BY : AP

A Chinese military helicopter that crashed during earthquake relief efforts last month had suffered engine trouble shortly before going down, a state news agency said Friday.

In an interview with the pilot's widow, the official Xinhua News Agency said the Russian-designed Mi-171 had made a forced landing when its engine overheated during a mission just prior to the March 31 crash.

That revelation suggests mechanical problems might have been a factor in the accident, which killed the five-person flight crew and 14 quake victims the helicopter was carrying out of deep mountains after road links were destroyed by the March 12 quake.

Previously, Xinhua had said only that the helicopter crashed after encountering turbulence and fog. The wreckage was found 10 days later near the town of Yingxiu in Sichuan province.

The pilot, Col. Qiu Guanghua, had been just one month from retirement, Xinhua said. He and the rest of the crew have been posthumously honored among the official heroes of the rescue and relief operation.

The magnitude 7.9 quake killed 69,186 people, with 18,457 still missing, according to the government. About 5 million people were made homeless.