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Autopilot Use in IFR

Objective​

Understand and apply the different autopilot modes, how the autopilot operates, and how it's effective use in an IFR environment.

Timing​

30 minutes

Format​

Overview​

  • Effective use of the autopilot
  • Autopilot Documents
  • Mode Annunciations
  • Lateral Modes
  • Vertical Modes
  • Approach Modes
  • Specific scenarios
    • How to use VNAV Mode
    • Fully-Coupled Go-Around

Elements​

Effective Use of the Autopilot​

  • Workload reduction.
  • Allows you to focus your attention elsewhere (ATC, briefing and approach, programming avionics, dealing with passengers).
  • Spatial disorientation mitigation via LVL button.

Autopilot Documents​

  • Retrofit autopilots are installed per an STC.
  • GFC 500 Pilot's Guide.
  • GFC 500 AFMS (must be in the plane).

Panel diagram​

  • alt text

Mode Annunciations​

  • Green indicates an active mode.
  • White indicates an armed mode.

Initial Mode Activation​

  • Illustrations of initial mode activation cues.

Lateral Modes​

  • Refer to AFM

Vertical Modes​

  • Refer to AFM

Approach Modes​

  • APR follows glideslope and localizer, capturing glideslope only from below.
  • NAV mode can be used for approaches without vertical guidance.

How to Use VNAV Mode​

  • Ensure altitudes are configured on the GTN.
  • Ensure CDI is in GPS mode.
  • Set altitude preselect to the clearance limit.
  • Press VNAV to arm (white VNAV annunciation).
  • Expect the "Vertical Track" alert one minute before top of descent.
  • Intermediate level-offs present with ALTV annunciation.
  • VNAV will not capture a descending profile unless the selected altitude is valid and at least 75 feet below current altitude.

Fully-Coupled Go-Around​

  • Set missed approach altitude in the preselect.
  • At the go-around point, press the GA switch twice to engage G/A (7° pitch-up, wings level).
  • Transition to IAS or VS to meet missed approach altitudes.
  • Transition to NAV or HDG to track the missed procedure.

Summary​

  • Use the autopilot to shed workload in a busy cockpit.
  • Guard against mode confusion, especially PIT and ROL modes.
  • VNAV requires the altitude bug set below current altitude at the final target altitude.
  • Glideslopes only capture from below.
  • G/A mode commands 7° nose-up with ALT mode armed.

References​