FAA made a mistake with Lithium, and they know it. It is such a seductive technology, who wouldn't want it integrated with such a groundbreaking airplane (787)....
In reading the considerations, the motive for allowing the LiIon battery is clear, Economics, not airworthiness, or safety.
It reads like a waiver without a safe foundation, written to ennable an experiment in commercial carriage
That is not the FAA's purpose. The purpose of the FAA is to say NO....until safety is satisfied...
How do we know? Because the AD makes it plain that their mission was avoided.
They were not satisfied with Lithium safety from the beginning, all the considerations are written to prevent fire.....or to mitigate one that starts
Which makes perfectly obvious they are allowing the possibility of fire for a system that is not critical to safety, to flight, or to their mission, only to money
Now that the horses have bolted the corral, they command Boeing to "demonstrate the safety of the system" while allowing, in their initial approval, for unsafe conditions they now say are insufficient?
Hersman is correct, fire is not expected. She must not have got the memo from FAA....