Royal Navy Submarine Joins MH370 Search

The Royal Navy submarine HMS Tireless has arrived in the Indian Ocean to help search for missing Malaysia Airlines flight MH370.

The Trafalgar Class submarine is expected to try to detect the plane's flight recorders in the waters.

Royal Navy survey ship HMS Echo is also due to join the international search operation on Wednesday.

A defence source said: "A Royal Navy Trafalgar Class submarine has recently arrived in the area and is conducting search operations for the flight recorders.

"She was ordered to move from an operational tasking to the search area around a week ago and arrived on station yesterday (Monday).

"HMS Tireless holds advanced search capabilities, but the task in hand remains a tall order and the search area is immense."

Defence Secretary Philip Hammond told his Malaysian counterpart in a telephone call on Tuesday evening that the submarine had arrived in the Indian Ocean.

Flight MH370 went missing on March 8 with 239 people on board. The aircraft took off from Kuala Lumpur International Airport, bound for Beijing.

The three-week search operation has repeatedly shifted its focus as experts analyse radar and satellite data of the plane's movements.

The operation is currently based inside a 25,000-square mile area off Australia's western coast.

The search operation has been hindered by poor weather and repeated sightings of rubbish in the ocean.

Sky's defence correspondent David Bowden said the Royal Navy submarine is a key element to the search.

"Why is she a key element? Because searching from the surface creates problems, not only with the depth, but also with distortion of images," Bowden explained.

"If you're underneath (the water), and you are looking up or along, and if you see anything, you're much closer to it.

"It (the submarine) can go deep and it can listen out for the black box recorder."

Specialist underwater search equipment has been brought in to help find the "black box" data recorder, which is only expected to continue emitting a locator signal until April 7.

Earlier on Tuesday, Malaysian authorities released the transcript of conversations between the aircraft's two pilots.

The transcript confirms Malaysian government claims that the flight began with a routine start.

The published transcript shows the final words from the cockpit to Kuala Lumpur's air traffic control centre were: "Goodnight, Malaysian three seven zero."