Air India B788 descends to 200 ft over water at HKG
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If the glideslope was unreliable why was it not taken out of service and a NOTAM issued.
Leaving a faulty ILS in service to trap the unwary is dangerous bad practice, someone deserves some serious discipline to be applied.
Leaving a faulty ILS in service to trap the unwary is dangerous bad practice, someone deserves some serious discipline to be applied.
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ATC is normally not monitoring the glide , just azimuth . In addition even if they did , the transponder mode S ALT will need to be detected normally by a rotating SSR antenna, so would take a few seconds to be displayed and another few to transmit the info which would likely be : XXX check or confirm altitude. , GPWS is much faster . It worked well here. Good reaction from the crew, Lesson to be learned ? Oh yes, these cautions warnings on the ATIS to start with More aimed at waiving responsibility from the Airport, authorities than helping the crews. .
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If the glideslope signal is fluctuating it should not be used. ATC should switch it off.
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Oops, do you mean why not fly a RNAV approach?
as far as I know they do not have any RNAV approaches in India, and DGCA probably does not allow their pilots (and aircraft) to fly them (?).
as far as I know they do not have any RNAV approaches in India, and DGCA probably does not allow their pilots (and aircraft) to fly them (?).
Last edited by avionimc; 6th Dec 2018 at 22:44.
Well the autopilot doesn't think it just follows the signal whether it is correct of false... A pilot who has some common sense (and it seems a lot of them don't), who is tracking a G/S with a regular rate of descent on a stable approach will not all of a sudden, if he is competent, simply push the nose hard over to follow a G/S towards the sea especially if he was warned twice by ATC prior to the approach that there might be some problems with the G/S.
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Puzzle me this....
TEM: the threat is the dodgy GS signal, broadcast on ATIS and further backed up by ATC to the crew. How should a crew mitigate this threat to avoid making an error? Fly the LOC only approach (the weather was more than adequate) or if allowed an RNAV approach. It would appear that TEM was not effectively applied by this crew....
TEM: the threat is the dodgy GS signal, broadcast on ATIS and further backed up by ATC to the crew. How should a crew mitigate this threat to avoid making an error? Fly the LOC only approach (the weather was more than adequate) or if allowed an RNAV approach. It would appear that TEM was not effectively applied by this crew....
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Sounds good in theory, but not a lot of time to continually be doing your 318.4 times table down final. Even with the table on the chart, it’s not practical to be continually monitoring it, especially in good weather. Speed, thrust and rate-of-descent (and the view out the window) would be the indicators something was amiss.
Looks like in this case the GS went for a ride and the autopilot obliged. The crew recovered and regrouped.
Reading your post and I'm starting to realize why guys have the speed brakes out diving to 2000' 25 nm from the runway. And yes, after leveling off intercepted a false glide slope and didn't realize it. Where is this DTG function on the FMC? PROG page 1/4.
Here's the really sad part - they were VFR (2214Z) -
VHHH 192230Z 09012KT 9999 FEW022 SCT035 24/19 Q1019 NOSIG=
VHHH 192200Z 09010KT 9999 FEW020 SCT030 24/19 Q1018 NOSIG=
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Does anyone look out of the window ?
If the approach is correct the touchdown point will always be at the same point on the windscreen. If it in the wrong place it is time to worry.
If the approach is correct the touchdown point will always be at the same point on the windscreen. If it in the wrong place it is time to worry.
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There were minimum 2 in the cockpit I assume. .In my (old) days the PF was looking down at the ILS bars,scanning speed/ altitude the PNF was looking outside.and cross checking parameters.
looking at recent accidents and incidents like this one it would seem that many today are all looking at the bars and nobody is scanning the other parameters.or bother to look outside before minimum even when VMC.
Is is how the new training is made?. Full trust on automation ?
looking at recent accidents and incidents like this one it would seem that many today are all looking at the bars and nobody is scanning the other parameters.or bother to look outside before minimum even when VMC.
Is is how the new training is made?. Full trust on automation ?
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A fluctuating signal can bring the aircraft into a bad situation really fast. I’m sorry, but I’m one of those lazy pilots who tend to be a bit relaxed when I fly. I don’t sit there and read out mile vs altitude every single mile when I do an ILS.
A sudden GS pitch down on short approach followed by GPWS and go around. Good call.
The GS should not have been on the air.
A sudden GS pitch down on short approach followed by GPWS and go around. Good call.
The GS should not have been on the air.
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I suppose if one was determined to do the ILS but not wanting the aircraft to be following any fluctuations(happens in Seattle as well), they could just use the V/S function while following the glideslope in general. Especially with the weather conditions being beautiful VMC, they could just be mostly visual. Back it all up by confirming 1600 feet when passing VH721, continuing at about 7-800 fpm, checking distance to go versus altitude continues to make sense along with the sight picture out the window.
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punkaolouver finally nailed it.
This is exactly what we do as regular operators into HKG on 07R. Happens frequently. We always shoot the ILS, aware of the possibility of GS fluctuation. The RNAV is available, but we only bother if it's low cloud or vis. If the GS plays up (about 1 in 10 times), just select VS 7-800 fpm or disconnect and hand fly. Easy peasy.
However, this is common sense, experience and airmanship we're talking about here... Sadly not something prevalent in many operators in this neck of the woods, especially the airline were discussing or the muppets to the north of us.
This is exactly what we do as regular operators into HKG on 07R. Happens frequently. We always shoot the ILS, aware of the possibility of GS fluctuation. The RNAV is available, but we only bother if it's low cloud or vis. If the GS plays up (about 1 in 10 times), just select VS 7-800 fpm or disconnect and hand fly. Easy peasy.
However, this is common sense, experience and airmanship we're talking about here... Sadly not something prevalent in many operators in this neck of the woods, especially the airline were discussing or the muppets to the north of us.
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couple of months ago, was also established on the ILS 7R, autopilot engaged, stable and all of the sudden aircraft pitched down very rapidly and violently.....immediately disconnected ap, recycled FDs, and able to salvage approach.
Yes they offered Rnav on the Atis but company not authorized for Rnav, and believe Atis said possible GS oscillations- thought they meant it might scallop a little up and down, really wasn't expecting that.
Yes they offered Rnav on the Atis but company not authorized for Rnav, and believe Atis said possible GS oscillations- thought they meant it might scallop a little up and down, really wasn't expecting that.
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punkaolouver finally nailed it.
This is exactly what we do as regular operators into HKG on 07R. Happens frequently. We always shoot the ILS, aware of the possibility of GS fluctuation. The RNAV is available, but we only bother if it's low cloud or vis. If the GS plays up (about 1 in 10 times), just select VS 7-800 fpm or disconnect and hand fly. Easy peasy.
However, this is common sense, experience and airmanship we're talking about here... Sadly not something prevalent in many operators in this neck of the woods, especially the airline were discussing or the muppets to the north of us.
This is exactly what we do as regular operators into HKG on 07R. Happens frequently. We always shoot the ILS, aware of the possibility of GS fluctuation. The RNAV is available, but we only bother if it's low cloud or vis. If the GS plays up (about 1 in 10 times), just select VS 7-800 fpm or disconnect and hand fly. Easy peasy.
However, this is common sense, experience and airmanship we're talking about here... Sadly not something prevalent in many operators in this neck of the woods, especially the airline were discussing or the muppets to the north of us.
I find it hard to accept that this is an ongoing problem, and that nothing has been done about it. A glideslope that has been known to bring aircraft into upsets should never be on the air. NOTAM or no NOTAM.