Indonesian authorities say engine failure likely doomed the military transport plane that crashed into a residential neighborhood on the island of Sumatra this week, killing at least 141 people.
Air force officials said Thursday initial findings indicate a propeller malfunctioned and that the Hercules C-130 failed to gain enough speed shortly after taking off from an air base in the town of Medan.
Eyewitnesses reported seeing the 51-year-old plane emitting smoke and flames as it made a sharp turn to the right, apparently in an attempt to return to the airport before crashing Tuesday.
The plane slammed into two houses and a hotel, exploding in a ball of flames and causing widespread damage. Authorities prepared Thursday to call off the rescue effort, after no bodies were found over the previous day.
Officials say 122 people were on the plane - a significantly larger number than originally reported by Indonesia's military. Most of the passengers were military personnel and their families.
Some families of the victims have said the passengers paid the military to get on the flight. Military officials have denied the claim, but have said they will investigate if rules were broken.
The accident raised fresh concerns about the country's military aviation standards. It is the sixth deadly crash involving an Indonesian air force plane in the last decade, according to the Aviation Safety Network.
Indonesian President Joko Widodo on Wednesday promised a full investigation and a review of the country's aging defense equipment.