Sadly, the map tools on carrier websites are needlessly painful, and most coverage apps that you'll find rely on crowd-sourced data -- great if others contribute, but that's not always the case.

ENGADGET

The U.S. Navy initiated reconnaissance flights to map the disaster zone and was moving the aircraft carrier USS Ronald Reagan into position to assist the Japanese government with relief efforts, defense officials said.

CNN: Widespread destruction from Japan earthquake, tsunamis

But the carrier, which has a much smaller European route map than United, has some flexibility to switch to Boeing 767 jets, and a spokesman said it tries to do so in the winter.

WSJ: Nonstop Flights Stop for Fuel