Problems affecting manufacture of the all-composite airframe of the Learjet 85 has prompted Bombardier to delay entry into service to the third quarter of 2014.
The airframer's top executives are unwilling to say unspecified problems have been completely overcome, even as the first flight-test vehicle advances in final assembly in Wichita, Kansas.
"I don't want to say the challenges are completely behind us," says Pierre Beaudoin, Bombardier president and chief executive. "There will be additional challenges, but I think we understand very well the work that needs to be done."
The Learjet 85's all-composite fuselage structure is a first for Bombardier in several ways - in addition to the usage of the material itself, it is also the first time Bombardier has assembled complete airframe structures in Querétaro, Mexico.
A new workforce has been hired and trained at the facility on Mexico's high central plateau, where the roughly 6,000ft (1,830m) elevation requires Bombardier to use special techniques in the curing process for the composite material.
However, progress continues on preparing FTV-1 for first flight later this year. In September, the programme had shipped the fuselage for FTV-1 from Querétaro to Wichita, but the wings were not scheduled to ship to Wichita until November.
According to a Bombardier video posted online on 22 February, the wings and landing gear have been installed on FTV-1, but the Pratt & Whitney Canada PW307B turbofan engines have yet to be mated to the aircraft, nor has Bombardier installed the doors and windows.
FTV-1 has now moved into the second assembly positions, where Bombardier is installing the first systems. FTV-1 has reached the "power on" milestone, says Ralph Acs, Learjet vice-president and general manager.
The scheduling delay for entry into service has not changed Bombardier's outlook for the midsize business jet, which will face competition in two years from the shorter-range but larger-cabin Embraer Legacy 450.
Meanwhile, the company plans to introduce the Learjet 70/75 into service in the first half of 2013, hoping to boost sales for the struggling light jet sector as Learjet 40/45 production is phased out.
[Correction: Original article incorrectly stated customers had cancelled orders for 17 Learjet 85s. That figure represents the total number of order cancellations in 2012 for all Bombardier business jets.]