Planes and ships from Indonesia, Singapore, Malaysia and Australia are scouring two sea areas between Tanjung Pandan on Belitung island and Kalimantan for the missing Indonesia AirAsia Flight QZ8501. Here is what you need to know about the search and locate efforts so far.
Who has sent what
Air force - two C-130 Hercules aircraft, two choppers and one Boeing 737 surveillance plane.
Navy - two aircraft and three mother ships.
Search and rescue agency Basarnas - at least six main vessels, four choppers and tens of small boats.
Air force - Two C-130 aircraft.
Navy - Two vessels - a Formidable-class frigate (RSS Supreme) and Missile corvette (RSS Valour).
Three Malaysian navy ships and one C-130 aircraft.
Air force - An AP-3C Orion aircraft.
The United States, South Korea, Britain, France, India and China have offered help as well.
Where are they searching
Two sea areas between Tanjung Pandan on Belitung island and Kalimantan. The first, lying towards a sea area between Belitung island and the south-western part of Kalimantan, measures 120 nautical miles by 240 nautical miles, while the second, nearer to a sea area between the western part of Kalimantan and Bangka island, is about 180 nautical miles by 150 nautical miles. The areas are 40 to 50m deep.
The 55,800 square nautical mile total search area has been split into seven sectors. Indonesian Armed Forces planes are focusing their efforts in three areas, and aircraft from Singapore and Malaysia in another two areas each.
The search covers a part of the Java Sea, which spans about 167,000 square miles, or about 603 Singapores (Singapore's land area is about 277 square miles). Weather conditions in the area towards the end of the year are said to be violent but not unmanageable, aviation experts said.