USMCFLYR

The same way that talking about FACTS taken from the CVR and FDR and discussed in the official briefings are considered speculation from some who keep beating the 'wait until the report comes out' mantra.

MaxKts - yes - we are speculate on a daily basis.
People just get extra sensitive to anything called speculation when it involves a mishap and especially if the topic of discussion is pilot error.

ANC - why would you expect fatigue to not be causual? The NTSB seems to find a fatigue issue in about every investigation - Colgan being the continued hot topic and I'll bet you'll see it mentioned in both the Asiana and the UPS mishaps.

FDXLAG

There is conflicting official briefing data and some very confused reporters reporting the data. You got any releases from the NTSb that say official release?

TonyC

That is correct. 7 seconds between "SINK RATE" and sounds of impact.

We do not know the RA height or the sink rate when that alert was sounded.

However, we DO know that, contrary to your earlier assertion, GPWS Mode 1 "SINK RATE" aural alert does not mean the "descent rate would have had to been 2,000+ fpm". That's the only reason I posted earlier, and that's the part of your post I highlighted with bold font. The far end of the graph begins at 1,000 fpm and 30' RA.

At 1,100 fpm, the Mode 1 "SINK RATE" aural alert will sound at 90.5' RA.

At 1,100 fpm, the airplane will descend 128 feet in 7 seconds.

At 1,200 fpm, the Mode 1 "SINK RATE" aural alert will sound at 151' RA, and the airplane will descend 140 feet in 7 seconds.

The accident site terrain was sloped downward away from the direction of travel.

I'm not trying to suggest that I have any idea what altitude the airplane was at, or what its descent rate was. I AM averring that it did not have to be 2,000+ fpm to generate the "SINK RATE" alert.


Here's another interesting fact that you should notice and file away. Before I took a closer look at the graph a couple of months ago, I was under the impression that a "SINK RATE" aural alert would be followed by a "WHOOP-WHOOP, PULL UP" aural warning prior to ground impact. That is not correct. The upper edge of the aural warning graph is not a straight line. At 284' RA and 1,700 fpm, it takes a different slope that ends at 30' RA and 1,500 fpm. Therefore, at sink rates between 1,000 fpm and 1,500 fpm, there will never be a "WHOOP-WHOOP, PULL UP." In that range of sink rates, the next thing you might hear after "SINK RATE", unless you do something to change the path of the airplane, is the sound of ground impact.

Sound familiar?






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USMCFLYR

I haven't seen any of the conflicting official data.
I listened to the NTSB briefings. That is official enough for me.
I'm sure Google/YouTube is your friend too! Heck - I think they even put out info on Twitter -can you imagine that!?!

TonyC

NTSB Member Robert L. Sumwalt's third
media briefing on UPS flight 1354 crash
in Birmingham, Alabama, August 16, 2013





Discussing the Cockpit Voice Recorder:

2:52 - NTSB Member Robert Sumwalt: "16 seconds before the end of the recording was the first of 2 audible warnings, audible alerts that are generated by a computer known as Ground Proximity Warning System. This alert anunciated, 'Sink Rate, Sink Rate.'"


3:22 - NTSB Member Robert Sumwalt: "13 seconds prior to the end of the recording, one crewmember reported to the other that the runway was in sight.


3:36 - NTSB Member Robert Sumwalt: "9 seconds prior to the end of the recording we have sounds that are consistent with impact."


NTSB Member Robert L. Sumwalt's final
media briefing on UPS flight 1354 crash
in Birmingham, Alabama, August 17, 2013



Discussing the Flight Data Recorder:

1:42 - NTSB Member Robert Sumwalt: "The autopilot was engaged until the last second of recorded data."

(Discusssion of the difference between CVR and FDR recorded data. The FDR ended before the CVR, so the "end of recorded data" for each is different.)

2:54 - NTSB Member Robert Sumwalt: "The autothrottle was engaged through the end of recorded data. The recorded airspeed was tracking tracking the autoflight selected airspeed of about 140 knots, which is consistent with the expected approach speed."






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satpak77

what do we think caused this

FDXLAG

That was a lot of work.

So there has been nothing new from the NTSB since Aug 17th. We do have the Wall street journal article that appears to contain new information and this statement:

"The autopilot remained on until the last few seconds before the jet clipped a power line, hit some trees and erupted in a fireball."

MaydayMark

There you go again Tony ... confusing the discussion with FACTS

TonyC

I'm a full-service contributor.


(Wait, somebody's gonna take that wrong. )



I don't believe that's new information -- it simply describes the "sounds that are consistent with impact." We've seen pictures of a clipped power line and trees that were damaged, and, of course, we've been told about a fireball.


What strikes me is the voice 4 seconds prior to impact, "Runway in sight." That sounds like they thought everything was going just fine, looked A-Okay, right up until seconds before it clearly was not.

What I've learned by studying the GPWS Mode 1 graph is that if I ever hear "Sink Rate" a half mile from the runway, it AIN'T just fine, it AIN'T A-Okay. It doesn't matter if I can see the runway at that point. What matters is can I see the ground? So, it doesn't trigger a GPWS escape manuever in our airplane book, but it sure as heck triggers one in MY book from now on.






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satpak77

I hate to speculate but do we have bonafide crew interaction, two-way, prior to impact, or just "remarks" by each other ?