Another 'glitch' yesterday ?

Japanese Dreamliner held due to A/C power glitch - CNN.com

Probably because the mis-bored oil stub pipes have been identified and replaced on all Trent 900s.

RR have also re-programmed the FADEC to shut off fuel to an engine where an IP turbine overspeed is detected.

This incident is now history. The problems on the 787 are ongoing and the jury is still out on the battery 'fix'.

I'm just wondering how we're going to know if that fix did it's job? Do we have to wait for a thermal runaway/battery fire and see if it's contained, or is there another way to prove the effectiveness of the fix in real-life service?

It depend on what you mean by a 'fix'.

The previously high number of units going u/s will almost certainly reduce, as the usable voltage range has been limited to prevent overcharging and charging when unit is excessively discharged .

When the next one catches fire is literally anyone's guess although those involved will have statistical predictions worked out.

I've just noticed that the delayed 11.40am UAL125 Heathrow-Houston B787 flight is now showing as cancelled. It's a shame as this flight has had a much better few days for time-keeping. Presumably u/s but that's just supposition.

The RR event and the 787 battery fire both have fixes approve by the regulator. That makes them equal in the eyes of the regulator (nothings perfect)

All the recent talk on this thread is about 787 incidents which have little to any significance to the same level of unsafe conditions in either earlier event.

Time to move on with correlations and look at new events with a safety weighted outlook like any other new product entering service and being adjusted to by the maintenance actions etc.

The bigest difference between the A380 and the 787 issuses is the A380's are further in the past. The 787 issues are close in some peoples memory so the plane is under a microscope. If we get another serious incident with another plane type the 787 will be forgotten

That I can assure you will never hapen !:E

Extensive use of electrical power
 

Didn't the MD11 used to be called "The Magical Electrical Airplane?"

MD11
 

Never heard that term and the MD11 was nothing like the 787. Pretty much a warmed over DC10 with a few computers thrown in just to screw thing up.

Sadly, this is probably true. I don't thing building to regulations always results in a quality product.

But these problems are different in one significant way: For the Rolls engines we (Rolls, the regulators, airlines, etc) are fairly certain we know what the failure mode was and can make an educated judgment about the fix. But in the case of the 787 battery, Boeing admits to not knowing the root cause. Boeing and the regulators are confident that the fix will render further flights safe, within the regulatory definition of safety. And they have some theories about what is happening. But there is still a lot to be learned from in service performance of the 787 battery specifically and the 787 in general, should the root cause prove to be a systemic QA problem across a subset of their manufacturing. So we all watch, since there is still something valuable to be learned.

Read about an Ethiopian 787 being AOG in Beijing for 3 days waiting for a new battery...:hmm:

It is possible that one of the difficulties for Boeing is that the tiniest anomaly in a system will result in no departure or an early return. Wheres on other new a/c they might take the tiny concern with them - no one is going to do that with the 787. This will make the stats look worse and be more public (above).

Boeing have only themselves to blame. If you rush the development and testing, you will have plenty of time to consider the problems during service - or not service - as the case may be.

"If you rush the development and testing"

Given the delay to get the aircraft to the first flight and into operation, I had not the feeling that the development and testing had been "rushed"....

On the contrary, the unizs going u/s will increase now, that the criteria for shutdown (excessive discharge) is more strict. If the number reduces, then only because ground staff is now aware of the issue.

IF the designers have done their job properly, there will be a DIFFERENTIAL between the discharge and recharge minima.

This will ensure that the lowest discharge -level still allows safe onboard recharge...any system which doesn't, is, imho, unfit for purpose.

An electronically -controlled system should be self-monitoring and self-sufficient. It should always be available and serviceable for it's entire service-life.

The human interface is the point of "idiot input",- Very early on, we discussed the "possible" need to over-discharge cells in a real emergency...I suggested that a big, red," reserve battery emergency destructive supply" button could be placed in the cockpit, where the humans could override the system if that was needed to save the aircraft.

doomed
 

For all you doom and gloom guys out theres a reading light out in row 15 seat F as we write but they are safe along with all the other 787's in the air. I was working for the airline which was the first one to get A300-600's and boy did we have big issues, but the press stayed away so it all settled down as will the new state of tech 787.

:rolleyes:

I'd be all with you...
 

IF IT WERE JUST TEETHING TROUBLES AND READING LIGHTS...

but that battery installation unfortunately is destined for "doom & gloom"...

the bird will have to be grounded again after the next major inflight batt issues, which hopefully will turn out to nothing much more than some inconvenient diversions..

But those Li Ions ( at this stage of technical (in) maturity) will have to come out and the battery system will need a major redesign before the bird will finally be safe enough for public transport...

Has the criteria for shutdown been made more strict?

My understanding is that the criteria has remained the same but the charging minimum voltage has been increased to prevent the battery going into shutdown mode.

The shutdown voltage is controlled inside the battery box whereas the minimum charging voltage is controlled by the charger outside the box.

SpeedofSound

That was my understanding too. The armored box brought the instatllation into line with the current RTCA recommendations for LiIon batteries and the charging levels were changed but these were by no means the only change. The specialist teams that were brought in provided fixes for all the potential problems and those that had been found. The intent being that the change-out rate would reduce as well as the failure rates.