The search for the missing Malaysia Airlines Flight MH370 could take years.

That's according to U.S. Naval Officer Captain Mark Matthews who's part of the search team on the Indian Ocean.

Captain Matthews is in charge of specialised equipment designed to pick up signals from the plane's black box.

But time is running out as the flight recorder's batteries are due to run out within days.

Ten ships and as many aircraft are searching for a trace of the plane, which went missing more than 3 weeks ago.

Reporter James Matthews is in Perth.