Boeing President outlines proposal and its three layered solution.
Mike Sennett is “on”:
Notes taken as Q/A is live, I typed as fast as I could. Sorry for any gibberish notes.
- Design Teams and Context, Data are Items organized for review.
- Commitment to Safety, FAA and the History of Lessons Learned in place.
- Battery is a backup function only, generally a ground device and not critical for flight operations.
- 4 Electrical generators laid out in sequence with back-ups systems.
- Even with All generators, auxiliary power failures, a ram air backs up all emergency level power.
- Redundant and systems exist for all airplane big event failures.
A battery fire is critical of airplane in flight to the extent environmental and structural risks.
Lithium Ion Battery
- Matured and solid technology as of today.
- Many benefits for Lithium -Ion out performs other battery types.
- Provides Significant ground power
- Long lasting
- Testing requires Solution offered, and Does not fail in tests
- Back-up system in the event of failure is covered by four layers of systems
- Interactive management from pilot and back to electronics bay.
- Redundancy in computers and displays for both Pilot and Co-pilot
- Co-pilot is redundant to pilot with his own set of equipment.
- No single failure would ever endanger a flight.
Japan and Boston Event
What happened, small flames in Boston, 3" size, lots of gases and on the other incident no fire just heat and venting.
Battery ventilated the cell to prevent overheating. Other cells vented is a protection mechanism as an electrolytic "smoke", not a fire spread just heat. Battery failed and airplane responded as predicted and as expected under an event. It protected the heat from electrolyte venting sending gases overboard. Damage limited to battery not to the airplane.
A vague euphemistic term for battery overload and shorting event accelerating the rise in heat leading to possibility of fire, if elements are present such as oxygen or fuel in combination of heat.
Venting is a result of a thermal runaway event. Too much heat puts airplane at risk, the two separate events were not do to overcharging, which is the number one fear endangering the Boeing aircraft from the electronics bay. These two events did not have an overcharging problem. Boeing has not yet experienced an overcharging in the 787 ever! The 787 did not overcharge, a worst fear for this battery where it didn't happened, but systems handled the heat event.
Experts needed to increase layers of protection. Top 500 engineers added just for this problem, both inside and outside the company are teaming up over the last months for resolving what happened..
- Auto manufacturing
- Electrical Engineering Labs
- University institutional testing
Gained assurance from outside resources to help resolve problem 200,000 hours expended from all sources for the resolution and mitigation plan.
This is a representation of a process which to understand the battery problem. Hundreds of engineers are focused one mission where they look at ways of stabilizing the battery making risk assessments for all possible condition which can cause a Thermal Run Away.
Changes were made controlling higher and lower operating limits of the charger flow to the battery.
Battery changes in general:
- Venting preventing, isolating cells preventing the spreading of damage
- Cell change
- Case Change
- Wire Bundling
- Dielectric protection to stop venting and propagating heating to other cells nested in the enclosure.
- Charging circuitry wave link is gentler from charger.
Encasement prevents spread of fire, a number one risk.
Enclosure prevents ever having a fire in the first place and vents into enclosure sending gases overboard in a dedicated vent line.
A battery destruction does not endanger aircraft. The risk comes from spreading heat, and fire in the electronic bay from the battery. If smoke, fire, and heat are contained in the enclosure, the aircraft is not endangered during flight or landing on the ground.
Significant testing on enclosure is very good so far and is positive report after six weeks of testing.
Starvation of fire elements does not require and extinguisher system, contained heat and pressure is prevented from building up. After six weeks of testing on new design they have three layers of protection for the battery.
- Event prevention
- Plane protection.
Prioritizing fixes after approval:
- Fleet installation of flying customers,
- And then production aircraft.
Safety is important to the Comprehensive set of solutions for the battery.
787 is extremely safe airplane. Sennett puts his life on the 787 with his family
He demonstrates on a central chart on a fault tree, both likely or unlikely events, 80 potential things that could wrong placed into four categories. Investigative team comes from the field and works back inward from the event to the lab. the other team works from the lab out to the event taking a different perspective.
Two teams, one from assumptions and theories and other team field investigators following actual conditions, parts and performing systems, center on solution.
Conner back on the podium, Q&A
Test Flights & Venting When? Answer: Small amount air or venting releases electrolytic no oxygen no fire. Release reduces heat and no fire. More oxygen had only a small millisecond fires, instantaneously out.
Flights: Single flight to test battery in air.
Laboratory is extensive on the ground will be done in weeks
Commercial Back to Flight? Apology made.
Commercial Airplane will be in the air in more than just weeks. Root cause appropriate correction to parts not known is an unknown root cause is factored over by robust improvement which will not allow this to occur. Try our best against a failure, enclosure allows airplane time to land. Giving Safe flight and landing having the enclosure.
Q: Change from enclosure and system eliminates no risk of fire?
A: Yes no chance of fire!
Confident in battery future with no battery failure. It it ever does, the plane will fly and then land safely. Thousands of fire event with battery failures have happened, with no loss with conventional batteries used in flights today.
End of note taking: