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787s departing localizer into HKG - below minimum safe alt

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787s departing localizer into HKG - below minimum safe alt

Old 7th Mar 2020, 13:12
  #21 (permalink)  
 
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The attitude stabilising mode is NOT a software bug. It maintains the attitude if there is a loss or interruption of the ILS signal. If this is what is happening in Hong Kong it’s down to an issue with the ILS emitters and not the aircraft.

As far as I know there is no bulletin published currently that would explain this away.
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Old 7th Mar 2020, 13:53
  #22 (permalink)  
 
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Originally Posted by Jumpjim View Post
The attitude stabilising mode is NOT a software bug. It maintains the attitude if there is a loss or interruption of the ILS signal. If this is what is happening in Hong Kong it’s down to an issue with the ILS emitters and not the aircraft.
.
But if this is only happening on the 787 then surely there is an issue, at least in part, with the aircraft?

AFAIK 744s and 777s have been flying that approach for years yet this is the first I’ve heard of this phenomenon happening on a regular basis...


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Old 7th Mar 2020, 14:50
  #23 (permalink)  
 
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The stabilisation mode is present on the 777 as well. Not sure about the -400 but wouldn’t be surprised
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Old 7th Mar 2020, 16:51
  #24 (permalink)  
 
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I’m aware it’s on the T7. Don’t recall it ever being mentioned on the 744 during my time on it...

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Old 7th Mar 2020, 17:01
  #25 (permalink)  
 
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I've read the reports over and over, but struggling to understand what happened.
Did the aircraft deviate from the correct approach course with a centered LOC indication, or was the LOC diamond to the left?
Thx
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Old 7th Mar 2020, 17:15
  #26 (permalink)  
 
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IF YOU DONT READ YOUR AIRCRAFT TECH BULLETINS you may get into TROUBLE.
This issue is mentionned.
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Old 7th Mar 2020, 18:56
  #27 (permalink)  
 
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Originally Posted by de facto View Post
IF YOU DONT READ YOUR AIRCRAFT TECH BULLETINS you may get into TROUBLE.
This issue is mentionned.
Where and in which bulletin? Be specific.

Apart from managing to be extremely patronising, if you’re referring to BAB-61, which I specifically mentioned earlier, then it says the following...

All of the reports Boeing has received regarding this issue have been for unexpected pitch guidance during glideslope capture or tracking. The AFDS manages localizer capture and tracking differently from glideslope capture and tracking. Boeing has not received similar reports of unexpected guidance during localizer capture and tracking.”

So which Bulletin are you referring to?

Last edited by Jumpjim; 7th Mar 2020 at 20:47.
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Old 7th Mar 2020, 21:49
  #28 (permalink)  
 
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Originally Posted by wondering View Post
The mini map below the PFD. Suffice to say Collins ProLine4 and ProLine21 change the indication on the mini map from a pure nav display to an ILS display by using blue needles and changing the sensitivity accordingly. From what heard the Embraer 190 is the same (?) I had a discussion with a former Embraer cpt who wasn´t too impressed by the lack of it on the 787. Imho, it´s easier to spot a deviating needle on the mini map than a 'bug' on the PFD.

Anyhow, back to topic. The attitude stabilizing mode seems to have been a contributing factor. Case of false sense of security?
Originally Posted by wondering View Post
One wonders why the 787 doesn´t have a localizer needle on the PFD like every other aircraft. Only this little bug below the Rad Alt. It´s so easy to miss in a high work load environment.

The AvHerald says the weather was pretty good, so my question is, with 2 x PFD’S, a Standby, 2x Nav displays, PLUS 2x HUD’s showing all the information you could possibly need, was anyone monitoring the flightpath VISUALLY?

The Boeing instructors hammered C H I P s into us.

Cleared for approach

HDG within 40°

ILS tuned

Pointers in correct sense

I know, in IMC you couldn’t look out the window and monitor the path visually, but the 787 has so much information available to the “head up pilot “(PF) to help maintain the correct flightpath in this situation without having to go “head down”.
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Old 8th Mar 2020, 08:16
  #29 (permalink)  
 
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Originally Posted by Jumpjim View Post
Which FCOM bulletin are you referring to?

If you’re referring to BAB-61, that deals with the aircraft entering a stabilisation mode following loss or degradation of the ILS signal. It is not a software bug....
My Company’s version of the FCOM is tailored for my Airline and therefore our FCOM Bulletins will have different numbers (but I assume the dates should be the same).

The FCOM Bulletin you’re referring to regarding the attitude stabilising mode is not the same Bulletin I’m referring to. In my FCOM, the attitude stabilising mode Bulletin is dated 18Oct19 and titled “Erroneous Autopilot Flight Director System (AFDS) Guidance when Instrument Landing System (ILS) Signal Interference occurs”. You are correct this is not a software issue.
The Bulletin I’m referring to is dated 18Dec19 and titled, “Localizer Capture Anomalies.” This is a software issue.
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Old 8th Mar 2020, 09:01
  #30 (permalink)  
 
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Not seen that nor is it a current BAB and we operate -8 and -9 787s. Unless you have an old block point revision I’m surprised. Could you email me a copy? [email protected]
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Old 8th Mar 2020, 11:00
  #31 (permalink)  
 
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This approach is particularly high threat, especially as the 3 degree path intercept is almost co-incident with waypoint RIVER. ATC often vector to space aircraft at exactly 5nm - they don't always get it right. The local guys are aware of this and many of us just go DCT RIVER if it looks like the intercept is going to be close. That's the threat mitigated for most types. Not sure if it's the same with the 787 - but I don't see why not.
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Old 9th Mar 2020, 23:18
  #32 (permalink)  
 
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I'm an airbus guy, so don't know the exact wording for 787 autoflight modes, sorry.

Anyhow, is it SOP on Boeings to go from L/NAV (?) to ILS (?) mode, without using HDG?
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Old 9th Mar 2020, 23:32
  #33 (permalink)  
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Avherald has a copy of the Boeing bulletin here - https://avherald.com/h?article=4d42d0b5&opt=0

Impacting all aircraft, most frequently seen 25R Hong Kong. Reproduced in an engineering simulator and will be fixed in FCM blockpoint 5.1
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Old 10th Mar 2020, 05:41
  #34 (permalink)  
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Originally Posted by b1lanc View Post
Impacting all aircraft, most frequently seen 25R Hong Kong. Reproduced in an engineering simulator and will be fixed in FCM blockpoint 5.1
Most airliners have a Rockwell Collins GLU-920/925 MMR installed as the ILS receiver, some part number differences exist to provide GLS RNP(AR) ADS-B etc.

It is only seems to be one brand of aircraft with one brand of MMR that seems to be impacted, some customers have opted for a different MMR like the Honeywell RMA-55 or the Thales TLS-755.

Others may have a Collins GLU-920/925 installed in a different manufacturers aircraft. They are not impacted.

The issue seems to be with the aircraft manufacturers specific autopilot gains and how it processes the LOC output from the MMR. If the PFD is showing the aircraft passing through the LOC with the LOC captured one has to ask what the autopilot is actually capturing, it is not capturing what is on the PFD.
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Old 10th Mar 2020, 11:25
  #35 (permalink)  
 
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Not the same aeroplane and it’s been a while but in locations where LLZ capture was known to be problematic I would leave LNAV/NAV selected until on or very close to the localiser before selecting APP mode. Worked without fail.
Cheers,
BH.
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Old 10th Mar 2020, 11:41
  #36 (permalink)  
 
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Question

What about TEM ?? MUST be part of APP Briefing i guess >>
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Old 10th Mar 2020, 20:53
  #37 (permalink)  
 
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"Fair Use" for educational purposes. You're not trying to make a buck off of PPRuNe.
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Old 25th Apr 2020, 03:15
  #38 (permalink)  
 
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I guess they haven't been reading this thread.....


2020-04-21

C-FNOH, a Boeing 787-9 operated by Air Canada was conducting flight AC2287 from Vancouver
International Airport (CYVR), BC to Hong Kong International (VHHH), Honk Kong. Approaching
VHHH, the flight crew were cleared to waypoint LOTUS for an ILS approach Runway 25L. When
the aircraft arrived over LOTUS, the flight crew contacted AirTraffic Controller (ATC) and reported
being established on the ILS. ATC advised the flight crew to change to the tower frequency. Just
after, ATC observed the aircraft overshooting the localizer of Runway 25L and descending to 3900
feet above sea level (ASL), which is below the minimum sector altitude of 4300 feet ASL. ATC
provided a terrain warning to the flight crew and the flight crew corrected the flight path to reintercept
the ILS Runway 25L. The aircraft landed at VHHH without further incident.
The flight crew reported receiving a false capture of the ILS Runway 25L and being visual with
terrain and the airport during the event. The operator is conducting an internal assessment in
accordance with their safety management system (SMS).
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