As I observed on 16 Jan, "No GS".
It's amazing how many crashes have this as a
root cause.
Turkish cargo jet crash kills at least 37 in Kyrgyzstan village
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David MacRay
- Posts: 1259
- Joined: Wed Jun 03, 2015 3:00 pm
Was the plane's equipment u/s or the airport?
I'm pretty sure in the foggy conditions I'd be looking for a new airport without a glide slope indicator but I don't fly IFR, so obviously I don't know what I'm talking about.
Would anyone else go find a runway you can see, instead of looking for that one?
I'm pretty sure in the foggy conditions I'd be looking for a new airport without a glide slope indicator but I don't fly IFR, so obviously I don't know what I'm talking about.
Would anyone else go find a runway you can see, instead of looking for that one?
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ScudRunner-d95
- Posts: 1349
- Joined: Thu Feb 13, 2014 5:08 pm
you got a link to the preliminary report?
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Eric Janson
- Posts: 412
- Joined: Tue Jul 14, 2015 10:31 am
I was looking at the latest update on the [url=http://avherald.com/h?article=4a38d07d&opt=0]AvHerald[/url] website.
It makes no sense why anyone would continue a descent in Cat 2 conditions without capturing the glideslope.
- There are obvious indications on the PFD that the G/S hasn't been captured.
- The moving map display will show the runway [b]behind[/b] you.
- There are a number of auto altitude callouts that remind you that you're getting close to the ground - most companies have 1000' as a height at which the aircraft has to be stabilised on the approach (that includes being on the Glideslope).
All of the above should have triggered a go-around.
I'll wait for the report but it appears a perfectly serviceable aircraft was flown into the ground.
It makes no sense why anyone would continue a descent in Cat 2 conditions without capturing the glideslope.
- There are obvious indications on the PFD that the G/S hasn't been captured.
- The moving map display will show the runway [b]behind[/b] you.
- There are a number of auto altitude callouts that remind you that you're getting close to the ground - most companies have 1000' as a height at which the aircraft has to be stabilised on the approach (that includes being on the Glideslope).
All of the above should have triggered a go-around.
I'll wait for the report but it appears a perfectly serviceable aircraft was flown into the ground.
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Colonel
- Posts: 3450
- Joined: Wed Apr 29, 2015 10:31 am
[quote]It makes no sense why anyone would continue a descent in Cat 2 conditions without capturing the glideslope[/quote]
The high-runner cases:
1) GS indications were wrong (for whatever analog or digital reason), or
2) pilots mis-interpreted indications and thought they had the GS
The high-runner cases:
1) GS indications were wrong (for whatever analog or digital reason), or
2) pilots mis-interpreted indications and thought they had the GS
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Eric Janson
- Posts: 412
- Joined: Tue Jul 14, 2015 10:31 am
[quote author=Colonel Sanders link=topic=5407.msg14603#msg14603 date=1486314599]
[quote]It makes no sense why anyone would continue a descent in Cat 2 conditions without capturing the glideslope[/quote]
The high-runner cases:
1) GS indications were wrong (for whatever analog or digital reason), or
2) pilots mis-interpreted indications and thought they had the GS
[/quote]
Granted I don't fly the 747-400 but I can't see a case for either scenario.
ADS-B data shows the aircraft leveling off then continuing descent. My guess is that the initial approach altitude was set as that is what is normally done.
When the G/S is captured the missed approach altitude is set. This never happened by the looks of things. G/S would continue to show as an 'armed' mode which I believe is a white colour on Boeings. It's blue on airbus.
The most logical way to continue a descent in this situation is to use Vertical Speed Mode and leave the altitude set or set the missed approach altitude if it's higher. If you set a lower altitude then the aircraft will once again level off - the ADS-B data doesn't show this.
Once you descend away from the set altitude is V/S mode the aircraft will continue to descend all the way into the ground if no further action is taken. It's a 'trap' that should be covered in training. The ADS-B data appears to show this.
The report will make for interesting reading.
[quote]It makes no sense why anyone would continue a descent in Cat 2 conditions without capturing the glideslope[/quote]
The high-runner cases:
1) GS indications were wrong (for whatever analog or digital reason), or
2) pilots mis-interpreted indications and thought they had the GS
[/quote]
Granted I don't fly the 747-400 but I can't see a case for either scenario.
ADS-B data shows the aircraft leveling off then continuing descent. My guess is that the initial approach altitude was set as that is what is normally done.
When the G/S is captured the missed approach altitude is set. This never happened by the looks of things. G/S would continue to show as an 'armed' mode which I believe is a white colour on Boeings. It's blue on airbus.
The most logical way to continue a descent in this situation is to use Vertical Speed Mode and leave the altitude set or set the missed approach altitude if it's higher. If you set a lower altitude then the aircraft will once again level off - the ADS-B data doesn't show this.
Once you descend away from the set altitude is V/S mode the aircraft will continue to descend all the way into the ground if no further action is taken. It's a 'trap' that should be covered in training. The ADS-B data appears to show this.
The report will make for interesting reading.
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Eric Janson
- Posts: 412
- Joined: Tue Jul 14, 2015 10:31 am
[quote author=Colonel Sanders link=topic=5407.msg14605#msg14605 date=1486321028]
You really think they were trying to hand-bomb the
GS of a Cat II approach? I have trouble believing
that - unless you're landing on a salt flat many miles
wide, and your touchdown point doesn't really matter.
[/quote]
[b]This is speculation on my part using the ADS-B data.[/b]
The aircraft was above the normal profile and they were busy trying to capture the G/S from above. They had the initial approach altitude set.
They never captured the G/S and the aircraft leveled off at the initial approach altitude.
This may have caused some confusion or been seen late. The most logical next step would be to select a Vertical Speed and continue descent in the hope of capturing the G/S from above. This never happened and the aircraft flew into the ground.
On a personal note I do sometimes have to capture the G/S from above if we are kept high on the approach. There is a procedure in our manuals which calls for setting a higher altitude in the window then selecting a vertical speed of -1500'/min (double the normal rate of descent when on the G/S). This has the effect of increasing your airspeed unless you have the gear down and some flap selected.
You really think they were trying to hand-bomb the
GS of a Cat II approach? I have trouble believing
that - unless you're landing on a salt flat many miles
wide, and your touchdown point doesn't really matter.
[/quote]
[b]This is speculation on my part using the ADS-B data.[/b]
The aircraft was above the normal profile and they were busy trying to capture the G/S from above. They had the initial approach altitude set.
They never captured the G/S and the aircraft leveled off at the initial approach altitude.
This may have caused some confusion or been seen late. The most logical next step would be to select a Vertical Speed and continue descent in the hope of capturing the G/S from above. This never happened and the aircraft flew into the ground.
On a personal note I do sometimes have to capture the G/S from above if we are kept high on the approach. There is a procedure in our manuals which calls for setting a higher altitude in the window then selecting a vertical speed of -1500'/min (double the normal rate of descent when on the G/S). This has the effect of increasing your airspeed unless you have the gear down and some flap selected.
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GRK
- Posts: 7
- Joined: Fri Dec 30, 2016 7:21 am
Capturing the G/S from above on the B744 requires a bit of awareness...namely what your 1000 agl altitude is to start with. To capture from above you have to set 1000 agl in your mode control panel window, make sure both pilots confirm it with each other and the charted value. Then open the vertical speed window and set -1500 fpm (down), the aircraft must be fully configured for landing and all checks complete to satisfy the stabilized approach criteria and if the G/S cannot be captured by that 1000 agl, a Go Around must be carried out. Period. Why these guys got to where they did seems impossible. If they followed the Boeing Flight Crew Training Manual recommended maneuvers and were trained properly the traps should have been mitigated...what a sorry state of affairs if they ignored all the callouts and MCP Mode changes as well as any EGPWS warnings that will be triggered in this case.
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Colonel
- Posts: 3450
- Joined: Wed Apr 29, 2015 10:31 am
Capturing the G/S from above is a bit of an apeshit stunt.
What could go wrong, vectoring hundreds of thousands of
pounds down like that, at low altitude?
Apart from that consideration, you probably won't believe
me, but I've actually captured a "false lobe" above the GS,
when ATC has fucked me around. Descent rate was alarmingly
high.
Not a good place to be. Not sure why someone would
try to push such a bad approach into a landing unless
they were on fire, or had no gas to go around, and were
just trying to pick the best place to crash.
The difference between me and a lot of other guys is
that I have no problem telling ATC, "I'm going around -
if you guys had done it right, we'd only have to do this
once".
I remember one day, flying into North Bay I think, in
the soup, ATC gives me a 100 degree heading change
to intercept the LOC. Really? You get paid how much
to fuck up that badly, and you expect me to pick up
the slack when you do?
What could go wrong, vectoring hundreds of thousands of
pounds down like that, at low altitude?
Apart from that consideration, you probably won't believe
me, but I've actually captured a "false lobe" above the GS,
when ATC has fucked me around. Descent rate was alarmingly
high.
Not a good place to be. Not sure why someone would
try to push such a bad approach into a landing unless
they were on fire, or had no gas to go around, and were
just trying to pick the best place to crash.
The difference between me and a lot of other guys is
that I have no problem telling ATC, "I'm going around -
if you guys had done it right, we'd only have to do this
once".
I remember one day, flying into North Bay I think, in
the soup, ATC gives me a 100 degree heading change
to intercept the LOC. Really? You get paid how much
to fuck up that badly, and you expect me to pick up
the slack when you do?
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