The Air China Southwest Branch Company announced that it on Wednesday conducted a successful test flight to the Nyingchi Airport in southwest China's Tibet Autonomous Region.

However, the timing of a regular air service route between Chengdu, capital of Sichuan Province, and the airport is still hard to decide, says Yi Shizhong with the publicity section of the Air China Southwest Branch Company.

"Weather will be the only factor that will decide when the regular air service route will start," says Yi, who declined to disclose the type of the plane used to fly the test flight.

The Nyingchi Airport, built at a cost of 780 million yuan (about 96.18 million U.S. dollars), including investment from the General Administration of Civil Aviation of China (CAAC), is the third civilian airport in Tibet. The other two are in Lhasa and Qamdo.

With a 3,000-meter-long runway, the new airport, situated inside Nyingchi Prefecture and 400 kilometers from Tibet's regional capital Lhasa, was completed on April 28.

Construction of the Nyingchi Airport began in October 2004, with a designed annual passenger flow of 120,000. The airport is located at 2,949 meters above sea level, lower than the other two civil airports.

Nyingchi Prefecture, covering 117,000 square kilometers and bordering India and Myanmar, is known for its humid and mild climate, beautiful landscape and rich natural resources.

About 120 kilometers from the Nyingchi Airport is the Yarlung Zangbo River Grand Canyon, the world's largest canyon that is often referred to as the last secret land.

Because of the geographic location, the Nyingchi Airport is considered one of the most difficult airports to fly into. Meteorological records show the airworthy time at the the airport only adds up to 100 days a year.

(Xinhua News Agency July 13, 2006)