The underwater search for the missing Malaysia Airlines (MAS) flight MH370 covering an area of 60,000 sq km in the southern Indian Ocean could be completed by May based on the current weather trend, said Malaysia's Department of Civil Aviation (DCA).

DCA assistant director, flight operations sector, Capt Mior Nor Badrishah Mohamad, said the weather beyond May could be challenging for the team as the waves could reach a height of between 12 and 15 metres.

"We are not sure whether we would be able to locate the aircraft but we are 100 percent sure we can complete the search on 60,000 sq km," he said at a technical briefing on the latest developments pertaining to the MH370 search, at the DCA office here today.

At present, Mior Badrishah said, a total of 18,623.26 sq km or 31.04 percent of the underwater search area had been completed by the vessels Fugro Equator, Fugro Discovery, Fugro Supporter and Go Phoenix.

He said the search, which is in the third phase, was on the right track based on the Inmarsat satellite data and aircraft performance data.

The first phase of the search operation to locate the aircraft was the transition phase before the second phase commenced on June 1, 2014, for a bathymetric survey which was completed on Dec 17 last year.

Asked what if the aircraft could not be located, Mior Badrishah explained that the search team would be pulled back while all experts and the respective governments would sit down together to discuss the best way forward with all the available data.

"There is no time frame but we are sure the search is being done in the correct place," he said.

To another question, he said there was no shortage of equipment for the search operation and believed the world's best equipment had been brought together with the best technical experts and personnel deployed for the mission.

When asked of the possibility of the aircraft being buried deep in the mud and the wreckage impossible to be located, he said: "Even it was covered by mud, we can still see the shape of the aircraft".

During the 30-minute briefing, media personnel were also shown a recording of a bathymetric survey providing a detailed map of the sea floor topography of the search area taken sometime in August/September last year.

The MH370 Boeing 777-200ER aircraft carrying 239 passengers and crew disappeared from radar while enroute to Beijing from Kuala Lumpur on March 8.

Its flight path is believed to have ended in the southern Indian Ocean.

Yesterday, DCA director-general Datuk Azharuddin Abdul Rahman announced that the missing MH370 was deemed an accident and all 239 people on board were presumed dead.