Less than 11 months after first flight and a year and a half of
design, engineering and test flights, the FAA has awarded Sierra
Industries, Ltd. STC ST09559AC Approved Model Listing (AML) for
their Citation 550-based Sierra Super II modification.
The Sierra Super II modification upgrades the Citation
II’s performance by re-powering the aircraft with Williams
International’s FADEC-controlled 2820 lb. thrust FJ44-3A
engines. Williams’ high-performance FJ44-series turbofan
engines are currently utilized on more than 20 different business
jet designs. Sierra Industries is the ONLY non-OEM company to
receive FAA certification to install Williams engines on a
certificated aircraft, with a current offering of 6 different
models of FJ44-powered aircraft.
As of this writing, the company has 6 Sierra Super II aircraft
in current production at its facilities in Uvalde, Texas, with an
order book stretching well into 2009. Sierra’s test pilots
flew the aircraft the equivalent of some 1-1/2 times around the
globe, verifying the Sierra Super II’s performance and
reliability. During 87 test flights totaling 123 hours of flying
time, the Super II test aircraft achieved its projected top speed
of 404 KTAS and demonstrated altitude performance at 50,000 feet.
The Super II STC includes all the latest FAR amendments and is
fully Stage IV noise compliant.
The Super II provides an 'across-the-board' performance
enhancement for the Citation II – boosting fuel efficiency
and reducing carbon emissions by as much as 27%, cutting
time-to-climb to under 25 minutes to FL430, extending range to
nearly 1800 NM, and increasing maximum fuel payload. Dramatic
reductions in takeoff field length (more than 20% reduction at 5000
ft., ISA +20º), coupled with increased climb rates make the
Super II a superb all-around performer for virtually any field
conditions or altitude. Dual Channel FADEC controls provide smooth,
vibration-free flight for passengers and a reduced workload for the
Building on Sierra’s 25 years of Citation modification
history and 15 years of experience in Citation re-engining, the
Super II development program has been leveraged on the FAA and
EASA-approved Eagle II and Stallion modifications, which also
feature Williams International FJ44 advanced turbofan engines. The
Super II modification extends Sierra’s history of producing
more than 40 FJ44 re-engined Citations since 2002.
Sierra Industries has specialized in Citation aircraft for
nearly 30 years and holds more than 75 proprietary Citation
modifications and company total of 300 FAA STCs. Sierra is a wholly
owned subsidiary of The SkyWay Group, Inc., which owns a business
portfolio of six aviation related companies, including FlighTime
Business Jets and the Uvalde Flight Center.
Next; Sierra’s newest re-engining program involves adding
the 2820 lb. thrust Williams FJ44-3A engines to the Cessna S550
Citation S-II model. With its supercritical wing design, the
FJ44-powered Sierra Super S-II promises improvements in
across-the-board performance. The Super S-II program is well
underway with FAA approval expected to follow shortly after the
Super II STC.