Day 7 — Indian Ocean

Several "pings" from the aircraft were picked up by satellites for up to four hours after going off radar, according to a NBC News report citing sources. The pings would indicate the plane was able to communicate. But the data would be unlikely to include exact location or direction.

Investigators are increasingly certain the jet turned back across the Malay Peninsula after losing communication. International search expands westwards towards Indian Ocean.

Day 6 — Sign from the sky and earth

Malaysian Transport Minister Seri Hishammuddin dismissed claims that the missing aircraft may have flown for about four hours past the time it disappeared off tracking systems. U.S. investigators suspect that the plane could have flown on for an additional distance of about 2,200 miles (3,500 km). Hishammuddin said their search efforts have always been focused on the South China Sea.

China's civil aviation chief said there was no proof that floating objects in the South China Sea captured in satellite images.

The black box - which is actually orange - is used to record any instruction sent to the aircraft as well as conversations on radio and between the crew. When a plane is lost, the black box pings at a certain frequency for about 30 days and it can be detected within around five or six miles. The box itself is designed to withstand the high impact of a plane crash, the pressures of the deep sea and the high and low temperatures of fire and ice.

Day 5 — Search, search and search

The area of search for the missing aircraft expands to 27,000 nautical square miles covering the South China Sea and Strait of Malacca, with a total of 12 countries participating in the operation. There are a total of 42 ships and 39 aircraft currently involved in the multi-national search. Vietnam says it is scaling back its search in Vietnamese waters for the missing plane.

Sighting of objects in South China Sea: A Chinese government agency releases satellite images of what could be debris from Flight MH370 were released by a Chinese government agency.

A letter appeared on social media, originally written by a worker aboard an oil rig in the South China Sea and send his bosses. The oil rig worker said he believed he may have witnessed a plane plunging toward the water while on fire, and according to the time and location he believed it to have been MH370

Day 4 — Turning back

Two senior Malaysian military officials say missing jet flew for an hour off its flight course and at a lower altitude after disappearing from civil aviation radar. The military had received signals from the plane near Pulau Perak island at 2:40 am.They look further into the possibility that the airplane turned back after flying over Kota Bharu on Malaysia's northeast coast. It's explaining why Malaysia expanded search area to include Strait of Malacca two days earlier.

Interpol identifies two Iranian men as the passengers traveling on stolen passports: Pouria Nourmohammadi (18), and Seyed Mohammed Reza Delavar (29). The two men swapped their passports in Kuala Lumpur, using stolen Italian and Austrian passports to board the airline. A friend of the two men said they were intending to migrate to Europe, but there has been no confirmation from officials on this yet.

Photos and videos emerge of a Malaysia Airlines co-pilot identified as first officer Fariq Ab Hamid entertaining woman inside the cockpit during a previous flight. The airline says it is "shocked" by the allegations and has not been able to confirm validity of the claims.

Day 3 — Small traces

Oil slick results: Malaysian authorities receive test results from the oil slick spotted off Vietnam's coast, which came back negative for jet fuel. The oil turns out to be fuel oil typically used in cargo ships.

Search area widened: Malaysia's civil aviation announces that the search area will double to 100 nautical miles to cover a larger area of the Gulf of Thailand between Malaysia and Vietnam. This came after several leads from the original 50 mile-radius search parameter proved erroneous.

The largest rescue flotilla in Chinese naval history - four warships and five civilian and commercial vessels - speeds overnight to waters between Malaysia and Vietnam. Ten Chinese satellites join the hunt.

Malaysia Airlines announces it will give 31,000 yuan to relatives of each passenger as a special condolence payment.