MONTREAL -- Canada's newest airplane made a five-hour test flight Friday, carrying Bombardier's hopes for recovering confidence in the company following repeated delays and mounting costs for its new line of passenger jets.

The Bombardier CS300 quietly lifted off under -21C temperatures for its first test flight from the same Montreal-area airport where the smaller CS100 had its first flight in September 2013.

By the company's count, more than 2,000 employees, suppliers and customers were on hand to witness the event.

The CSeries planes are part of a new family of narrow-body, twin-engine jet that Bombardier has been developing for several years. They are larger than Bombardier's earlier CRJ jets and Q400 turboprops and move the company's product lineup closer to a market segment that has been dominated by smaller models of Boeing and Airbus jets.

The CS300 is a 135- to 160-seat aircraft slated to enter into service in mid-2016, about six months after the smaller CS100. The CS300 has attracted 180 firm orders so far, representing more than three-quarters of the overall program's 234 firm orders to date.

Bombardier is continuing to conduct a series of required test flights. Delays in getting the CSeries ready have increased costs of the program, most recently estimated at US$5.4 billion, and contributed to a decline in Bombardier's stock price.

Test flights for the CS100, about four metres shorter in length than the CS300, were suspended for three months last year following an engine failure.

The company said test results have confirmed the promised performance of the CSeries aircraft. It said the engines are as quiet as its Q400 turboprop, a key factor in getting approvals that would allow Porter Airlines to fly the CS100 from Toronto's Billy Bishop airport.

David Tyerman of Canaccord Genuity called the CS300 first flight a "secondary event" and said the bigger concern is the CSeries order book which, he said, contains some orders that are viewed as questionable.

"This is just a stretch version of the other one, so presumably they have a fairly good idea of how things are going," Tyerman said in an interview.

Bombardier's B shares have plummeted 39 per cent since the end of 2014 and 47 per cent since the first test flight of the CS100, amid financing concerns that prompted the company to obtain $1.1 billion in equity financing, seek another US$1.5 billion in debt financing, suspend its dividend and pause development of its Learjet 85.

CEO Alain Bellemare joined the company this month when Pierre Beaudoin stepped away from the top management post to replace his father as chairman of the company's board. Bellemare said Bombardier is at an important "inflection point."

"We've been struggling, we have had our share of challenges because of just the pure workload of developing such a complex and high-tech aircraft...but we're getting close to the goal line so I feel good about where we are," Bellemare told reporters in the hangar that houses several CSeries test aircraft.

Mike Arcamone, president of Bombardier Commercial Aircraft, said the company will let the CSeries performance "speak for itself" instead of responding to suggestions by competitors that the company's future is uncertain.

Swiss International Air Lines has ordered 30 of the aircraft for delivery beginning in 2016. Peter Wojahn, the Swiss airline's chief technical officer, was at Friday's test flight and said Bombardier has assured him of the plane's performance and its ability to finance the program.

"The feedback I got back ..gives us quite a good impression and a good feeling that the program will be a success and that we will get what we expect," said Wojahn.

Bombardier is aiming to secure 300 firm orders -- or more than two years of peak production -- from about 20 customers by the time the CS100 is certified by year end.

The company said Friday that initial deliveries could be pushed a few weeks into 2016 if customers need more time for training.