Boeing Co., in cooperation with Air China and PetroChina, will press ahead with a second test flight that will be partly powered by plant oil, company executives said this week.

The test, scheduled for the third quarter of this year, is likely to involve a trans-Pacific trip, far longer than the one-hour test flight that was conducted in China last October, said Stephen Emmert, Boeing's regional director of the biofuel strategy team for China and North America.

The project aims to prove that a China-produced biofuel works, and to ensure "regulators and airlines around the world are comfortable using it for commercial flights," he said.