A U.S. Navy P8 Poseidon taxis along the tarmac at Perth International airport to join the search for missing Malaysia airliner, which vanished more than a month ago.

On Friday, as many as 15 aircraft and 13 ships are involved in the search operation in a remote area of the southern Indian Ocean, where officials believe Flight MH370 crashed.

As planes comb a large search zone, thousands of kilometres west of Australia, for possible floating debris, ships are focussing on a smaller area where signals have been picked up consistent with the jet's flight recorders.

Prime Minister Tony Abbott says teams are confident the signals are from the black boxes.

(SOUNDBITE) (English) AUSTRALIAN PRIME MINISTER TONY ABBOTT SAYING:

"We have very much narrowed down the search area and we are very confident that the signals that we are detecting are from the black box on MH370."

(SOUNDBITE) (English) AUSTRALIAN PRIME MINISTER TONY ABBOT SAYING

"We are confident