Boeing 787 faces new risk: limits on ETOPS
 

Reuters has this article on possible ETOPS consequences of FAA findings. In the past aircraft needed a good reliability record to apply for longer ETOPS.

Boeing 787 faces new risk: limits on extended range: sources | Reuters

Not so long ago Boeing was working towards 787 ETOPS330. Boeing nears 787 GEnx and 330min ETOPS certification

For illustration I generated an indicative ETOPS90 chart from Great Circle Mapper. I have no idea what limitation the FAA would apply, if at all, for the 787 to re-enter service.
http://www.gcmap.com/map?P=LAX-NRT,+...X=720x360&PM=*

ETOPS 90 looks hard but ETOPS 120 might be ok for a while as most routes would be possible(?), except the Pacific.

Transpac would be it's main market by the way.

From a New Zealand perspective, this is of course a BFD. But how bad a hit would it be for routes between, say, USA and northern Pacific Rim countries?

Downunder-USA would be an issue..

http://i191.photobucket.com/albums/z...psb74c6645.jpg

I guess QF and ANZ hoped for ETOPS 240 at least.

QF now has -9 options only, ANZ is committed.

60 mins more than enough!
 

Well I wouldn't want to go very far from an alternate in the thing until it has got a few trouble free miles under its belt.

There is no regulatory basis to reduce the 787's current ETOPS-180 certification as that allows for a flight to depart with an inoperative APU battery or APU.

So if regulators are going to assume that the APU battery is still likely to fail and inop the APU, that would still allow ETOPS-180.

Was the battery operative during the JAL platform incident?

Is the battery charged during flight?

Only if you leave it on.

What about the main battery failing?

AFAIK there is no MEL item for dispatch with a main battery inop. :eek:

I understand that you are from Seattle and keen to bat for the home team, but even there it is surely understood that the recent issues with the battery were not due to it being inoperative - the thing caught FIRE !!!

Probably that recently published addition by AvHerald tells a bit more about facts and reasons

The bold letters is my addition.
Was quoted repeatedly in the other B787 thread, if a lithium battery is discharged to such a level, no re-charging should occur ! Wether it happened in these cases under investigation is not yet clear. But it should also be clear it´s not only the APU battery that is in jeopardy, the ANA case was the main back up battery.
Regardless what those Boeing PR people release to the public, as long as the real cause is not found the whole set up is not safe. So no release to normal ops should be allowed.

The ETOPS time doesn't matter if your airplane is burning! SR111 couldn't stay in the air for 35 minutes after the cockpit crew reported smoke. AC 797 had a lavatory fire over the heartland of the USA and couldn't land in time to avoid mass casualties.

@ keesje
 

at what single engine speed was that map created?

RobertS975:

That's the point of the metal box.

Look at it this way: Without the box, a battery fire is a critical safety issue. Because it has the potential for bringing down the plane, it must be extremely improbable (< 10E-9 per flight hour). Since it appears that this is not the case, we get the fireproof box. The sales pitch for the box doesn't appear to have a time limit for withstanding a fire (at least none that I've heard). So that means diversion range in the event of a fire will be based on the remaining system capabilities. If you had ETOPS-180 before the battery caught fire, you still have it. That's the position we will be in if the FAA buys the battery in a box solution.

TURIN
If the engines and APU are dead and you are fortunate enough to make it to a runway, the Ship's Battery job is to power the brakes. And if you, and your Ship's Battery is dead, then you're probably going to have a runway overrun. But at least you'll have emergency equipment present and CFRP is strong.


WHBM
And I understand that being from the UK, you must love all things Airbus since they design and build the wings for their commercial airplane families there. :rolleyes:

Yes, the cabling caught fire on JA829J. And in response, Boeing has switched to cabling that is far more resistant to fire and is capable of withstanding significantly higher temperatures (many hundreds of degrees Centigrade).

They've also encased the battery in a fireproof titanium container and shown that there is insufficient oxygen present within to sustain combustion for a few thousandths of a second even with thermal runaway and electrolyte leakage.

ETOPS Limit
 

As a matter of interest, can someone please confirm the current limit on the B777 thanks. Just wonder, if very unfortunately the 787 saga lingers on & with operating restrictions as well, could more 777s fill the gap?

Cheers

777 ETOPS limit is normally 180 mins....however in a previous Airline we had approval to go to 207 mins...From what I remember we had to have a serviceable APU for 207 mins......Distance is normally determined by the airline with regulatory approval...current operation is 1293 nm S/E still air.

The ETOPS time doesn't matter if your airplane is burning!
 

Indeed, and once on the ground you'll have the comfort of knowing that the polar bears won't attack a blazing 787.
.

Kiskaloo, are you sure that you can dispatch an ETOPS flight with the APU inop? if so it's the first I have heard of any aircraft being allowed to do this indeed in my experience we had to have an ETOPS compliant APU which in essence meant that it had to be able to start in flight even having been cold soaked.
You also mention above about the main battery powering the brakes am I to take that the B787 does not have a RAT?

A330 can dispatch for an ETOPS flight with the APU INOP. Emergency generator powered by hydraulics is an alternative power source.

The 787 can dispatch and operate 180 minutes ETOPS with the APU battery inop or even removed, as long as the Variable Frequency Starter Generator is working.

The same restriction applies to the APU itself. You can operate 180 minutes ETOPS with it inop or removed, (as long as the VFSG works).

kaikohe76
As of December 2011, the 777 is now certified for ETOPS-330.

Air New Zealand 777s use ETOPS-240 for their Aukland-Los Angeles route.

kiskaloo
You are trying to bring this discussion into a battle between Airbus and Boeing by your comment.
I have done longhaul on A330's and 767's with no inclination to favour either, but,and it's a big but, I have no intention of stepping onboard a 787 until the cause of the battery problem has been rectified, not the lashup that Boeing is presenting as a "fix".

matkat

It does have a RAT, but it wouldn't provide enough power to operate the brakes at landing speeds, so the battery is the backup.

As above, the main battery is only the backup source for electric brakes. The normal source of brakes is the 28VDC.

The main battery provides power for:
• airplane power-up
• APU start (assists APU battery)
• refueling operations
• towing operations
• electric braking (as backup power source)
• captain’s flight instruments (energizes essential instruments until RAT
deployment)


The APU battery provides power on the ground for:
• APU start
• navigation lights (during battery-only towing operations)

Clearly the 787 isn't short of electric power sources. There are . . .

• four variable frequency engine starter/generators
• two variable frequency APU starter/generators
• three external AC power receptacles
• one Ram Air Turbine (RAT)
• one main battery
• one APU battery
• three flight control Permanent Magnet Generators
• two EEC Permanent Magnet Alternators

All the other power supplies able to supply enough power for braking require a fuel powered generator when when in flight (Engine Generators or APU). The scenario that others have referred to is the "Gimli Glider" where an aircraft ran out of fuel and glided in for a deadstick landing.

My understanding is that many believe that the RAT won't be able to provide enough power for braking as the aircraft slows upon landing (note: I haven't seen this assumption confirmed or denied by Boeing).

So the question is: Will the FAA/JTSB, etc accept the statistical probability being execeedingly low that a 787 would not run out of fuel and lose a battery on the same flight, and therefore have no wheel braking?

I would think, statistically,

would be enough of an improbability that the FAA would not even have to consider it, even if the battery failed on EVERY flight.

Whatever 'many believe', the Boeing manuals tells us this:

There is no mention, in the entire manual, of the RAT having any effect on the wheelbrakes.

Pub User & whatdoesthisbuttondo

Its good to read some good technical facts. I am curious:

1. What drives the three flight control Permanent Magnet Generators and the two EEC Permanent Magnet Alternators.

2. What happens to the captain’s flight instruments etc if the main battery fails to provide standby power until the RAT deploys.

As For the Ram Air Turbine (RAT)

A Ram Air Turbine (RAT) serves as an emergency source of electrical and
hydraulic power. It has no operating time limits, airspeeds, or altitudes.

Nothing to suggest it won't power the brakes on the ground if the battery isn't working AND then somehow the aircraft is then run out of fuel. (I think someone asked about this highly unlikely scenario)

Hi Cool Guys,

Apologies for answering your question by click and pasting,

Permanent Magnet Generators

Three engine driven Permanent Magnet Generators (PMG) are the primary source
of power for the flight control electronics. These power sources are independent
from the main airplane electrical system, and are also independent from each
other.
A secondary source for flight control power is provided by the airplane’s 28 Vdc
bus distribution system, and the main battery. In addition, a backup system is
provided by dedicated batteries to assure positive flight control operation during
temporary power interruptions.

Permanent Magnet Alternators

Two engine driven Permanent Magnet Alternators (PMA) (one per engine) are the
primary source of power for the EEC. PMAs are independent from the main
airplane electrical system, and are also independent from each other.
A secondary source for EEC power is provided by the airplane’s 115v AC bus
distribution system. During engine start, initial EEC power is provided by the
airplane until the PMA is able to provide power. The airplane also serves as a
backup EEC power source if a PMA is inoperative.

So engine driven is the short answer. Like most aircraft, the methods of producing electrical power are Ground external, APU, Engine and Batteries and RAT.

As for you second question about flight instruments if there were no battery and then the RAT deployed? Remember the RAT is only required if

• both engines have failed (and in your scenario there wasn't an APU battery available to start the APU or fuel to run it)

• loss of all electrical power to captain’s and first officer’s flight
instruments

In this (again) extremely unlikely example, I expect there might be a short power interruption until the RAT came online. That would be seconds rather than minutes though.

According to this link (Question 6): https://cramberry.net/sets/63118-757-hydraulics the RAT on a 757/767 requires a minimum airspeed of 130 knots. I don't know what the limit is for the 787, but it is clear that this equipment is designed and certified to provide emergency power in the air, not for electrical braking on a landing roll.

To claim that it has no operating airspeed limits would logically imply that that it could produce sufficient power if it was deployed while the aircraft was being towed. That would solve the battery rundown while being towed problem - just deploy the RAT and the aircraft will power itself! :ugh:

whatdoesthisbuttondo,

Thks for the reply. The 787 sure has a few power sources.

Just ignore eppy's little head banging exercise. I am sure everyone else understands you did not mean the RAT could be employed while towing

Yes! We do!....But the "Boeing Bullcrap" implies that the RAT will be the saviour IF all other power-sources fail.
This clearly isn't the case.

Main engines each drive 3 gennies (2 starter-generators, 1 alternator)

but, hold on, there are 3 alternators, 1 to each engine:confused:

Smell the bull**** yet???

APU drives 2 starter-gennies.
RAT= a glorified windmill-generator..... as such, it's SPEED-DEPENDANT

Basic physics, it turns apparent wind into electrical energy
Irrespective of fuel-levels ,a "dead-engine" scenario is VERY possible

Remember the "over the fence" BA Heathrow flight???
Plenty of fuel, but it didn't turn and burn...that was a "Tin" 'plane, with years of development and Empirical knowledge behind it.

Now we have a Plastic Fantastic and a whole lot of new issues to learn.

SO, We lose both engines in flight.....the batteries are U/s (but that's OK) RAT is deployed, but can't start the APU (making the sweeping assumption that it has enough capacity to start it)

Heroic aircrew plonk it on the ground into the teeth of a 120mph gale!....all our problems are solved....headwind reduces groundspeed and also powers the RAT so the brakes work.

IN real life, As airspeed drops, so will the RAT's output...that presents a real problem, as the likelihood of both batteries failing is currently , statistically very high....2 holes in the cheese are ALREADY lined-up.

"Remember the "over the fence" BA Heathrow flight???
Plenty of fuel, but it didn't turn and burn...that was a "Tin" 'plane, with years of development and Empirical knowledge behind it."
Yes, but even as a lowly SLF. I also understand that the engines, while unable to provide the required thrust, were still producing adequate electrical power. They were turnin and burnin, just not quite fast enough! As I understand, even Capt. Sully's A320, with both engines damaged and not producing usable thrust, the engine generators were still producing electrical power and the A320 remained in normal law until splashdown.

Seems 737 has serious issues
 

Cockney steve.

"Irrespective of fuel-levels ,a "dead-engine" scenario is VERY possible

. . . . . . And later . . . . .

IN real life, As airspeed drops, so will the RAT's output...that presents a real problem, as the likelihood of both batteries failing is currently , statistically very high....2 holes in the cheese are ALREADY lined-up."

I don't agree with you that a double engine failure is "VERY possible", it is an extremely rare event. Especially one where a restart isn't possible. Also to say the likelyhood of both batteries failing is "statistically very high" is also simply untrue.

The 787 has had two individual battery incidents. I'm not sure how you decide a double engine failure or a double battery failure are at all likely. It's a bit sensationalist to suggest you think the aircraft might suffer a double engine failure and a double battery or even single battery failure on the same flight. You also don't know what speed the RAT will provide electric braking down to. I don't know why you're contradicting the Boeing statements about the RAT when you don't seem to have any relevant technical knowledge of it whatsoever.

The same kind of tiny probability leading to a double engine failure and then an unrelated failure of another crucial system would leave most aircraft in a very poor state to land and stop on a runway. A similar example might be a 757/767 suffering a double engine failure followed by a double hydraulic failure. Sure it's possible but let's not pretend its likely or some kind of design fault.

Perhaps but it will still have an accumulator full of 1800psi nitrogen and hydraulic pressure to power the emergency brakes. Somerhing a 787 wont have

Right but the 787 has engine generators, batteries, an APU and a RAT. Do you really think its likely, it will suffer a combination of failures that would leave it unable to stop on a runway?

As I understand it he started the APU.