Indonesia's largest low-cost carrier Lion Air has been criticised after a preliminary investigation into last month's Boeing 737 crash off Bali found a young, second-in-command pilot was at the controls at a "critical time".
The National Transportation Safety Committee said in a report that the budget carrier should immediately implement a number of safety measures related to landing procedures carried out by pilots, as well as to ensure pilots are properly trained.
The report, released late on Tuesday, did not give an exact cause of the crash, but ruled out any major problems with the new Boeing 737-800 passenger jet.
Weather reports indicated that there was a sudden loss of visibility in the area, it said, adding the second-in-command was in charge seconds before the plane crashed into the sea just before the runway.
A spokesman for Lion Air, which has had six landing accidents in the past decade, said on Wednesday the airline had not "received the report yet".
All 108 passengers and crew survived when the passenger jet undershot the tourist island's main airport runway and belly-flopped into the water..
The cause of the crash has potential implications for the reputation of one of the world's fastest-growing airlines, which is fighting to be removed from a European Union safety blacklist even as it buys record volumes of Airbus and Boeing jets.
Indonesia has also failed U.N. agency the International Civil Aviation Organisation's standards for aircraft operations and maintenance, and as a result American regulators have imposed restrictions on them starting or increasing flights to the United States.
The preliminary report said that the 24-year-old second-in-command, who had 1,200 hours of flying experience, was in control during the descent into the airport and reported that he could not see the runway 900 feet above ground.
The captain then switched off the auto-pilot and the second-in-command handed over controls to him at 150 feet - or 1 minute, 6 seconds before the crash - after repeating that he could not see the runway.
One second before the crash, the pilot commanded a "go-around" and attempted to abort the landing, but it was too late.
The report recommended Lion Air "review the policy and procedures regarding the risk associated with changeover of control at critical altitudes or critical time".
It added the fast-growing airline should also "ensure the pilots are properly trained during the initial and recurrent training program with regard to changeover of control at critical altitudes and or critical time".
The NTSC said it expected to release its final report within the next 12 months.
A person familiar with the matter told Reuters last month that the pilot had described how he felt the 737-800 passenger jet being "dragged" down by wind while he struggled to regain control.
The NTSC report SAID that the navigational aids and approach guidance facilities such as the runway lights at Bali's Ngurah Rai International Airport were all "functioning properly" at the time of the crash.
Founded by two brothers and travel entrepreneurs, Lion Air has been growing at a record pace to keep up with one of the region's star economies. Earlier this year, it signed a deal with Europe's Airbus for 234 passenger jets worth $24 billion. Two years ago, it signed a deal with Boeing for 230 planes.
At the same time, however, Indonesia has been struggling to improve its civil air safety after a string of deadly accidents.
In 2007, Lion Air was among a number of Indonesian airlines banned by the EU for lax safety standards.
The ban was progressively lifted, starting in 2009, but although it has had one fatal accident, Lion Air remains on the EU's banned list - a predicament it has dismissed as unfair.