Bombardier Aerospace’s case for the C Series may just have grown sounder last month as Boeing announced it would pull the plug on the 110- to 115-seat 717, the proposed Canadian jet’s main competitor. Boeing plans to end production of the weak-selling 717 by the middle of next year, after the last of a backlog of 18 airplanes rolls off its Long Beach assembly line.

The fate of the 717 seemed all but sealed when it became apparent a bulk order for 100-seat jets from four Star Alliance members wouldn’t materialize. Air Canada broke from the group first, opting instead for a mix of Embraer 190s and Bombardier CRJs, while Austrian Airlines began taking ex-American Airlines Fokker 100s it plans to fly until at least 2008.

Although budget airline AirTran found reasonable success with the updated DC-9–inherited with Boeing’s acquisition of McDonnell Douglas in 2000–the 717’s lack of siblings and the existence of the similarly sized Boeing 737-700 seemed to doom it from the start.

“The problem with the 717 is that it doesn’t have all the latest technology, it doesn’t have the range and it doesn’t have a family,” concluded former Boeing executive and Bombardier C Series project leader Gary Scott.