The crash in Mangalore killed 158 passengers and crew
Aviation investigators in India have recovered the crucial "black box" that records all flight data, three days after an Air India Express plane crashed in the southern city of Mangalore killing 158 passengers and crew members.
The box itself was found still operational, with the "main memory" left intact, officials from India's Directorate General of Civil Aviation (DGCA) said Tuesday.
The cause of the worst air disaster in India in a decade was still unknown, officials said.
Only eight people among the 166 passengers and crew survived, mostly by jumping out of the plane that split in half and burst into flames soon after landing on Saturday.
Among the dead were 19 children and four infants.
Black box: key to air crash investigations
Modern black boxes, which are actually orange in colour, record up to 300 factors of flight including:
Airspeed and altitude
Heading and vertical acceleration
"Analysis of the flight data will be conducted in the next fortnight," an official probing the tragedy said.
"Similarly, analysis of records pertaining to the crash will take a couple of weeks."
The cockpit voice recorder of the Boeing 737-800 was found on Sunday.
Aircraft manufacturer Boeing said it was sending a team to help the investigation.
A preliminary replay and analysis of audio taped conversations between air traffic control at the Bajpe airport and pilots, recorded moments before the crash, was carried out on Monday, officials in New Delhi, the Indian capital, said.
Air India Express, a budget airline operated as a subsidiary of the state-run carrier, has been criticised for lax safety procedures.
Many of the crash victims were migrant workers returning home from the Gulf.
"Regrettably, in certain sections, this accident is being used to malign the functioning of Air India Express and implying that the operational and engineering infrastructure is inadequate," the company said in a statement.
"We wish to reiterate here that Air India Express meets all regulatory requirements and has been always well equipped to handle the operations and maintenance of its fleet to established standards."
Indian media and some aviation experts have said the runway at Mangalore's "table-top" airport was not wide or long enough and may have given little room for the pilot to react after landing.
India's last major plane crash was in 2000, when 61 people were killed after a passenger jet plunged into a residential area near the eastern city of Patna.
The country's air safety record has been good in recent years despite the rapid increase in airlines keen to serve increasingly wealthy domestic customers.