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Coupled to the ILS in good weather. Should ATC be advised?

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Coupled to the ILS in good weather. Should ATC be advised?

Old 27th Jul 2017, 13:38
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Coupled to the ILS in good weather. Should ATC be advised?

https://www.atsb.gov.au/media/577324...-023-final.pdf

Interesting ATSB report about ILS signals interference.
One paragraph in particular caught my eye.

It said: Aeronautical Information Publication. If a pilot advises air traffic control that an ‘autoland’ or ‘coupled approach’ is to be flown, then air traffic control will either report ‘ILS critical area not protected’ or ‘LVP11 in force’ if the critical area is protected.

It is probably a good bet that the majority of approaches in good weather to ILS equipped Australian runways by domestic and international airliners are auto-coupled, although not necessarily to an auto-land. This could be company policy where maximum use of the autopilot is encouraged or even required. It could also be if an overseas crew will auto-couple because that is their company policy everywhere. Some Domestic crews may prefer to stick with the automatics to 1000 feet AGL or even below because they cannot be bothered to stretch the friendship and fly by hand. Maybe it a pilot confidence issue.

Are Australian crewed aircraft required to advise ATC if the approach is to be auto-coupled in good weather or otherwise, even though the intention is not an auto-land? It seems that way, judging by the wording of the AIP. Or do crews ignore the risk of signal interference from aircraft taxiing or holding in the critical area while flying the coupled approach.
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Old 27th Jul 2017, 14:14
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How does this apply then at Sydney? When they're on IVAs both aircraft are tracking on the localizer even when its CAVOK and the sensitive area is never protected. I've heard in the past guys request an autoland and approach have said 'you can do the autoland if you like but you'll be cleared for the IVA'. My answer would be no, but happy to be proven wrong
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Old 27th Jul 2017, 17:57
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There is also the opposite outcome, pitch up events due to false glideslope lobes, although this is a beast is a rarer as you have to be quite high to suffer its effect. The Dutch safety board did a great writeup after a stickshaker event:Pitch-up Upsets due to ILS False Glide Slope as wel las responses from different regulatory authorities. The report is available on that home page.



Someone even did a Safety Management System failure analysis on how this issue was missed for so long: Safety Management: Reversing the False Glide Slope Myth .
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Old 27th Jul 2017, 19:41
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Flying into LaGuardia runway 04, if you fly coupled to the ILS on a good weather day, then the false courses due to departing traffic on 13 or aircraft in the critical area will put you either;
A) into the side of a building in manhattan, or;
B) into JFK airspace

Most of the time in the US you are hand flying un-coupled (with the ILS info there as backup) when visual conditions permit as appropriate.
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Old 27th Jul 2017, 21:43
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There is a very good example demonstrated by a SQ B777 in Munich November 2011. 'Google' it and see what happens.
If the aircraft needed an auto land for CAT3 validity (every 28 days with my previous company) I would advise ATC. More importantly with no LVP in place, be extra alert in case it goes into 'Ex-wife mode'.
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Old 28th Jul 2017, 00:26
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Often happens in SYD when flying coupled ILS and an A380/B744 gets towed across the far end ofthe runway. LLZ signals bounce around.

No one warns you.

And no one HAs to.

But it would be nice to know before the aircraft starts skewing around and you have to disconnect.
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Old 28th Jul 2017, 01:38
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Bring on GLS everywhere
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Old 28th Jul 2017, 03:38
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Often happens in SYD when flying coupled ILS and an A380/B744 gets towed across the far end ofthe runway. LLZ signals bounce around.

No one warns you.

And no one HAs to.

But it would be nice to know before the aircraft starts skewing around and you have to disconnect.
+1 - I have experienced this on a few occasions at SYD.
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Old 28th Jul 2017, 10:53
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Are Australian crewed aircraft required to advise ATC if the approach is to be auto-coupled in good weather or otherwise, even though the intention is not an auto-land?
No.

It seems that way, judging by the wording of the AIP.
No. The AIP merely explains the response that will be provided by ATC if so advised.

Or do crews ignore the risk of signal interference from aircraft taxiing or holding in the critical area while flying the coupled approach.
No. Crews are aware of the risks of signal interference.

This incident would very likely have happened even with LVP in force. The ILS critical area is only protected inside 4NM. This aircraft was at least 10NM when it intercepted a bad G/S signal.

The crew picked it up, the aircraft picked it up (G/S flags), and ATC picked it up.

The system worked.

Having said that, there are other defences that crew can utilise to further protect approach integrity (such as situational awareness, height-distance awareness, not arming G/S until on LOC and satisfied with the signal, VNAV path backup, VSD if installed, RAD ALT awareness, avoiding "dive and drive" techniques in favour of continuous descent, etc).

But clogging up the frequency with redundant "autocoupled" calls ain't one of them.
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Old 29th Jul 2017, 07:17
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Folks,
You could always try that rather rather old fashioned idea: "Fly the Aeroplane".
The aeronautical version of "double click".
Tootle pip!!
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Old 29th Jul 2017, 09:09
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I experienced the aircraft getting towed across the LLZ beam several times in Sydney. Always when it was 8/8th's CAVOK, so I just did what Leadsled suggested above, I disconnected the autopilot and actually flew the aircraft for once

morno
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Old 29th Jul 2017, 13:33
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Often happens in SYD when flying coupled ILS and an A380/B744 gets towed across the far end ofthe runway. LLZ signals bounce around.

No one warns you.

And no one HAs to.

But it would be nice to know before the aircraft starts skewing around and you have to disconnect.
Yep +2

Have had this also happen in SYD, but was the G/S. Aircraft was auto-coupled on a VMC day and started rapidly pitching up towards 10 nose up at a great rate of knots. I saw the G/S pitch up suddenly and the A/P just went for it. The autothrottle couldn't keep up and the airspeed was washing off fairly quickly.
I chickened out and disconnected when the nose hit 5 degrees nose up.

Another crew had it too only they got a airspeed low GPWS alert this time as they were a tad late with the thrust correction but recovered none the same.

And they want to replace us with pilotless pax carrying aircraft.....
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Old 29th Jul 2017, 22:13
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Does AIC H20/17 address these hazards?
http://www.airservicesaustralia.com/...up/a17-h20.pdf
1.1 Disturbance of ILS GP and LOC signals at YSSY when certain aircraft types
are taxiing has resulted in unstable approaches, resequencing and additional
arrival delays.
1.2 This AIC draws attention to these specific vulnerabilities to assist in threat
identification.
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Old 30th Jul 2017, 00:14
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Originally Posted by Gate 15L
a airspeed low GPWS alert
Thread drift but... please explain?
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Old 30th Jul 2017, 08:00
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Airspeed Low Alert

On airplanes with Airspeed Low aural, an alert "AIRSPEED LOW, AIRSPEED LOW" provides the flight crew with low airspeed awareness. The aural annunciates when the current airspeed decreases into the minimum maneuver speed amber bar.

The aural coincides with the low airspeed alert on the airspeed indication.

B737-NG FCOM VOL 2 15.20.23
I believe its a optional extra on the EGPWS... this is on the NG...
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Old 30th Jul 2017, 08:32
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Thanks Gate 15L. Impressive!
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Old 30th Jul 2017, 09:45
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The Airspeed Low Aural was introduced to the NG by Boeing after the Turkish Airlines incident in Schipol were it stalled coupled up to an ILS approach.
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