Bombardier is pushing off the expected entry-into-service date for its Learjet 85 until summer 2014, citing “several new technology challenges” associated with the development of a composite aircraft.

The company had originally hoped to begin delivery of its largest and first all-composite Learjet before the end of 2013. But as the year began, the aircraft still had not flown, and Bombardier has not wanted to give a target for when the first flight might occur.

When asked if the delays were similar to those encountered with the company’s CSeries line of airliners, Bombardier President and CEO Pierre Beaudoin says that the delays stem from different causes. Bombardier had pointed to supplier issues with the CSeries, but with the Learjet 85 the delays come with the company’s most extensive use of composites in an aircraft, Beaudoin says. He notes, though, that all the other systems aboard the Learjet 85 are known systems that “we’ve done very well.”

Beaudoin says he believes the company has ironed out some of the challenges and now understands “the work that needs to be done” to bring an all-composite aircraft to market.

Bombardier originally had tapped Grob to supply composites for that airplane, but brought that work in-house after the company went insolvent.

Bombardier is nearing completion of the first flight test vehicle. The pressure fuselage and wing has been attached and landing gear installed. The company achieved electrical power-on to major harnesses in December, and the systems are being installed. The engines are also on site in Wichita, awaiting assembly.

Work has begun on other flight test vehicles, and Bombardier expects to send a complete aircraft structural test article shortly to the National Institute for Aerospace Research in Wichita for structural testing. As part of the aircraft certification work, the company plans to validate and certify the manufacturing process for the composite technology with the FAA, the company says.

Other work completed includes initial bird strike testing on the aircraft nose section and commissioning of all supplier “safety-of-flight” test rigs.

While Bombardier has not detailed orders for the aircraft, company executives maintain that the delay has not led to noticeable cancellations. Beaudoin says some cancellations may result when it comes time for milestone payments, but he expresses confidence that the company would be able to replace those orders – and at a stronger price.