Flight Data RecorderNavigation — Instrumentation — DGCA CPL practice questions

All 6 questions — Flight Data Recorder

Navigation — Instrumentation · DGCA CPL. The correct option is marked on each.

1. Q1. The primary function of the Flight Data Recorder (FDR) is to:

   • A.Monitor engine trend data and assist in planned maintenance
   • B.Preserve aircraft data to determine the cause of an aircraft accident✓
   • C.Transmit real-time data to ground stations via ACARS
   • D.Record cockpit voice communications and ambient sound

   Why: The main function of the flight data recorder is to preserve aircraft data so that the cause of an accident can be determined. Trend monitoring and troubleshooting are secondary uses, which is why the maintenance option is a common trap.

2. Q2. What is the minimum recording time for an FDR fitted to a turbine-powered aeroplane with an MTOM of 6,500 kg, registered in 1995?

   • A.10 hours
   • B.2 hours
   • C.25 hours✓
   • D.30 minutes

   Why: This aircraft is 6,500 kg MTOM — above the 5,700 kg threshold. For aircraft above 5,700 kg MTOM, the minimum recording time is 25 hours . The registration date (1995 = after 1 June 1990) places it in Case 2. See Section 6 . — Always check MTOM first. Above 5,700 kg = 25 hours. Below 5,700 kg (turbine, >9 seats, post-April 1998) = 10 hours. These are the only two FDR recording time thresholds.

3. Q3. An FDR is found unserviceable before flight. Under which conditions may the aircraft be dispatched without a serviceable FDR?

   • A.If the CVR is operative, within 8 consecutive flights, and within 72 hours of discovering the unserviceability✓
   • B.If both FDR and CVR are inoperative, within 10 flights, and within 48 hours
   • C.At captain's discretion, provided the flight is under 1 hour in duration
   • D.Only with specific authority from the regulatory authority for each individual flight

   Why: The regulations allow dispatch with an inoperative FDR provided: (1) it is not reasonably practicable to repair before flight, (2) no more than 8 further consecutive flights , (3) not more than 72 hours since the unserviceability, and (4) the CVR is operative. All four conditions must be met. See Section 7 . — Remember: 8 flights and 72 hours — the same limits apply to CVR dispatch with an unserviceable CVR. The logic is: if FDR is u/s, the CVR must be serviceable to still capture some record of events.

4. Q4. An aircraft with MTOM of 35,000 kg must record which of the following sets of parameters on its FDR?

   • A.Main parameters only (time, attitude, airspeed, pressure altitude, heading, etc.)
   • B.Main parameters plus additional parameters (flight controls, radio altitude, cockpit warnings, landing gear)✓
   • C.Cockpit voice communications and aural environment only
   • D.Engine parameters and fuel flow only, as it is above 27,000 kg

   Why: Aircraft with MTOM above 27,000 kg must record both the main mandatory parameters AND the additional parameters (positions of primary flight controls and trim, radio altitude and navigation info displayed to crew, cockpit warnings, and landing gear position). At 35,000 kg this aircraft clearly exceeds the 27,000 kg threshold. See Section 5 and Section 6 . — The two MTOM thresholds to memorise: > 5,700 kg = FDR required, 25-hour recording; > 27,000 kg = additional parameters also required.

5. Q5. When must the FDR automatically stop recording?

   • A.Immediately when the last engine is shut down
   • B.When the aircraft's weight-on-wheels switch activates on landing
   • C.5 minutes after the last engine is shut down✓
   • D.When the parking brake is set and all engines are stopped

   Why: The regulation states the FDR must stop automatically after the aircraft is incapable of moving under its own power. In practice, this is achieved by automatically switching off 5 minutes after the last engine is shut down. This 5-minute buffer ensures post-shutdown data is captured. See Section 7 . — The 5-minute stop delay appears in both FDR and CVR regulations. This is the same delay referenced in the GND CTL AUTO switch logic. Consistent value — easy to remember.

6. Q6. The EVENT push-button on the FDR pedestal control unit serves to:

   • A.Erase the last 30 seconds of FDR data in an emergency
   • B.Activate the underwater locating device
   • C.Place a bookmark/event mark on the FDR recording to aid subsequent analysis✓
   • D.Switch the FDR from automatic to manual recording mode

   Why: The EVENT push-button "sets an event mark on the DFDR recording. This acts as a kind of bookmark to enable the 'event' to be found rapidly on the recording at a subsequent analysis." See Section 3 . — The EVENT button is a crew-annotation tool — it does not erase, trigger, or alter recordings. It simply flags a point in time for investigators or analysts to examine.