Qantas B744 Total electrical failure?

[alph2z]

I wonder how close they were to also losing the battery bus.

Any ideas on how the battery relay-control units works.
.

[sevenstrokeroll]

Oh for the days of:

Oh for the days of:

the wind up clock.

direct linkage to the flaps/hydraulics...

direct linkage to the gear hydraulics

direct manipulation of the outflow valve by cable

direct control linkages.

what happened to : KISS?

[Cider30]

Landing

NSEU,

You mention one of your primary concerns on a dead ship would be lack of attitude information.

I am thoroughly impressed with your insight on the 744 systems and would really like to hear how you would land in this situation.

Assuming that 30 minutes of back up power is insufficient to get to a slab of concrete, lets just say at least 2 hours from anything, I would think in 30 minutes you could get the aircraft to VMC conditions. Again for arguments sake, lets say fuel is not a limiting factor, so by some form of navigation (pax mobile GPS or star navigation) we get ourself overhead a well lit up airport, good horizon, hell lets even say the sun came up.

What would your considerations be and what would you do to get this thing on the ground.

Cider30

[HotDog]

"Is there an aircraft engineer on board?

No, they were made redundant by "fail safe" computers and pilots, instructed only to the "need to know" level of system operation.

[Brian Abraham]

What would your considerations be and what would you do to get this thing on the ground.

Reading the posts would I be correct in saying a flapless gear up landing? Unless you knew where to chop a hole with the crash axe to get at the uplocks? Then having got the gear down no brakes? Exciting or just another day at the office?

Don't worry lads these aeronautical thingies are designed to a 10^-9 failure standard.

[amos2]

If you back in history you will find that a BAC 111 or Viscount, I'm not sure which, suffered a total gen failure in IMC at night in the UK some 20 odd years ago, perhaps longer...I'm scratching the memory bank here!...

They ended up on battery power only, lost that on descent still IMC, and ploughed into the ground from about 15 grand inverted, I think!

It was a freighter. The details will be in the archives somewhere.

[Krakatoa]

I seem to remember a British Eagle Viscount crashing in Germany in the sixties, think it was an electrical problem.

Anyway I can hardly wait for the "..all electric 787.." There is something to look forward to !

[NSEU]

"What would your considerations be and what would you do to get this thing on the ground."

I'll leave these sort of things to the real experts I'm not a pilot, but I've been in the aviation industry long enough to have some understanding of the problems that pilots face... including the fact that the buck stops with them.... with radio comms dead (or limited by line-of-sight), there is no one out there to help you... That's why I can't stress enough having a good understanding of the basics of flying and airplane operation.

The artificial horizon is a key element in flying the aircraft straight and level. Pilots are taught at a young age not to fly solely by the seat of their pants (i.e using their human senses of sight, balance, etc). Imagine what would have happened if the QF crew was over the Antarctic, lost their artificial horizon and experienced the whiteout effect that led to the destruction of the Air New Zealand DC10 many years ago. Also, as someone mentioned, without electric power, the windows are going to start fogging/icing up with lack of window heat... so you really can't rely on an outside view).

Re the newspaper article...

"A fault with galley drip trays found on a number of Qantas planes may be a problem for ageing Boeing 747s around the world."

I think some of the newspapers have gone a little overboard with the "ageing" aspect. Replacing new aircraft for old is one way of fixing a problem, but Japan Airlines is a good example of what you can do if you throw enough money at your existing old fleet. Their planes are immaculate and, apart from the IFE systems, hardly anything goes wrong with them (ok, so they crashed one 747 into a mountain... but this is another good example of cumulative errors leading to one big one (including problems not envisaged by the designers)). However, accidents and incidents often lead to better airplane design..... albeit at cost to human life.

Qantas, too, is still flying around at least one Classic 747, which is testament to their old system of maintenance and a good basic airplane design. The 747-400's are much younger than this and still have many years of productive life ahead of them. I wouldn't write them off just yet

"Again for arguments sake, lets say fuel is not a limiting factor, so by some form of navigation (pax mobile GPS or star navigation) we get ourself overhead a well lit up airport, good horizon, hell lets even say the sun came up."

I have no doubt about the abilities of pilots to land with basic piloting skills. Fancy electronics are just there to add a greater level of safety. Yes, there have been accidents resulting from optical illusions when visibility is limited, but 747 captains are not "newbies"... they have been around for a long time and know what to look out for.. and CRM allowing, there will be at least one or two people there to help them out.

"Any ideas on how the battery relay-control units works."

Yes (I think).... It depends on what you mean by this. The Battery/Standby Power system is designed around simple electrical relays. In some cases, the coils of these relays receive power from the main busses. If power is lost to these coils, they relax and new circuits are formed using different relay contacts (allowing the (normally) two ship batteries to power "Static Inverters" to generate AC power for vital airplane systems. It is all relatively low power stuff... You're not going to power flap drive motors or run hydraulic motors with this kind of system.

The complex side of the 744 electrical system, however, is main AC/DC bus control. Although a lot of it is configured by simple (heavy duty) relays, there are a number of electronic boxes in the system... GCU's, AGCU's, BCU's, etc. One news article claimed that a single GCU caused the problem, but it seems unlikely. I do know of one situation where one faulty generator during engine startup can cause the electrical system to play up, but more likely it would be the #1 BCU causing the problem in flight. This essentially controls what power goes on the busses by listening to the other boxes, then sending control signals to them. These other boxes then control the power relays. There is a #2 BCU, but it's more of a "slave" than a backup.

Re gear extension without electrics and cutting holes in thick metal paneling... Sounds like a suicide mission to me.... Alternate extension, like normal extension, is a careful co-ordinated affair (to stop the gear doors interfering with the extension of the undercarriage). You really would have to know what you were doing (PA announcement: "Are there four suicidal Boeing undercarriage designers on board please?"). I think the better bet in this situation would be an avionics engineer in the equipment centre with a few rolls of paper towels
BTW, 744 brakes are still controlled the old way.. cables/levers/hydraulics... not that they would do you any good with the wheels still up.

Anyway... I'm starting to put (even) myself to sleep here... (and it's my day off).

Best wishes.
NSEU

[soggy_cabbage]

So, what did we learn?

So, what did we learn?

1, The drain pipes are not big enough, they are easily blocked, Not just on a 747 but it appears most aircraft suffer from this defect.

2, A 70kg NiCad battery will supply emergency power for 45 mins.

Anyone got a suggestion how we can make things better?

(clue.... think bigger)

[the dog74]

[QUOTE]Qantas, too, is still flying around at least one Classic 747, which is testament to their old system of maintenance and a good basic airplane design. The 747-400's are much younger than this and still have many years of productive life ahead of them. I wouldn't write them off just yet

Close, QF still run 4 classics however they are not that much older then the first 744's, i think if memory serves me right one is only 2 years older.

to add a little light on the whole pwr issue of QF2, main bat powers static inverter and when hopefully power switch is in auto ac stby contactor provides power to ac bus 3 ie capt's instruments rmp's ect also powering dc bus 3 via the t/r.

not to sure in this case even if APU on 744's was available for elec use ie inflight start if it would of helped i heard there was a bucket load of fluid in there affecting both e1 and e2 racks. also was told about several others aircraft having problems with the drip shields.

Now lets not forget that ALL aircraft suffer things like this from time to time the old 744 is a great beast and the guys that maintain them do a great job.I think this is just a little reminder that more attention needs to be paid to these aircraft in heavy checks. The old rule of if you can't see it properly, pull it appart till you can, applies.

My thanks to all the men and women who service maintain and fly the mighty 744 (aswell as all a/c) keep up the top job.

[amos2]

NSEU has said...

"with radio comms dead (or limited by line-of-sight), there is no one out there to help you..."

So, if radio comms are not dead...who is out there to save the situation?

You, perhaps?

Do you really know what you are talking about?...

I doubt it! ( how many hours do have as an airline pilot? )

[NSEU]

"So, if radio comms are not dead...who is out there to save the situation?

You, perhaps?"

Sometimes a different perspective (and access to more detailed manuals ), offers insight into solving previously unsolveable problems.

"how many hours do have as an airline pilot? "

Ouch.. that hurt

Glad you didn't ask me how many years experience I've had unblocking drains...

[flt_lt_w_mitty]

This raises the question: For whatever reason, poor design, poor maintenance or both, a common point in an a/c has been compromised and the electrical supplies severely downgraded. I am VERY surprised that there is no facility to start an APU, although that would probably not have been 'connectable' as it doubtless was bussed through the same area.

As someone else has said, had this happened further out within the operating area of a large passenger plane, it would probably have been inexplicably lost.

Do we therefore

1) Accept this as the statistically acceptable risk?

OR

2) Ensure that at least a separately powered attitude indicator with sufficient endurance for the operating area is fitted, PLUS a back-up independent nav system as also suggested. A venturi driven AI would also be fine - and cheap. A battery of greater capacity than ?30/45? minutes and located away from the 'danger zone' would help.

With these, gravity drop on the gear (as per the 737) and (presumably) self powered engine tachos, a crew has a more than reasonable chance of getting the a/c down somewhere in one piece. The battery could even be turned off when initial actions are done, the recovery made on the back-ups and the battery used at the end for flaps and gear etc.

Is the cost etc of this justified? Over to the floor.

I should add - kudos to the crew!

[mumbo jumbo]

Amos2, do pay attention you old f@rt! We try to make allowances for you geriatrics, even if you do know how to suck eggs already. However, your bad tempered attack on NSEU is unwarranted as he has never claimed to be a pilot, like wot you once was.

Thankfully, we also have technicians and engineers who are well versed in the systems that we have to deal with and they do help with giving us young whippersnapper pilotos some points of reference. Retired old farts like Amos2 and his grumpy old brother, 411A, should at least try and understand a bit better the stuff they are reading whilst their cocoa and slippers are being prepared by their carers.

[CargoMatatu]

Lovely!

[amos2]

So, how many hours do you have unblocking drains?

[The Flying Pram]

You can now fit a paperback sized complete blind flying panel in your Ultralight / Homebuilt which has solid state gyros and (I think) GPS built in. As the "statistically impossible" has now occurred, maybe the powers that be should be thinking about fitting these, or even providing them as a Quick Fit unit complete with a long life primary battery, stored somewhere readily accessible. This would give the crew a much better chance of locating a suitable runway even if they did have to put it down wheels up.

[spannersatcx]

FCC's (Flight Control Computers) and FCU's (Flap Control Units) are powered by 115vAC STBY PWR and 28vDC main BAT BUS and most bits in the flap control systems have AC and DC CB's as do a lot of systems, so as long as you have STBY PWR and 28vDC power a lot of systems still work, and are indicated on the EICAS screen that is still powered. As the a/c still had HYD power and Pneumatics (eng's were still running) then flaps LE and TE will still operate. The assymentry occured after due to various things being out of sequence (to keep it simple)

Do not be confused with primary and secondary electrical control/operation of flaps this is an entirely different system and in this scenario were not used.

Gear is a similar scenario, electric motors are use to release the gear locks and through cable linkages and gravity doors are release, pushed open and gear falls down and locked by geometric locks, doors stay open.

p.s. I have many hours experience of unblocking drains, normally cause by the CC putting Red Wine and Milk down the drain which funnily enough congeals in to a large imoveable blob, even though we have big signs on galleys that they (CC) are not supposed to pour it down there. So poor maintenance - no, poor CC maybe, we shall have to see.

[skiesfull]

Let's face some facts instead of worrying over what might have been. Jan 22nd will mark the 38th anniversary of the first commercial flight of the 747. How many total electrics failures have occurred since then? Is it an acceptable risk?
This incident was resolved by the crew's skills and initiative without injury to anyone - yes they were fortunate that it happened in daylight, good weather and only 15 mins from a major airfield. So what will be the outcome?
1) A directive and possibly a modification from Boeing regarding drainage close to the electrics bay, involving regular inspections.
2) Possibly a recommendation to retrofit at least the -400 fleets with an ISFD, giving 150 mins of altitude/attitude/speed.
3) A checklist from Boeing in the non-normal QRH referring to action following toatl electrics failure, including what flaps and gear -if any- are affected by downgraded electrics.
As for RAT's, the only 4 engined a/c I flew with an ELRAT was the VC10 -when it was deployed following all- engine flame-out due fuel mismanagement, it promptly separated and is currently on the sea bed somewhere between Hong Kong and Tokyo, I believe. Perhaps 411A can recount the number of times the L1011 RAT was used for real?
When pax were able to visit the cockpit I often had requests to try a hand-held GPS - it never worked in the cockpit.
Safety is furthered by paying close attention to incidents and accidents, and making carefully considered recommendations - not by knee jerk reactions.

[NSEU]

2) Possibly a recommendation to retrofit at least the -400 fleets with an ISFD, giving 150 mins of altitude/attitude/speed.

The 744 ISFD is currently located on the lower MEC racks directly below the BCU/GCU's which were waterlogged. A relocation might be in order in light of this event