787 fleet emergency landings and now grounded following battery fires

[kelvedon]

Now I'm not so sad about the 787 going to Jetstar first.

 

[Awesom Andy]

Now I'm not so sad about the 787 going to Jetstar first.

And Qantas might be the smart one who took the compensation money and ran, while still having the choice to buy back in at a later date should the issues be fixed in a satisfactory way.

 

[Sprucegoose]

ANA grounds 787 fleet following latest emergency landing

Now I'm not so sad about the 787 going to Jetstar first.

Quite agree they deserve it. Give me a 767 any day

 

[Blackbird]

Maybe the start of a fix for the battery issues:

Japan: Over-charging preceded ANA 787 battery malfunction

Battery overcharged on ANA emergency landing flight.

 

[samh004]

Maybe the start of a fix for the battery issues:

Japan: Over-charging preceded ANA 787 battery malfunction

Battery overcharged on ANA emergency landing flight.

I saw on the news last night but forgot to post that it received more volts than it could handle, but I wonder how...

 

[Blackbird]

ANA has reported changing batteries on its dreamliners up to 10 times prior to the overheating incident.

Cookies must be enabled. | The Australian

Will be a while before this is sorted.

Add this from Elon Musk of electric car maker TESLA

Elon Musk: Boeing 787 battery fundamentally unsafe

 

[The Rok]

ANA grounds 787 fleet following latest emergency landing

Think Prius in the air!

 

[serfty]

More on this:

Whistleblower Says Dreamliner Batteries Could ‘Explode’

787 Design Flaw Could Be Serious Trouble for Boeing: Aviation Expert

 

[Flying Fox]

OK time to demonstrate my ignorance.

Whilst I understand that the 787 is very reliant on electricity for many of its systems, doesn't the electrical power come either from the engines or from ground power and hence there should only be a small window of time when battery power is required. So why does the 787 need these special batteries? Why can't the 787 use conventional batteries?

 

[serfty]

OK time to demonstrate my ignorance.

Whilst I understand that the 787 is very reliant on electricity for many of its systems, doesn't the electrical power come either from the engines or from ground power and hence there should only be a small window of time when battery power is required. So why does the 787 need these special batteries? Why can't the 787 use conventional batteries?

Power storage/weight ratio?

 

[NM]

OK time to demonstrate my ignorance.

Whilst I understand that the 787 is very reliant on electricity for many of its systems, doesn't the electrical power come either from the engines or from ground power and hence there should only be a small window of time when battery power is required. So why does the 787 need these special batteries? Why can't the 787 use conventional batteries?

My understanding is that there are two large lithion ion batteries in the 787 - one in the forward avionics bay and one in am aft compartment under the floor. The one that caught fire in Boston was the aft battery and that one is used to start the APU. Other aircraft types use pneumatic power to start the APU, but the 787 uses battery power.

I expect the forward battery is used to provide emergency power if the engines are not able to operate the generators, and to get the thing started from cold.

 

[Blackbird]

Power storage/weight ratio?

Correct. Plus 787 has all electric systems and so bigger electric demand.
Article in today's Australian
Cookies must be enabled. | The Australian

"The power packs were chosen by Boeing because the 787 uses electrical systems to perform more functions that older aircraft, and lithium-ion batteries weigh less while providing more energy."

 

[mardy]

Re: ANA grounds 787 fleet following latest emergency landing

Think Prius in the air!

Ironically, the Prius uses NiMH instead, a safer alternative at the expense of some weight.
Not sure what lead to the decision to use Lithium Ion in the 787 as the 777 uses NiCad and they seem to work just fine.

 

[banger2]

Re: ANA grounds 787 fleet following latest emergency landing

Ironically, the Prius uses NiMH instead, a safer alternative at the expense of some weight.
Not sure what lead to the decision to use Lithium Ion in the 787 as the 777 uses NiCad and they seem to work just fine.

Lithium Ion batteries pack more power into a smaller, lighter package than either NiMH or NiCd. Same reason your mobile phone (and other mobile devices) now uses Lithium Ion...smaller, lighter and more capacity. Im sure the electrical energy requirements in the 777 are significantly lower than that of the 787.

 

[straitman]

Re: ANA grounds 787 fleet following latest emergency landing


Failure Modes Featured In 787 Battery Reassessment


By John Croft
Source: Aviation Week & Space Technology

February 04, 2013

The NTSB says the auxiliary power unit battery in the compromised Japan Airlines Boeing 787 “spewed molten electrolyte” and damaged components and structure up to 20 in. from the battery.NTSB
John Croft Washington

Forensic evidence uncovered by the NTSB will force the FAA to revisit whether Boeing met the agency's “special conditions” for certifying lithium-ion batteries on the 787. Included in the reassessment will be whether “extremely remote” failures of the charging and monitoring system, key safety components to prevent thermal runaway that can cause smoke and fires, were correctly identified.

Two of the nine 787 battery certification special conditions issued by the FAA in October 2007 allow for exceptions to normal safety protocols under “extremely remote” failures of the charging of battery monitoring systems. In one case, safe cell temperatures and pressures would not have to be maintained, and in the other, explosive or toxic gases could accumulate in hazardous quantities in the aircraft.

The special conditions, issued by the FAA for a variety of primary and auxiliary uses of lithium-ion batteries, are meant to mitigate any overcharging, over-discharging and flammability concerns not covered by legacy rules. Other special conditions include designing the batteries to “preclude the occurrence of self-sustaining, uncontrolled increases in temperature and pressure;” incorporating a system to automatically control the charging rate of the battery, and providing a warning to the coughpit when the state of charge falls below acceptable levels for flight.

By the FAA's definitions, extremely remote means a failure is not likely to occur “when considering the total operational life of all airplanes of the same type, but nevertheless has to be considered as being possible.” Statistically, “extremely remote” translates to one failure in 10 million flights—the safety threshold generally linked to a hazardous failure.

 

[mardy]

Re: ANA grounds 787 fleet following latest emergency landing

Lithium Ion batteries pack more power into a smaller, lighter package than either NiMH or NiCd. Same reason your mobile phone (and other mobile devices) now uses Lithium Ion...smaller, lighter and more capacity. Im sure the electrical energy requirements in the 777 are significantly lower than that of the 787.

Yeah, but given the size of the aircraft, a few extra KGs in the battery pack is not going to make if any difference to fuel economy, which is really the whole reason for the aircraft in the first place.
It just doesn't seem like the weight loss outweighs the safety challenges in this instance.

 

[Flying Fox]

Re: ANA grounds 787 fleet following latest emergency landing

Failure Modes Featured In 787 Battery Reassessment


By John Croft
Source: Aviation Week & Space Technology

February 04, 2013

The NTSB says the auxiliary power unit battery in the compromised Japan Airlines Boeing 787 “spewed molten electrolyte” and damaged components and structure up to 20 in. from the battery.NTSB
John Croft Washington

Forensic evidence uncovered by the NTSB will force the FAA to revisit whether Boeing met the agency's “special conditions” for certifying lithium-ion batteries on the 787. Included in the reassessment will be whether “extremely remote” failures of the charging and monitoring system, key safety components to prevent thermal runaway that can cause smoke and fires, were correctly identified.

Two of the nine 787 battery certification special conditions issued by the FAA in October 2007 allow for exceptions to normal safety protocols under “extremely remote” failures of the charging of battery monitoring systems. In one case, safe cell temperatures and pressures would not have to be maintained, and in the other, explosive or toxic gases could accumulate in hazardous quantities in the aircraft.

The special conditions, issued by the FAA for a variety of primary and auxiliary uses of lithium-ion batteries, are meant to mitigate any overcharging, over-discharging and flammability concerns not covered by legacy rules. Other special conditions include designing the batteries to “preclude the occurrence of self-sustaining, uncontrolled increases in temperature and pressure;” incorporating a system to automatically control the charging rate of the battery, and providing a warning to the coughpit when the state of charge falls below acceptable levels for flight.

By the FAA's definitions, extremely remote means a failure is not likely to occur “when considering the total operational life of all airplanes of the same type, but nevertheless has to be considered as being possible.” Statistically, “extremely remote” translates to one failure in 10 million flights—the safety threshold generally linked to a hazardous failure.

Thanks for the pic. WHAT A FREAKING MESS.

Wonder how long and how much that will cost to repair and ensure that its all working well.

 

[Blackbird]

Re: ANA grounds 787 fleet following latest emergency landing

The batteries are going to need a redesign and then will have to be certified safe.
See Japan probe finds signs of thermal runaway, short-circuit in ANA 787 battery

Boeing has made a request to the FAA to test fly the 787
FAA may soon allow Boeing 787 test flights | Business & Technology | The Seattle Times

All going to take some time.

 

[oz_mark]

Re: ANA grounds 787 fleet following latest emergency landing

The batteries are going to need a redesign and then will have to be certified safe.
See Japan probe finds signs of thermal runaway, short-circuit in ANA 787 battery

The referenced article does not seem to make mention of the need for a redesign - in fact it does state that the root cause remains unknown. Until the root cause is identified, redesigning may be a bit premature. If anything, it probably brings into question using such large lithium batteries altogether.

 

[lovestotravel]

Re: ANA grounds 787 fleet following latest emergency landing

I highly doubt the 787's will be back in commercial service for months!