visually is accceptable on GPWS caution.
On a side-note, the crew responded correctly to the GPWS. Levelling and continuing visually is accceptable on GPWS caution.
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"On a side-note, the crew responded correctly to the GPWS. Levelling and continuing visually is accceptable on GPWS caution. "
I think this is acceptable in day VMC but this occurred at night time. Also there is a high probability that the crew's SA was not good. The only reason to ignore an EGPWS warning is if you are aware of the terrain and you can see it. I don't think that was the case in this incident.
I think this is acceptable in day VMC but this occurred at night time. Also there is a high probability that the crew's SA was not good. The only reason to ignore an EGPWS warning is if you are aware of the terrain and you can see it. I don't think that was the case in this incident.
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b777 ndb app at melbourne
my goodness still doin an ndb app. my question is why do we not get rid of the whole ndb app. i mean i can see if its used as an aid to other apps but to have an entire app solely based on ndbs?man its out of date and out of taste
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How can anyone cock up a twin locator or ndb approach?
Especially into 16 at Mel which is as simple as they come!
Strewth!...didn't we all learn this in a link trainer when we were kids?
Gotta wonder about the standards here, guys!!
Especially into 16 at Mel which is as simple as they come!
Strewth!...didn't we all learn this in a link trainer when we were kids?
Gotta wonder about the standards here, guys!!
How utterly disgraceful!
How utterly third world!
How utterly primitive!
Why in the name of the heavens is any international airline aircraft required to carry out an NDB approach into any civilised International Airport?
For God's sake, aren't the passengers taxed enough on their tickets and the airlines on landing charges to expect 21st friggin' century technology approaches at destination?
Even your piece of crap shopping trolley car has a reliable GPS these days...
Shame Australia! Shame and again Shame!
I am embarrassed to be Australian. Does anybody remember that Australia was involved with the invention of the Microwave Landing System for example?
I've seen much better service as most of the poor third-world destinations in Asia.
I say shoot the bastards collecting the money at Melbourne Airport for their miserable failure and incompetence in maintaining a safe aviation facility at a minimum acceptable standard that might be expected by a reasonable man for the operation of International RPT!
How utterly third world!
How utterly primitive!
Why in the name of the heavens is any international airline aircraft required to carry out an NDB approach into any civilised International Airport?
For God's sake, aren't the passengers taxed enough on their tickets and the airlines on landing charges to expect 21st friggin' century technology approaches at destination?
Even your piece of crap shopping trolley car has a reliable GPS these days...
Shame Australia! Shame and again Shame!
I am embarrassed to be Australian. Does anybody remember that Australia was involved with the invention of the Microwave Landing System for example?
I've seen much better service as most of the poor third-world destinations in Asia.
I say shoot the bastards collecting the money at Melbourne Airport for their miserable failure and incompetence in maintaining a safe aviation facility at a minimum acceptable standard that might be expected by a reasonable man for the operation of International RPT!
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There is no way this particular twin locator will be removed. Qantas Longhaul is obsessed with twin locator approaches and no doubt will pay for this one to remain in service.
Oh wait a minute - I hear the quote - "its not qantas - its the casa matrix!"
(Which is in laymans terms "I am to lazy to change it - or spend money and install new technology and equipment into our ageing fleets")
Oh wait a minute - I hear the quote - "its not qantas - its the casa matrix!"
(Which is in laymans terms "I am to lazy to change it - or spend money and install new technology and equipment into our ageing fleets")
