HotDog

So am I, especially since only four generators are available airborne.

mmurray

Somewhere on the first two pages somebody said the four generator control units for the four generators were close together and all got hit by the water from the galley. If that is correct then the supposed fourfold redundancy of having a separate generator associated with each engine is not really redundancy as if you knock out one generator control unit with water you are likely to get the other three as well.

I noticed in Dick Smith's post he said that on his plane the two generator control units are in different physical locations.

Michael

HotDog

Not so. Generator Control Units 1 & 2 plus Bus Power Control Unit 1, are situated on E1 shelf. Generator Control Units 3 & 4 plus Bus Power Control Unit 2, are on shelf E3 at the opposite end of the rack, quite a long distance apart and I find it difficult to comprehend that all of them were flooded.

mmurray

OK that makes more sense from a design point of view. But as you say it makes it pretty surprising if water got them all.

Thanks - Michael

Dick Smith

Why hasn’t anyone answered my very important post regarding what would have happened if this incident had taken place when the aircraft was in the remote ocean area at night? I’m fascinated that no one will touch this in any way. No, I’m not trying to beat anything up. Possibly there will be a simple explanation that the aircraft could have easily tracked to the nearest airport and landed safely. If that is not the explanation, surely we should know.

Surely there is someone reading this thread who is qualified to answer this very important question. I would have thought it is also important for the Qantas management and Board to know the truth – i.e. was there no real problem if this happened in a remote area at night, or could the aircraft and passengers have been lost?

Please, could someone address this important issue?

employes perspective

it would have been lost DICK

Spaghetti Monster

You'd think so, Dick, but sadly they don't seem too interested in the truth when it's unpalatable.

Except when it can be spun into something positive -e.g. "These staples in this wiring loom don't show that our maintenance practices are bad. They actually show how good our maintenance practices are. After all, we found the staples, didn't we?"

stubby jumbo

Dick,

'though not addressing your very pertinent point directly.. This piece from a SMH journo (Paul Sheahan 14/01/08)..... with a lot of credibility says it all really !!!!

Again, applying the REASON MODEL.........Management is your first thick slice of Cheddar !!!


"The Qantas staff, and Qantas itself, simply cannot meet the demand being created by a global mileage mountain that is growing faster than the airlines themselves. Squeezing the frequent flyer program was one of the ways Qantas made a profit of $1.5 billion last year. Squeezing the staff, like sacking a flight crew for taking some chocolates off a plane, or being willing to absorb a strike rather than give engineers a salary increase of more than 3 per cent a year, has enabled senior management to earn hefty performance bonuses.

Qantas is now a caste system, with a yawning income disparity between rich and poor. Had last year's private equity takeover been successful, the top tier of management would have made $60 million from the deal while the rest of the staff made nothing. This grotesquery reflects the modern marketplace, where large investors are fixated on quarterly earnings."

breakfastburitto

Here's a link to the whole article

another superlame

It is not even 2 weeks since the OJM incident and already it is nearly forgotten. The spin doctors have made it go away.
And management barely said 2 words about the whole thing. It just proves my theory that if they don't mention it, it goes away.
Now about that EBA

Andu

Dick, go to the main board and check out the thread on the same subject. Your question has been addressed at length there (some would say ad nauseum, with a plethora of budding Biggles/Hop Harrigans telling us how they would have played "Tim the Test Pilot" after assessing the situation with steely eyed accuracy, and then heroicly dragged the Old Girl safely back to base after descending into VMC conditions (which somehow they knew would be there), pulling a multitude of circuit breakers and then hand flying her in for 'n' jours on limited panel whilst navigating with their (analog, I presume) wrist watches.

All have extensive experience on Play Station 2 or MS Flight Simulator, where their monitor screen has not once fallen off their desk as they perform these acts of derring do.

Regarding the QF spin doctors: I'm interested how the story has changed from the drip tray not being re-fitted after the servicing to it being split.

mmmbop

Dick,

One of the facts being overlooked is that this incident only happened on descent with enough nose down attitude to get the water needed to travel forward to reach the GCUs. As a result the chances of it happening mid Pacific are VERY slim.

If by some chance in a godzillion this had happened over the Pacific (EXTREME turbulence for eg) basic control could to be maintained, however the lack of a standby AH would make orientation in IMC or at night a difficult task. Extreme workload on the Tech crew, but definitely not insurmountable (given a good bit of luck!)

M

ps and b4 somebody states the bleedingly obvious that if we were in extreme turb we wouldnt be able to maintain control of a/c without an AH, my point is that(without trying to say the words exactly) in straight & level cruise this ISNT going to happen

Dick Smith

Is there a chance that water didn’t get to all of the generator control units and some other problem – possibly regarding human factors – caused the complete loss of power? If this is so, surely it should be communicated quickly so a similar situation doesn’t happen again.

I have stated before on this site that whenever I hear of a problem I always say to myself “When can I do that?” It is only by learning of others’ problems that we can hope to not repeat the situation.

maggot

what exactly are you suggesting here dick?? that the flight crew disconnected the remaining gen drives?? if that is what you are suggesting, you could be a little more 'up front' about it. Also, where did you get that idea from??

Short_Circuit

Dick, You are a pilot, how would you go all engines running just fine, cruising fl390, pitch black, stby AH toppling, no moon, a few clouds below?

I suggest you find a glass of water 3/4 full draw a line around the level of the water and keep the water on the line.

or else, plonk!

blueloo

Dick I doubt they would be intentionally disconnecting Gen drives on descent.....not sure what the 744 bus logic is, but maybe they were led to cycling the bus tie breakers in an attempt to reset the logic - in an attempt to regain instrumentation, as opposed to intentionally remove or fiddle with it.

As for standby power, the switching should be fully automatic - no need to manually select it, unless another checklist has told you to select "BAT" as opposed to AUTO. (I assume the selector is similar to 767)

There has to be a case to install ISFDs here - across all fleets. Independant battery powered ISFD which last a couple of hours, providing vastly easier to interpret information, and allowing Capt /F/o to fly without parallex error.

(or is it IFSD....)

capt.cynical

10. Memo Qantas: safety and spin aren't the same thing
Ben Sandilands writes:





Let’s challenge the Qantas spin about how safety conscious the airline is in the aftermath of QF2’s power failure on approach to Bangkok a week ago.

The same jet performed a scenic flight over Antarctica on New Year’s eve.

If the problem had occurred on that flight the naval ships and Japanese whalers might be reaching its last known position about now.

Qantas admits the problem was related to water from a leaking galley seeping into and shorting the normal electrical distribution system, forcing the jet onto a backup battery system.

And all the world now knows that Qantas hasn’t been keeping water from overflowing in its cabins for some time, given the information ‘flooding in’ from passengers.

If it is going to continue to dispatch jets with taped up sinks or wet carpets why isn’t it formulating a safety check list for pilots to refer to in the event of another power failure?

The crew of QF2 acted instinctively. Their cockpit screens were crammed with warnings generated by the power failure. Instead of thumbing through the manuals to trouble shoot a crisis no Boeing 747 crew is on record of having to deal with they just took a shot for the runway.

The Qantas Antarctica flight was cleared to descend to a lower level to ensure a better view during its 12 or so hours away. It imitated the descent QF2 was making when the water sloshed forward in its first class cabin, shortly before lights out but fortuitously close to Bangkok.

The water blamed for this incident which points to shoddy maintenance and possibly more could have sunk to the same sweet spot that shorted QF2 just as readily over the ice cap.

Consider this. Once the back up battery and invertor fails, about an hour after the main supply goes down, there is no radio communication and very little flight instrumentation.

There is no electrically assisted fuel transfers to configure the load in its tanks for optimum efficiency and this jet is at times at least four hours from Australia during which some fuel transfers would be expected to take place.

There is no capacity to restart the engines of a 747 in flight with no electrical power if fuel starvation occurs. But if the jet does make it back to Australia the lack of electrical power means a fast flaps up landing almost certainly with the wheels up as well.

It means a crash.

The spin concerning this incident is unacceptable. If the responsible minister Anthony Albanese is being told by his minders in Transport and officials in CASA that everything is just fine he needs to decide whether to dismiss them before or after the Royal Commission.


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NSEU

The GCU's control the BTB's and GCB's, but the BCU's (Bus Control Units) have control over which power sources actually go on-line. The #1 BCU is essentially the master, with the #2 BCU acting more as a slave rather than a backup. Sounds like it was the #1 BCU which stopped the show (as mentioned, this was one of the units replaced after the incident).

There were no dark and mysterious human factors at work here (other than in the original cause of the problem).

If it's not already written in the manuals, IMHO, it would be better to manually select the Standby Power Switch to Battery instead of leaving it in AUTO, especially if the GCU's are not able to supply a constant/reliable source of AC to the busses. Constant tripping and setting of relays is going to cause extra problems.

Rgds.

NSEU

Seems to be a common misconception....

The normal gear extension on 747's is mechanical + hydraulic. Definitely no gear up landing.

There are steel cables running from the gear lever to the wheel well. Moving these operates hydraulic valves for normal gear extension.

Rgds.
NSEU.

NSEU

Does it really matter?(other than for CG purposes) From any given initial configuration, there will always be fuel available from the wing tanks to feed all four engines (certainly sufficient for four hours of flight). The crossfeed valves are open for most of the flight, so if the outboard tanks starve, one would assume that the inboard tanks would continue to supply fuel to the outboard engines.

(EDIT): Looking at the wiring diagrams, the main crossfeed valves (1~4) are battery operated. It would be up to the crew to decide whether on not they wanted to mess around with the valves prior to running the batteries flat, but I really don't think they need to open/close them.