User manual

DodoSim 206 FSX User Manual
Copyright© 2009 DodoSim. All Rights Reserved.
Page 3
Flight Dynamics:
 More authentic handling: The helicopter exhibits a pendulum tendency at low airspeeds due
to the interaction of the fuselage mass and the rotor system and a slight instability in the hover
means that the pilot must constantly work with the controls to hold a steady position.
 Torque-Induced Yaw: The pilot must counter the tendency of the transmission to turn the
aircraft in opposition to the rotors at low airspeeds using the anti-torque, (rudder), pedals.
 Transverse Flow Effect: The pilot must counter the tendency of the helicopter to pitch up and
to the right as it accelerates from the hover into forward, (or any directional), flight.
 Flap Back: The pilot must counter the tendency of the nose to try and pitch up as forward
airspeed increases.
 Translating Tendency: The pilot needs to oppose the helicopter’s tendency to try and slide
right in the hover with a left cyclic input.
 Dis-symmetry of Lift: The pilot must counter the greater lift generated by the advancing blade
in forward flight with right cyclic, (stick), control.
 Induced Flow Rotor RPM modulation: The pilot must use collective pitch and helicopter
attitude to manage the rotor RPM, which can rise or fall depending on the angle and strength of
the airflow through it.
 Rotor Droop: The pilot must make smooth and careful collective pitch changes to avoid
overloading the engine output and loosing rotor RPM.
 Vortex Ring State: The pilot must ensure that descents are performed that do not allow the
helicopter to recycle its own down-wash and accelerate its descent uncontrollably.
 Loss of Tail Rotor Effectiveness: The pilot must manage low speed turns carefully in windy
conditions where the vortices from the main rotor or wind strength alone can reduce the ability
of the tail rotor to maintain the heading or perform a turn. Extra care is needed to prevent
violent “weather-vaning” in a strong tail wind.
 Retreating Blade Stall: Exceeding maximum speed, (dependent on gross weight and altitude),
will cause the helicopter to pitch and roll as lift is lost from the retreating blade.
 Tail wind effect on Horizontal Stabiliser: - Tail winds at very low speeds or hover may lift the
tail’s horizontal stabiliser, requiring forward cyclic input to compensate.
Fuel Control and Engine Management:
 Engine start up and shut down procedures: The package includes helicopters with either
CECO or Bendix Fuel Control Unit systems, requiring the pilot to manage the fuelling during the
start procedure differently to ensure a safe start and avoid a “hot start” or engine melt-down.
 Idle-Release latch: An idle-release latch is fitted to the simulation of the twist-grip throttle,
which prevents the fuel flow from being completely stopped if the throttle is inadvertently closed.
 Fuel Pumps and loss of fuel pressure: Fuel pumps are required to be used to retain fuel
pressure at high altitudes or low fuel levels to prevent an engine flame-out due to loss of fuel
pressure.
 Fuel Filter contamination: The fuel filter degrades over time as fuel passes through it and is
eventually bypassed, leading to higher engine exhaust gas temperatures and an increase in
wear as unfiltered fuel is burnt.