LONDON (AP) — British aviation investigators reported Wednesday that a 2013 fire on a Boeing 787 Dreamliner started in a battery for the plane's emergency locator transmitter — a finding that triggered recommendations to improve safety on similar battery-powered equipment on planes. The Air Accidents Investigations Branch said in a report that crossed and trapped wires under the battery compartment created a short circuit on the Ethiopian Airlines-operated plane parked at London's Heathrow Airport on July 12, 2013.