Porter Airlines is confident the CS100 aircraft on which the airline has built its expansion plan will prove to be as quiet, if not quieter than, what Bombardier promised.

But if it isn't, Porter isn't locked into the agreement, CEO Robert Deluce said Friday.

"If the aircraft doesn't meet the specs that we have been given by Bombardier, very simple -- we don't want their airplane," Deluce said during a speech at the Toronto Region Board of Trade.

"My guess is they're going to bring an airplane that performs better than they've guaranteed, because we have some performance penalties and guarantees in our contract."

Porter Airlines has asked the city, Transport Canada and the Toronto Port Authority to amend a tripartite agreement that prevents jets from using Billy Bishop Toronto City Airport except under special circumstances.

The expansion plans will also require Porter to extend the island's runway by 168 metres at both ends, a process that will involve filling in part of the lake.

Porter has already placed a conditional order for 12 CS100 aircraft, with 18 options, worth about US$2.08 billion. The aircraft will allow it to fly to Los Angeles, Florida, Calgary and the Caribbean from Toronto.

Deluce has promised that Bombardier's new "whisper jets" will be as quiet as the Q400 turboprop planes that Porter currently operates. The aircraft is also supposed to burn 20 per cent less fuel than any other jet in its class.

But critics point out that the aircraft has never been flown yet, so all of the promises about noise emissions are merely projections.

The aircraft will face its ultimate test when it makes its maiden flight in the next 10 days.

"It's flying very soon," said Deluce. "That will help us get a better handle on what we're dealing with."

The plan has stirred vocal opposition from community leaders and several Toronto city councillors, whose concerns include disruptions to boating activities and increased traffic along the waterfront.

Toronto council recently voted 29-15 to have staff conduct a study on how the proposal would impact the surrounding environment. That study is slated to be completed this summer.

If Porter's plan is approved, the first new planes are expected to be delivered in 2016.