First flight of a Williams FJ44-2C-powered Learjet 25D continues to be a moving target as Guthrie, Okla.-based Spirit Wing awaits delivery of the engine nacelles from Nordam. The design of the stainless steel inlets is made more complex by the fact that they must act as radiators to dissipate the 800-deg F heat of the FJ44’s bleed air, which will provide full-time anti-ice protection to the engines. “We expect to receive the nacelles in November,” Calvin Burgess, president and owner of Spirit Wing told AIN. First flight will take place as soon as the nacelles can be mounted and ground runs completed. Certification continues to move aft as well, but may still be possible in the spring, according to Burgess.