FTA Completes Citation Re-engining Flight Tests

On October 16, Mojave's Flight Test Associates (FTA) completed a Cessna Citation re-engining flight test program for Clifford Development Group. Clifford is acquiring FAA Supplemental Type Certificates to re-engine Cessna Citation II and SII business jets with Williams FJ44-3A engines, replacing the aircraft’s original Pratt & Whitney JT-15 turbofans. The flight test program contract was originally awarded to FTA in March, 2007.

According to Bruce Wilcox, Chief Operations Officer for Clifford, installation of the FJ44s results in a thrust increase of 300 pounds and up to a 27% fuel burn reduction. The re-engining package rebuilds and strengthens the engine pylon structure and replaces Cessna’s original engine control cables with a FADEC system. The new engines allow the aircraft to be certified to Stage 4 noise criteria.

Flight Test Associates was selected by Clifford to perform the flight test data collection and analysis required by the FAA for STC approval. The testing involved two aircraft, a Model 550 Citation II and a Model S550 Citation II/S, which together flew about 80 flight hours, according to FTA's John Ligon. FTA developed and installed the digital data acquisition systems, which interfaced with the engines' FADEC system, and fed flight performance data to a laptop computer on board.

Great Lakes Aviation of Kalamazoo, Michigan, will perform the conversions, and with the awarding of the FAA STC imminent, work has already begun on the first customer’s aircraft. Dan Buzz of Great Lakes stated that there is a potential market for over 800 conversions.

FTA's website

Clifford Development Group's website

Great Lakes Aviation website