A pilot engages the flight director (FD) for a VOR approach, and command bars appear on the PFD directing a descent and turn. The pilot hand-flies the airplane to follow the command bars, but the autopilot servos have not been engaged. Which statement correctly describes this situation?
- ASelecting an FD mode automatically engages the autopilot servos to fly the command bars
- BThe flight director cannot generate command bars unless the autopilot is engaged simultaneously
- CThe flight director provides visual pitch and roll guidance only; the autopilot must be separately engaged for the aircraft to be flown automatically
- DThe command bars only display the airplane's current attitude and provide no directive guidance
Show answer & explanationAnswer & explanation
Correct answer: C. The flight director provides visual pitch and roll guidance only; the autopilot must be separately engaged for the aircraft to be flown automatically
The flight director computes and displays pitch/roll guidance (command bars) independently of whether the autopilot servos are engaged; the pilot can hand-fly to the command bars, or separately engage the autopilot to have it fly those same commands automatically.
Why the other options are wrong
- A. Engaging an FD mode does not automatically engage the autopilot; separate pilot action is required to couple the autopilot.
- B. The flight director can and often does function independently, providing guidance for hand flying without the autopilot.
- D. Command bars are directive, showing where to move the controls, not just displaying current attitude like the miniature airplane symbol does.
Flight Director vs Autopilot Coupling
The flight director displays directive pitch/roll command bars that can be hand-flown or followed automatically by the autopilot once separately engaged; the two systems, though integrated, operate independently in terms of engagement.
- FD command bars show where to fly, not current attitude
- Autopilot servos must be separately engaged to fly the FD commands automatically
- FD can be used purely as a hand-flying aid
Memory trick: The FD is the 'coach' pointing the way; the autopilot is the 'player' that must be told to actually run.