MAGETAN: Investigators sifted through the charred wreckage of an Indonesian military plane today to determine what caused a crash that killed 100 people. The defence minister said all C-130 Hercules would be grounded if mechanical problems were to blame.

It was the third accident involving a military aircraft in just two months and followed complaints that the air force was struggling to maintain its aging fleet and hold on to experienced pilots.

The plane that plummeted to the ground on Wednesday - slamming into several houses and then skidding into a rice field, where it burst into flames — was almost three decades old. But military spokesman Sagom Tamboen insisted it was in good condition, passing both a maintenance and flight check earlier this week.

Others noted that skies were clear and that while pilots were communicating with air traffic control, they gave no indication they were having problems.

“We’re still investigating,” said Tamboen, as teams cut through the twisted, metal fuselage. There were 112 people on the C-130, which was carrying troops and their families from the capital, Jakarta, to Indonesia’s easternmost province of Papua, home to a decades-long insurgency.

It was making several stops along the way and was attempting to land at an air force base in East Java province when it crashed.

Bambang Samoedra, commander of the base, said at least 100 people were killed, including two villagers on the ground. Fifteen others were injured, many with severe burns.

Indonesia’s air force, long underfunded and handicapped by a recently lifted US ban on weapons sales, has suffered a string of plane crashes.

Twenty-four people were killed last month when a Fokker 27 crashed into an airport hangar during a training mission. And just last week another C-130 lost its landing gear and slammed into a house, injuring four people.

President Susilo Bambang Yudhoyono promised a thorough investigation, and said a military budget shortfall was not affecting the safety of the fleet. But Defence Minister Juwono Sudarsono disagreed.

“Ideally, the maintenance cost should be 20 percent to 25 percent of the overall military budget, but at present it’s below 10 percent,” Sudarsono said, promising to ground all C-130s if Wednesday’s crash was the result of technical or mechanical failure.

But human error has not been ruled out, officials said.

The air force has experienced an exodus of experienced transport pilots in recent years, as they sought to join the rapidly expanding network of low-cost commercial airlines formed after the industry was deregulated.

The C-130s are the only aircraft in the Indonesian air force capable of transporting personnel and heavy military equipment - and emergency relief. As such they are essential to the fleet, which covers the huge archipelago.