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Old 16th Apr 2017, 08:21
  #1048 (permalink)  
Mark Six
 
Join Date: Aug 2000
Location: Asia/Oz
Posts: 219
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Gullibell, the aircraft I fly has much the same equipment and avionics as the R116, including the exact same model of EGPWS. Descent below the preset RADALT height (in this case 180') will cause an "Altitude, Altitude" warning from the RADALT. There is no 'Altitude, Altitude" aural alert associated with the EGPWS. Some of the terrain associated alerts are "desensitised" when landing gear is lowered. The crew of R116 selected LOW ALT mode on the EGPWS. I don't know about R116 but in the A/C I fly it is only possible to display either the EGPWS page or the weather radar picture, not both on the same display. If your display is in weather mode and an EGPWS alert is triggered the display will automatically switch from weather to TAWS. Obviously you don't want to suddenly lose your radar picture at a vital stage of a rig approach or when using radar for weather/terrain avoidance so LOW ALT is enabled to reduce the threshold for EGPWS warnings. It seems counter intuitive to desensitise your EGPWS when flying at low altitude but that is often what is called for.
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