I would be interested in links to these plane crashes directly linked to Lipos starting the chain of events that cause a plane to go down, not the lipos being a secondary cause.
You do realise that planes are mostly aluminium and magnesium right? Ever seen a magnesium fire? Like a lipo, water doesn't work. Say for instance, a load of lipos goes up, starts an electrical fire inside the wiring harness in the plane, near the packages of lipos, who would know what came first, the wiring fire or the lipos?
Google is you're buddy
UPS Airlines Flight 6
http://en.wikipedia.org/wiki/UPS_Airlines_Flight_6
On September 24, 2013, the GCAA released its comprehensive, 322-page report on the crash, which found “with reasonable certainty” that the fire which caused the crash
originated in a cargo container which held thousands of lithium batteries