ICING AND TURBULENCE CHANGE MORE THAN A SWITCH POSITION
The clean-airframe assumption is fundamental to the performance being used. The FCTM explains how ice changes the wing's lift and drag characteristics and why cold-soaked surfaces can require attention even when outside air temperature alone appears reassuring. Inspect the relevant surfaces and apply the applicable ground de-icing/anti-icing procedure when required. Aircraft anti-ice systems and a ground treatment have different jobs. A visually clear windshield or a selected engine anti-ice switch does not establish the condition of the entire airframe. [21, PDF pp. 277–281]
Ground treatment introduces its own sequence and time-dependent assumptions. Record the actual treatment information and use the applicable current holdover guidance and inspection requirements rather than taking a value from an old example. Consider the effect of taxi, precipitation and a takeoff delay on that assessment. The source also connects contamination with flap/slat and ground-handling considerations. Restore the aircraft from any treatment configuration using its procedure, then reconcile performance and physical configuration before departure. A completed service animation does not independently prove that every operational treatment condition has been simulated. [21, PDF pp. 278–283] [133, Documented integration limitations and service workflow]
In flight, apply the installed aircraft's anti-ice procedure for the conditions and monitor the corresponding supplies and indications. Include its performance consequences in takeoff or subsequent assessments. Detection equipment, when fitted, is an additional source of information; its presence does not make every protected area or every icing case identical. Fenix documents an optional ice-detection installation. This establishes a configuration feature, not verification of every atmospheric accretion or alert condition. Preserve that distinction when comparing two liveries that show different equipment or messages. [77, Ice/rain protection: system scope and controls] [21, PDF pp. 279–281] [70, fnx_ice_detection_enabled option]
For turbulence, anticipate the conditions from weather information and prepare the cabin before the encounter. Use the applicable penetration guidance and avoid overcontrolling. The source distinguishes moderate and severe cases, with different thrust/autothrust considerations; its particular speeds and settings must be taken from the applicable reference. Monitor margins at the current level and the actual mode/engagement state after a disturbance. A previous normal-law demonstration does not establish that every protection or automation function remains available after a concurrent sensor or system failure. [21, PDF pp. 283–285] [21, PDF pp. 255–260]
Keep a turbulence or icing scenario narrow enough to interpret. Record aircraft configuration, weather source, level, speed, relevant protections and any deliberate failure. Repeat from the same state before changing another variable. In an online flight, make the required path or delay decisions through the applicable ATC interaction; in an isolated lesson, use a planned exercise boundary and debrief the result. The useful question is which assumption changed and what consequence followed. A dramatic visual effect or large joystick movement is not a measurement of simulation fidelity. [21, PDF pp. 277–289] [127, Manual scenarios and observed failure state]