Flight Director SystemsNavigation — Instrumentation — DGCA CPL practice questions
Question 1 of 6
The Flight Director System was originally developed as an aid for which phase of flight?
All 6 questions — Flight Director Systems
Navigation — Instrumentation · DGCA CPL. The correct option is marked on each.
Q1. The Flight Director System was originally developed as an aid for which phase of flight?
- A.Cruise navigation
- B.Landing✓
- C.Take-off roll
- D.Engine-out climb
Why: The FDS was originally developed as an aid to the pilot during landing. It provides steering and attitude signals on one instrument to reduce workload during the approach. See Section 1 . — The evolution from a landing aid to a full-flight FDS integrated with autopilot is important context for understanding its architecture.
Q2. What is the key difference between "raw" and "computed" information in an FDS?
- A.Raw information comes from the IRS; computed information comes from the FMC
- B.Raw information shows current deviation; computed information uses rate of change to anticipate corrections✓
- C.Raw information is used only for autopilot; computed information is for the pilot only
- D.Computed information requires ground station input; raw information does not
Why: Raw information is unprocessed data (e.g., ILS deviation in degrees) — it shows how far off track you are. Computed information is derived from the rate of change of deviation, allowing the FDS to anticipate turns/climbs/descents for smooth interception of the track. If the FDS fails, raw info may still be available. See Section 4 . — On FDC failure, tell your students to use the raw GS/LOC needles — they still work independently of the FDC.
Q3. On an EFIS FMA, how are engaged modes displayed compared to armed modes?
- A.Engaged modes — amber, second line; Armed modes — green, top line
- B.Engaged modes — green, top line; Armed modes — white, second line✓
- C.Engaged modes — white, top line; Armed modes — blue, second line
- D.Both engaged and armed modes are shown in green; armed modes are boxed
Why: On an EFIS FMA, engaged modes are shown on the top line in green, while armed modes are on the line below in white. Newly changed information is boxed for emphasis. See Section 3 . — Green = active/working RIGHT NOW. White = standby/waiting to capture. This convention is standard across Boeing and most modern aircraft.
Q4. During a Boeing 737-400 take-off with FD engaged, what pitch command is given when IAS reaches 60 knots?
- A.10° nose-up
- B.15° nose-down
- C.15° nose-up✓
- D.5° nose-up, wings level
Why: Initially the FD commands 10° nose-down pitch and wings level. At 60 kt IAS, the FD command changes to 15° nose-up and wings level. See Section 8 . — Remember the sequence: 10° ND (initial) → 15° NP (at 60 kt) → then pitch to maintain MCP speed +20 kt after achieving climb rate.
Q5. Why is Radio Altimeter-based gain scheduling considered superior to time-based or marker beacon-based methods?
- A.It is cheaper to install and maintain
- B.It provides continuous, gradual scheduling based on actual aircraft height without requiring ground infrastructure✓
- C.It removes the need for an ILS entirely
- D.It is required by ICAO for all Category 1 approaches
Why: RA-based gain scheduling is continuous and gradual (vs. stepped), relies on no ground signals (unlike marker beacons, now removed from many airfields), and directly correlates with actual aircraft height above ground — the most operationally relevant parameter. See Section 10 . — The fact that marker beacons have been removed from many airfields makes marker-based gain scheduling increasingly obsolete.
Q6. The FD Comparator removes command bars when the pitch difference between the two FDS is approximately:
- A.5–10°
- B.10–15°
- C.1–4°✓
- D.½–1°
Why: The FD Comparator monitors command bar positions and removes bars when a difference of approximately 1–4° of pitch and/or 3–9° of roll is sensed between the two FDS. See Section 11 . — The comparator only operates in TOGA or APP mode below 800 ft RA — exactly when precision matters most.