KARIMATA STRAIT, off Kalimantan, Indonesia: Search operations on board the RSS Persistence - one of a clutch of vessels sent by the Republic of Singapore Navy (RSN) to assist in the search for the wreckage of AirAsia flight QZ8501 - have been hampered by worsening sea conditions. An unmanned underwater search craft has also not been deployed due to the rough seas.
A Super Puma helicopter flight scheduled to take off at 8am on Friday (Jan 2) was put on hold due to weather conditions. The area saw strong winds and heavy rain from 7am to 9am, with visibility so poor that ships had to sound their horns every two minutes to ensure there were no collisions out at sea.
As of 12:30pm local time, weather conditions had improved, with blue skies, minimal cloud cover and swells of about 1m (Sea State 3). However, conditions are expected to worsen later today, with a forecast Sea State of 5 to 6, and the likelihood of isolated showers. Winds in the area are in excess of 40 knots, Malaysian Chief of Navy Abdul Aziz Jaafar said on Twitter.
As of this afternoon, a Super Puma helicopter was launched to continue with search operations, amid heavy rain which reduced visibility to 1.8km, the RSAF said in a Facebook update.
On Thursday, the Autonomous Unmanned Vehicles (AUVs) that arrived at 3pm on the RSS Persistence via Super Puma from Pangkalan Bun could not be unloaded until 7pm due to sea conditions. And they cannot be deployed if the poor weather persists, RSN personnel explained, as the AUV has to be launched from the RSS Persistence using a smaller craft.
"It is not as simple as putting the AUV in the water. There are a lot of factors that could affect the mission plan. The sea state limits the human factor: Typically with high swells, we have a challenge getting to where we want, because we are on a small boat, heavily loaded by our equipment," said MAJ Teng Teck Hong, 39, head (unmanned systems underwater), 194SQN.
"It poses a certain danger to the team. If a high or big wave hits us, some of the equipment may fall overboard. In other to prevent this from happening, there are certain restrictions on what kinds of conditions we can launch in."
HOW THE AUV WORKS
The AUVs - a 1.8m long, 37kg craft bearing underwater survey equipment - can operate at a maximum depth of 100m. The remotely-controlled vehicles hover above the sea bed, while sonar scanners pick up images from each side.
The images are not immediately transmitted back. Instead, while the AUV scans the seabed autonomously, the memory card must be retrieved from the craft after each deployment and the data uploaded to be reviewed manually by trained personnel.
One of the problems this poses is that in the time taken to retrieve and review the images, any items identified may have drifted.
Also, the AUV is not a pinger, and cannot detect signals emitted by a plane's black box. The craft's primary use in the Singapore Navy is to search for mines.
While the search for the missing airliner is now in its sixth day, an officer on board the RSS Persistence said one thing that was not flagging was the morale or motivation of the men.
"We are proud of our men. They have been performing their duties honorably. They know this is not a training scenario but this is a real-life situation," said an officer, who asked to remain unnamed.