Bombardier has pushed its service-entry target for the CSeries airliner back by at least 12 months, saying it will take longer than planned to complete certification flight testing.

The announcement, which was expected, targets service entry of the initial 110-seat CS100 variant for the second half of 2015, with the 135-seat CS300 following about six months later.

Malmo Aviation in Sweden will be the first airline to take delivery of the CSeries, Bombardier says. The airline has five CS100s and five CS300s on firm order.

The last service-entry date given by Bombardier was mid-2014 for the CS100, but after first flight slipped from December 2012 to Sep. 16, 2013 because of assembly delays the company stopped giving a date.

Bombardier said it would give a revised date after it had flown at least two aircraft and completed a review of the flight-test plan. The second CSeries flew on Jan. 3 and the third is close to flying.

“The CSeries program is making solid progress and initial performance results are in line with the company’s expectations,” Bombardier says in a statement.

But flight testing “will require more time than originally anticipated to ensure, amongst other things, that the aircraft has the overall system maturity to support a success entry into service,” it says.

Bank of America Merrill Lynch Global Research expects CSeries entry into service to slip even further, into first-half 2016, and projects development costs will rise to $5.5 billion. This raises the question of whether Bombardier will have to secure additional financing, the analysts say.

The pace of flying began slowly, as Bombardier completed ground testing and configuration upgrades intended to ensure that as much of the flight testing as possible qualifies for certification credit.

Two test aircraft, FTV1 and FTV2, have logged 20 flights and accumulated 250 hr. of ground and flight testing, Bombardier. FTV1 will relocate to Wichita from Mirabel, near Montreal, this week for better weather.

FTV3 will join the test program “in the next few weeks,” the company says. All flying so far has been with the fly-by-wire system in backup “direct” mode, but flights with full fly-by-wire capability, including envelope protection, are about to begin.

Bombardier, meanwhile, has announced that Dammam-based Al Qahtani Aviation has signed a firm purchase agreement for 16 CS300s, with options for 10 more, to be operated by new Saudi Arabian national carrier SaudiGulf Airlines.

Firm orders for the CSeries now stand at 198, and total orders and commitments at 445 aircraft from 17 customers including lessors, Bombardier says. The company’s goal is 300 firm orders from 20 customers by entry into service.