C-40 WEATHER RADAR/WINDSHEAR

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    What does the TFR button do?
    TFR (transfer) – transfers other radar display selections to related map
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    What does the WX/T button do?
    WX/T (turbulence) – shows weather radar returns and turbulence.

    Turbulence display is available on displays of 40 nm or less.
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    What does the MAP button do?
    MAP – shows ground returns at selected gain level
  4. When is turbulence displayed?
    Turbulence display is available on displays of 40 nm or less.

    Note: Turbulence detection requires presence of detectable precipitation.

    Clear air turbulence cannot be detected by radar.
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    What does the IDNT button do?
    IDNT – suppresses ground return in WX and WX/T modes
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    What does the TEST button do?
    -tests weather radar system operation without transmitting

    -shows test pattern and any fault messages on navigation display MAP, center MAP, VOR, and APP modes, with WXR selected.

    Note: If the airplane is on the ground and the thrust levers are not advanced for takeoff, WXR tests the predictive windshear system (PWS) indications. These include PWS caution, PWS FAIL, and PWS warning. Deactivating WXR on the EFIS control panel will discontinue the test. The PWS test lasts approximately 15 seconds.
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    What does #2 indicate?
    Illuminated – related gain control is in an uncalibrated position.
  8. Below what altitude does the weather radar provide predictive windshear alerting?
    The weather radar also provides predictive windshear alerting below 1,200 feet RA.
  9. When are windshear warning and cautions available on takeoff and landing?
    Takeoff:  Warnings and Cautions are enabled from the beginning of the takeoff roll (0 knots) until the aircraft reaches 80 knots. From 80 knots until the aircraft passes 400 ft, only Warnings are enabled. From 400 ft through 1200 ft, Warnings and Cautions are enabled. All new alerts are disabled from the time the aircraft passes 100 knots until it reaches 50 ft.

    Landing:  Windshear detection is always activated when the aircraft is below 2300 ft in the takeoff and landing environment even when the radar is turned off. Warnings and Cautions are enabled from the time the aircraft passes 1200 ft until 400 ft. From 400 ft until 50 ft, only Warnings are enabled. From 50 ft until touchdown (0 ft), all new alerts are disabled.
  10. When does the weather radar automatically begin scanning for windshear?
    -thrust levers set for takeoff, even if engine is off or IRS not aligned, or

    -in flight below 2,300 feet RA (predictive windshear alerts are issued below 1,200 feet RA).

    Alerts are available approximately 12 seconds after the weather radar begins scanning for windshear. Predictive windshear alerts can be enabled prior to takeoff by pushing the EFIS control panel WXR switch. When PWS is enabled, radar antenna scan sweep is reduced.
  11. What are the indications of a windshear warning?
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  12. What are the indications of predictive windshear on takeoff and landing?
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  13. What does a predictive windshear symbol look like?
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  14. If there is potential for windshear on takeoff what can you do to Vr to mitigate risk?
    Consider increasing Vr speed to the performance limited gross weight rotation speed, not to exceed actual gross weight Vr + 20 knots. Set V speeds for the actual gross weight. Rotate at the adjusted (higher) rotation speed. This increased rotation speed results in an increased stall margin and meets takeoff performance requirements. If windshear is encountered at or beyond the actual gross weight Vr, do not attempt to accelerate to the increased Vr but rotate without hesitation (FCOM SP 17.28)
  15. What flap setting is recommended if there is potential for windshear on landing?
    Use flaps 30 for landing (FCOM SP 17.29)
  16. What are some actual windshear indications?
    The following are indications the airplane is in windshear:

    -windshear warning (two–tone siren followed by “WINDSHEAR, WINDSHEAR, WINDSHEAR”) or

    -unacceptable flight path deviations.

    Note: Unacceptable flight path deviations are recognized as uncontrolled changes from normal steady state flight conditions below 1000 feet AGL, in excess of any of the following:

    -15 knots indicated airspeed

    -500 fpm vertical speed

    -5° pitch attitude

    -1 dot displacement from the glideslope

    -unusual thrust lever position for a significant period of time.

    (QRH MAN 1.8)
  17. What is the windshear escape maneuver?
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  18. If windshear is encountered near the normal rotation speed and airspeed suddenly decreases, there may not be sufficient runway left to accelerate back to normal takeoff speed. If there is insufficient runway left to stop, initiate a normal rotation at least ___ before the end of the runway, even if airspeed is low.  Higher than normal attitudes may be needed to lift off in the remaining runway. Ensure maximum thrust is set.
    2000 feet
Author
CForty
ID
350341
Card Set
C-40 WEATHER RADAR/WINDSHEAR
Description
C-40 WEATHER RADAR/WINDSHEAR
Updated