When a fleet of new planes goes into daily service, problems surface that pre-production testing was not able to bring to light. The 787 is no different. But, when three things of no great importance were reported in three days, the media went into a feeding frenzy.
On January 7th, a battery on a Japan Airlines 787 caught fire while the plane was parked on the ground. Just as the battery in a car starts the engine, a battery on the plane is used to start the Auxiliary Power Unit (APU). The APU produces electricity and pressurized air to power the plane when it is parked. The APU is designed to operate unattended. If any fault is detected, the APU automatically shuts itself down. In case of a fire, an alarm signals the ground crew to determine whether the fire extinguisher needs to be used.
If a battery fire were to develop during flight, a warning would go off in the cockpit. The pilots could then press a button to discharge the APU's fire extinguisher.
Lithium ion batteries have twice the storage capacity of nickel-cadmium batteries. More stored power means more potential to overheat if a battery fails internally or is overcharged. Lithium ion batteries have been known to catch on fire in laptop computers and on hybrid cars. Boeing designed the 787 - the first airliner to use lithium ion batteries - with this potential in mind. A possible area of concern is whether the use of lithium ion batteries on the 787 call for more safeguards than those already in place.