SINGAPORE, Feb. 11-- The aspiring large passenger aircraft manufacturers from Russia or China or Bombardier will not be a big threat to Airbus and Boeing in the coming 10 years, John Leahy, chief operating officer, customers, Airbus, said Tuesday.

"If you say, will Airbus and Boeing be under threat for the next 10 years? The answer is no. Twenty years, the answer is probably yes. So 20 years from now, it will probably be a Chinese manufacturer that will be a big threat to both Airbus and Boeing," Leahy told a press conference on the sidelines of the Singapore Airshow.

It takes some 20 years to grow a large passenger aircraft manufacturer.

He said that Airbus was established in 1970, but it was not until the 1990s that the European multinational aviation firm began to gain significant ground in the competition against Boeing in the large passenger aircraft market.

China established the Commercial Aircraft Corporation of China, or COMAC, in 2008 with the goal of producing large passenger aircraft. The company has been marketing the twin-engined regional airliner ARJ21 and the C919 family of narrow-body airliners.

The company also presented the cabin configuration of C919 and the four different cabin configurations of the ARJ21-700 such as the hybrid-class, the luxury economy class, the executive aircraft and the business aircraft.

Dang Tiehong, deputy general manager of the Sales and Marketing Department, COMAC, said that the single-isle jet is expected to be in the final assembly phase by the end of this year.

"It is in the phase of detailed design. We are hopeful that the first flight will be carried out in 2015," he said.

Dang said that the progress on the C919 is still in line with initial expectations, despite some revisions to the timetable.

Such revisions are normal with the long-term projects like the C919, as manufacturers typically review their progress regularly and make revisions to the plans accordingly, Dang said.

COMAC has accumulated 400 orders for the C919 from 16 clients, including two companies from outside the Chinese mainland market.

The Singapore Airshow opened Monday evening, with the show open to professional visitors from Tuesday to Friday before members of the public are allowed in on Saturday and Sunday.

Organizers said that the show, now in its fourth edition, is the biggest ever this year with some 1,000 participating companies. Over 70 percent of them are returning exhibitors.