Nav Aids 10

  1. What is the basic function of TAWS?
    To alert flight crew if their A/C is in immiment danger of flying into the ground or an obstacle.
  2. What is the basic principal of operation of the first generation GPWS?
    GPWS computes the A/Cs closure rate with terrain, and then compares that result with acceptable values that have been pre-programmed
  3. What is the major limitation of the first generation of GPWS?
    only gathers data from directly below the A/C. no acurate future predictions.
  4. What is the basic principal of enhanced GPWS?
    EGPWS compares current GNSS data with a global database, to warn of possible impacts.
  5. Below what altitude do radio altitude (RA) based GPWS alerts become active?
  6. What protection is offered by TAWS modes 1,3,5, and 7 respectively?
    • Excessive baromatric decent rate.
    • Altitude Loss after takeoff and Go around
    • Decent below glide slope
    • Reactive windshear warning (RWS)
  7. What are the two addition protection modes offered by EGPWS
    Terrain awareness and Alerting Display and Terrain Clearance Floor (TCF)
  8. What is the peaks mode Terrain Display?
    Enhancement of EGPWS terrain display which allows terrain below the A/C to be viewed on the EHSI/ND during cruise.
  9. What protection is offered by TAWS Terrain Clearance Floor (TCF)
    Unsafe terrain clearance when in the landing config.
  10. What minimum system inputs are required to provide EGPWS Mode 1 to Mode 5 (inclusive) alerts and warnings?
    Radio altimeter, air data computer, flap and landing gear position, and the ILS reciever.
  11. What mode does the GPWS alert "sink Rate" apply to?
    Mode 1 - Excessive sink rate.
  12. What alerts are issued if the TAWS Mode 1 warning area is penetrated?
    The aural alert becomes "Pull Up" accompanied by whoop whoop, and the master WARNING and PULL UP lights illuminate.
  13. What is the initial aural warning for an EGPWS mode 2A alert, which warns of an excessive terrain closure rate at low airspeed and NOT in the landing configuration?
    "TERRAIN TERRAIN" repeated twice.
  14. When does the the EGPWS mode 2A alert "Terrain Terrain" occur?
    Above 1650 feet radio alt at less than 190kts, with excessive terrain closure rate, and with flaps not in the landing configuration.
  15. which mode does the GPWS alert "sink rate" apply to?
    Mode 3 - Altitude loss after Takeoff or Go Around
  16. What TAWS alerts will be issued if the airspeed is close to landing speed, and the gear is not down below about 500ft RA?
    "TOO LOW-GEAR" and is accompanied by the GND PROX light.
  17. What alerts are issued if the TAWS mode 4 warning area is penetrated?
    An aural alert of "TOO LOW-TERRAIN". The GND PROX warning light remains, and PULL UP displays on the PFD.
  18. When does the loud (normal or hard) EGPWS mode 5 aural alert "glideslope" occur?
    Between about 300ft and 50ft radio altitude, when glideslope deviation exceeds half scale deflection (two dots) below.
  19. when does the EGPWS mode 6 aural alert "Minimum" occur?
    When the A/C is below a pilot set radio minimum Alt
  20. What aural alert is issued if the EGPWS TCF is penetrated? and then if decent is continued?

  21. Where are TAWS terrain displays shown?
    On the EHSI or ND
  22. Can both the weather radar and the TAWS terrain display be shown on the EHSI/ND simultaneously?
    No not normally.
  23. Can both the TAWS terrain display and other displays such as ACAS, LNAV, routing etc, be shown on the EHSI/ND simultaneously?
Card Set
Nav Aids 10