It was party time for Singapore Airlines and Airbus yesterday as the plane-maker handed its 10,000th aircraft to a very important customer.

For SIA, the delivery of its sixth A350-900 at Airbus headquarters in Toulouse, France, is significant.

Three years after it axed non-stop flights to the United States amid high oil prices and a weak global economy, SIA will use the new plane to resume the service and try to reclaim some of its lost glory.

From Oct 23, the A350-900 - touted by its maker to be 25 per cent more fuel-efficient than rival aircraft in the same category - will fly non-stop from Singapore to San Francisco, giving travellers who now have to stop in Hong Kong and Seoul another option.

In two years, when the ultra-long-range variant of the A350 arrives, SIA will be able to operate even longer flights - up to 19 hours - to Los Angeles and New York.

SIA needs to get back in the game quickly; its three-year hiatus has already allowed rivals to swoop in. In June, United Airlines launched a non-stop service between San Francisco and Singapore.

Since SIA's pullout, other competitors, including Middle Eastern airlines like Emirates, have added flights to and from Singapore and their home bases; and from there, to the US.

SIA's re-entry into the non-stop Singapore-US market is not without challenges. In Toulouse ahead of the aircraft delivery, the airline's acting senior vice-president of sales and marketing Campbell Wilson said optimistically: "The market is much, much bigger now than when we served it."

He has a point. But the market is also much, much more competitive now and the competition is "extremely fierce", said Centre for Aviation analyst Brendan Sobie. This will put pressure on fares and yields - great for travellers but tough on airlines.

With a more efficient aircraft, SIA has a fighting chance to make the ultra-long-haul flights work. Three years back, it could not.

The aim this time is to stay in the market.