After 11 years of development, Bombardier celebrated the maiden flight of its largest commercial jet, the CSeries 300, on Feb. 27 even as questions remain about the program's long-term financial viability, Bloomberg reports.

The flight at the company's aerospace operation in Mirabel, near Montreal, Canada, comes after delays and C$2 billion ($1.6 billion) in reported cost overruns. The delays also were reported by Bloomberg to have contributed to the departure of Bombardier CEO Pierre Beaudoin on Feb. 12.

Bombardier celebrated the maiden flight of its CSeries 300 aircraft on Feb. 27. Source: BombardierThe CS300 airliner – bearing Canadian registration markings C-FFDK – departed Montréal–Mirabel International Airport at 11:00 EST and returned at 15:58 EST. It reached an altitude of 41,000 feet (12,500 meters) and a speed of 255 knots (470 km/h).

The aircraft can seat as many as 160 passengers and has garnered the bulk of the 243 firm orders Bombardier has collected for the plane and a smaller, 125-seat version, the CSeries 100. The smaller jet began flight tests in September 2013. It suffered an engine malfunction last spring during ground testing that forced design changes. The CS100 is expected to enter commercial service later in 2015, followed by the CS300 in mid-2016.

Republic Airways Holdings, which operates regional flights for several major U.S. carriers, and leasing firm Macquarie AirFinance are reported to be the largest CSeries buyers. Both have ordered 40 of the planes, mainly the CS300.