Citation modification specialist Sierra Industries of Uvalde, Texas, has received an STC for its Stallion conversion, a Citation 500/501 powered by Williams FJ44-2A turbofans in place of the twinjet’s original Pratt & Whitney Canada JT15Ds.
Sierra CEO Mark Huffstutler said the Stallion will climb directly to FL430 “at any weight or temperature and cruise at 380 knots on 620 pounds per hour of fuel for more than 1,400 nautical miles.”

The FJ44-2A turbofans feature electronic engine controls that “virtually eliminate any engine-management issues,” according to Huffstutler. These controls automatically determine the proper power setting from the conditions present and set the maximum power for those conditions.

Said Huffstutler, “Push the throttles to the stop for takeoff and never touch them again until descent.”

Conversion price is about $1.47 million and downtime is about 10 weeks. Sierra’s Eagle II conversion will add 730 pounds of fuel capacity to the Stallion to provide a range of up to 1,750 nm, but specific fuel consumption will be greater than for just a Stallion conversion.

Some 30 Sierra Eagle II Citation conversions have been completed, Sierra manager of marketing and sales Don Smith said. “We have two funded orders for Stallions,” he said. In addition to the aircraft used to obtain the STC, a second will be completed this month. Sierra has brought its Stallion to the NBAA Convention for display on the static line at Orlando Executive Airport.