ATSB report: QF002 electrical malfunction (Jan 2 2008)

[Markus Vitzethum]

Today an interesting report on an occurrence with 747-400 VH-OJM, operating as Qantas Two on Jan 2nd 2008 has been released by the ATSB.

http://www.atsb.gov.au/media/2216537/ao2008003.pdf

It gives some interesting reading on the problems which arose after water from an overflowing (due to ice) drain line flooded the galley and leaked into the main equipment bay. Three Generator Control Units were affected from the water and shut down, leaving the flight crew with AC busses 1,2 and 3 failed and, apparently, vital instruments only powered from the battery. After landing (edit: and taxi to gate), they had only 9 minutes of battery life remaining.

While I'm still studying the report, I am surprised to read that due to GCUs 1,2,3 failed, the respective BTBs are also gone and hence, AC bus 4 is not able to power the failed AC busses 1-3...  :shock:

Markus

[John Golin]

Standby for more media bashing of Qantas...

[John H Watson]

After landing (edit: and taxi to gate), they had only 9 minutes of battery life remaining.

Routine tests of 744 batteries on the test bench involve the discharging of the battery at a rate higher than Standby Power usage and they normally exceed 60 minutes.

Don't believe everything you read in official reports  

It's interesting to note that the DC Isolation Relays were closed. Usually the BTBs and DC Isolation Relays open at the same time. These DC Isolation Relays need power to keep them open. Perhaps there was no power.

[Mariano]

Markus,

Thanks for the interesting link and very nice to hear from you again! I looked for you a few times on cyberspace to no avail.

Glad to see you are back in the PS1/PSX community. Your past contributions have done a lot (and still do) for PS1.

Mariano

[Phil Bunch]

As best I can figure, they've moved the above PDF report.  I downloaded successfully soon after it was posted in this forum but it wouldn't download when I tried about a day later on my iPad.

Here's new links.  I don't know if the report is the same - perhaps someone accidentally posted the wrong report draft or perhaps they are simply reorganizing their web pages.

http://atsb.gov.au/publications/investigation_reports/2008/aair/ao-2008-003.aspx   Photos at this page, etc, as well as links to the PDF report.  Also, links to both the preliminary and the final reports are on this page, towards the upper right of the page.

Link to final report, as of 12:37PM, New York time, December 15, 2010:

http://atsb.gov.au/media/2894370/ao2008003.pdf

[Edit:  I see now that the original report, downloaded from the link posted in the initial post to this forum, is about 25 percent larger than the currently available final report.  Hmmm...might be interesting to see how the editing was done...perhaps some controversial section was edited out of the final-final report? (grins)]

I don't think I would like to fly or ride on a backup battery-powered 747!  They are of course designed for this possibility but I would prefer to not use up ANY of my backup components.  Standby instruments should do just as their name suggests, namely 'standby' quietly, and be seen but not needed!

[Phil Bunch]

Verifying my initial guess, it appears that the initially posted "final report" was probably an earlier draft.  The Table of Contents isn't a reasonable one.  Since they differ by about 25% in size, perhaps there is other editing that the presumably inappropriately posted draft needed.

It must be quite a zoo scene to get through the final editing of such a report, with all the stakeholders and the need for exceptional accuracy and objectivity, as well as rationality and balance, and a zillion other things.  Just thinking about the review process gives me a headache, having been exposed to such things during many years of my work as a member of an ISO standards development committee (medical radiography standards, unrelated to aviation).

[Peter Sagar]

Verifying my initial guess, it appears that the initially posted "final report" was probably an earlier draft.  The Table of Contents isn't a reasonable one.  Since they differ by about 25% in size, perhaps there is other editing that the presumably inappropriately posted draft needed.

It must be quite a zoo scene to get through the final editing of such a report, with all the stakeholders and the need for exceptional accuracy and objectivity, as well as rationality and balance, and a zillion other things.  Just thinking about the review process gives me a headache, having been exposed to such things during many years of my work as a member of an ISO standards development committee (medical radiography standards, unrelated to aviation).

A friend of mine is a scientist with the ATSB in Canberra, and he informs me that there is quite a rigorous internal peer review of all reports before they are published, in addition to any reviews by other stakeholders.

Peter.

[Will]

Think about the EgyptAir 990 crash report, and what the debate over the final conclusions must have been like.  I'm sure they lost sleep, thinking "we're gonna catch hell for what we're about to say."