Throws and CG
The CG and throw recommendations in this
manual were based upon limited test flying.
Please check with the manufacturer for current
information before flying your SU-27 for the first
time.
For the first flight, set the CG at approximately
8.5 inches aft of the wing/fuse junction at the
leading edge, measured aft along the wing/fuse
joint. For an easy method of precisely calculating
CG on large aircraft such as the SU-27, visit the
Jet Pilots Organization website
and access the weight and balance spreadsheets
under the “members” tab. You will find
instructions on how to use the spreadsheets there,
as well as the data used to balance the prototype
FB SU-27. You will need to fine tune the CG as
you fly the aircraft based upon your fuel tank
configuration and personal tastes, so keep this in
mind as you install any ballast.
Measure the CG with residual fuel and the gear
lowered.
Maximum throw on the elevons measured at the
leading edge is 40 mm for elevator function, with
30 mm for aileron throw. Set as much rudder
travel as you can without binding.
It is important that you set three rates for
elevator and aileron, using the recommended
throws as the mid position, with settings higher
and lower. In this fashion, you can quickly set the
throw to your personal flying taste and habits on
the first flight. We used 40% exponential on the
first flights for both aileron and elevator.
For first flights, have the flaps on a slider control,
such that flaps can be incrementally deployed.
First Flights
• Do not attempt a first flight in adverse weather
conditions.
• Make sure there are no known issues with the
airplane before attempting the flight.
• Have a qualified spotter handy to help you with
trim and rate switches on the first flight.
Designate a third individual as a timekeeper.
• Leave the gear down on the first flight.
• Advance the throttles slowly but fully, and keep
the turns shallow at first.
• Focus first on trim and rate. Establish these on
the first few laps.
• Take the plane to a safe altitude and become
comfortable with slow speed handling. Carefully
deploy the flaps, looking for any loss of control in
roll or pitch as you do. If you experience any
issues in this regard, back off the flap setting
until the problem abates.
FB Su-27
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