On the Asiana crash, pilot error in multiple respects:
http://www.guardian.co.uk/world/2013/jul/10/san-francisco-777-crash-investigation"The autothrottle was set for 157mph and the pilots assumed it was controlling the plane's airspeed, Hersman said. However, the autothrottle was only "armed" or ready for activation, she said. In the 777, turning the autothrottle on is a two-step process – first it is armed, then it is engaged, Boeing pilots said."
BTW, there was an unnecessarily big scandal in the US about racism when a (now former) summer intern at the NTSB gave a San Francisco TV station the names he had for the Asiana pilots and the TV station was stupid enough to believe them and show them on the air. Here they are:
Sum Ting Wong
Wi Tu Lo
Ho Lee Fuk
Bang Ding Ow
What _idiots_ at that TV station would believe those were correct? Asiana claimed they're going to sue, but most people here believe they should piss off on that and pay more attention to pilot training instead.
On the Heathrow 787 fire, it wasn't one of the LiPo battery packs:
http://online.wsj.com/article/SB10001424127887324564704578630140997356924.html"Inspections of Boeing Co 787s found problems with the wires in three jets' emergency-locator transmitters.
A spokeswoman for United said inspections of its fleet of six 787s are now complete but it found one defective transmitter with a "pinched wire" in an emergency-locator transmitter, or ELT, which has been sent back to supplier Honeywell International Inc for evaluation."