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Air Niugini plane misses runway, lands in sea off Micronesia island

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  • Evan
    replied
    Originally posted by Gabriel View Post
    Interesting. And it seems to match what was recorded in this accident.
    So the 737's TAWS doesn't match the TSO?

    Do you have that doc in the la link? I would like t see the rest of it.
    And where does it come from? Boeing? An airline? PDMG? And for what version of the 737 is it? (the header just says 737)
    It's from a Boeing FCOM for the B737 -600, -700, -800, -900.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post
    FCOM

    [ATTACH=CONFIG]26789[/ATTACH]
    Interesting. And it seems to match what was recorded in this accident.
    So the 737's TAWS doesn't match the TSO?

    Do you have that doc in the la link? I would like t see the rest of it.
    And where does it come from? Boeing? An airline? PDMG? And for what version of the 737 is it? (the header just says 737)

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel
    May I ask where did you get that from? The only spec that I know is the TSO in the link posted by flashcrash, and a red "PULL UP" text warning seems to be incompatible with a caution (execssive) "SINK RATE" aural alert. Rather, the red "PULL UP" text warning is compatible with the aural warning "PULL UP" associated with severe sink rate.

    Ground Proximity Envelope 1, 2 or 3, Excessive Descent Rate, Class A & Class B
    FCOM

    Click image for larger version

Name:	pullup.jpg
Views:	1
Size:	487.5 KB
ID:	1041232

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post
    PULL UP is displayed whenever the SINK RATE warning is active.

    SINK RATE PULL UP is triggered by severe (rather than excessive) descent rate. The descent rate was not severe enough to trigger this warning.
    May I ask where did you get that from? The only spec that I know is the TSO in the link posted by flashcrash, and a red "PULL UP" text warning seems to be incompatible with a caution (execssive) "SINK RATE" aural alert. Rather, the red "PULL UP" text warning is compatible with the aural warning "PULL UP" associated with severe sink rate.

    • Ground Proximity Envelope 1, 2 or 3, Excessive Descent Rate, Class A & Class B
      • Caution
        • Visual Alert: Amber text message that is obvious, concise, and must be consistent with the Aural message.
        • Aural Alert:Sink Rate

      • Warning
        • Visual Alert: Red text message that is obvious, concise and must be consistent with the Aural message.
        • Aural Alert:Pull-Up

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post
    PULL UP is displayed whenever the SINK RATE warning is active.

    SINK RATE PULL UP is triggered by severe (rather than excessive) descent rate. The descent rate was not severe enough to trigger this warning.
    May I ask where did you get that from? The only spec that I know is the TSO in the link posted by flashcrash, and a red "PULL UP" text warning seems to be incompatible with a caution (execssive) "SINK RATE" aural alert. Rather, the red "PULL UP" text warning is compatible with the aural warning "PULL UP" associated with severe sink rate.

    Ground Proximity Envelope 1, 2 or 3, Excessive Descent Rate, Class A & Class B

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    The other question is why there wasn't a pull-up call if pull-up was displayed in red on the PFD.
    PULL UP is displayed whenever the SINK RATE warning is active.

    SINK RATE PULL UP is triggered by severe (rather than excessive) descent rate. The descent rate was not severe enough to trigger this warning.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    Altitude callouts are not mandatory and are configurable by the airlines. I don't know what was the altitude callout schedule that this airline was using.
    I'm thinking these annunciations were deactivated. Otherwise, I can't make sense of it.

    Leave a comment:


  • BoeingBobby
    replied
    Originally posted by ATLcrew View Post
    They're sparring about who can do this aviationing blabber gooder.
    Ya think?

    Leave a comment:


  • Gabriel
    replied
    Originally posted by flashcrash View Post
    Table 4-2 confirms the accuracy of the table reproduced in the report. But to my untrained eye it does seem a little confusing, since the SINK-RATE PULL UP call-out is assigned a higher priority than an ALTITUDE call-out. Admittedly this isn't the same thing as a GLIDESLOPE call out though.
    It is not the same thing than the SINK-RATE call-out either.

    You have Sink rate Pull up in #2, Altitude call-out in #14, Sink Rate in #17 and Glide slope in #19.

    The priority makes sense to me. Any call including the words "pull up"should have priority over almost anything (except a stall warning and a reactive windshear warning where you have to look very closely at the speed and pulling up can be a problem).

    If you receive a pull up call, you should initiate an aggressive evasive maneuver to get all the climb you can from the airplane, so the altitude is not so important (you are going to climb as much as you can anyway).

    The altitude calls are a snapshot. It tells you that you are crossing a milestone. There is only one chance to get an altitude call. If it is missed because of a higher priority call, it can't be triggered later when you are not at that altitude anymore. So if you missed, you lost that part of input for situational awareness for good.

    The sink rate and glideslope calls are advisory caution messages and reflect a status. You normally don't receive a single glideslope or sink rate call because it takes some time bring the glide slope back to center or to reduce the sink rate. You may miss one instance of these calls to give room for an altitude call, but it is very likely that you will hav gotten or will have other such calls immediately before or after the altitude call, so situational awareness is not impacted. And in the unlikely event that the deviation from the glideslope or the exceedance of the sink rate is so short lived that you miss the only such call due to an altitude call, basally who cares. It was already corrected by when the altitude call is over, otherwise you would receive more instances of the call.

    There was only 1 altitude callout since the GPWS warnings started, the "100" call.
    Altitude callouts are not mandatory and are configurable by the airlines. I don't know what was the altitude callout schedule that this airline was using.

    The other question is why there wasn't a pull-up call if pull-up was displayed in red on the PFD.

    Leave a comment:


  • flashcrash
    replied
    Originally posted by Evan View Post
    Have a look at appendix H on the report. It appears that altitude callouts should have priority over SINK RATE and GLIDESLOPE
    Interesting! I searched for the original document on the FAA website and found it here:

    http://rgl.faa.gov/Regulatory_and_Gu...FILE/C151b.pdf

    Table 4-2 confirms the accuracy of the table reproduced in the report. But to my untrained eye it does seem a little confusing, since the SINK-RATE PULL UP call-out is assigned a higher priority than an ALTITUDE call-out. Admittedly this isn't the same thing as a GLIDESLOPE call out though.

    Do we know for certain there was no ALTITUDE callout before the aircraft hit the water?

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    That said, even if it would not have helped in this specific case, I do wonder, if the system detects a situation that warrants a pull up alert, then why doesn't the aural warning says "woop woop, pull up!" instead of saying "glideslope" and sending a "pull up" SMS to the PFD.
    Have a look at appendix H on the report. It appears that altitude callouts should have priority over SINK RATE and GLIDESLOPE, but that isn't what happened here.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by flashcrash View Post
    It is. I thought the wording of the NTSB comment was eloquent. And if I'm characterizing your previous posts and Evan's correctly, I think it goes to the heart of what you were both saying:

    "NTSB staff believes the disregard of the alerts, disregard of the PFD display guidance, and the continuation of an unstable approach demonstrate that any additional guidance, alert, or warning would be similarly disregarded by the flight crew and ineffective in preventing the accident."
    That said, even if it would not have helped in this specific case, I do wonder, if the system detects a situation that warrants a pull up alert, then why doesn't the aural warning says "woop woop, pull up!" instead of saying "glideslope" and sending a "pull up" SMS to the PFD.

    Leave a comment:


  • flashcrash
    replied
    Originally posted by Gabriel View Post
    Is that what you are talking about?
    It is. I thought the wording of the NTSB comment was eloquent. And if I'm characterizing your previous posts and Evan's correctly, I think it goes to the heart of what you were both saying:

    "NTSB staff believes the disregard of the alerts, disregard of the PFD display guidance, and the continuation of an unstable approach demonstrate that any additional guidance, alert, or warning would be similarly disregarded by the flight crew and ineffective in preventing the accident."

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    The PFD showed a red text "PULL UP" warning. The investigators concluded that if the pull up warning had been aural, this would likely called the attention of the crew who then would have executed a go around. The NTSB disagreed, saying after all the indications and warnings (including aural warnings) that the crew disregarded, there is no reason to think that they would not have disregarded this additional one too.

    Is that what you are talking about?
    Agreed. This was not loss of situational awareness, as the report suggests. This was loss of positional awareness. The were well aware of the situation.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by flashcrash View Post
    Seems NTSB has filed a dissent against the PNG report. Not against the causal factors but against the report's recommendations. My apologies if you guys were already aware.
    The PFD showed a red text "PULL UP" warning. The investigators concluded that if the pull up warning had been aural, this would likely called the attention of the crew who then would have executed a go around. The NTSB disagreed, saying after all the indications and warnings (including aural warnings) that the crew disregarded, there is no reason to think that they would not have disregarded this additional one too.

    Is that what you are talking about?

    Leave a comment:

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