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Old 16th Apr 2017, 16:32
  #1077 (permalink)  
gulliBell
 
Join Date: May 2002
Location: Wanaka, NZ
Posts: 2,132
Originally Posted by agirl View Post
..The landing gear was down at the time of the accident.
In mode 4B, if the landing gear was down at the time of the accident, below 120kts, the aural warning at time stamp 2.03.09.026 on the CVR should have been "TOO LOW TERRAIN". The aural warning actually recorded at that time was 'TOO LOW GEAR", which means the gear was up. If the gear was up then the system couldn't have been in mode 4B, it would be in mode 4A. The standard boundary for mode 4A is at 150' RA. That's my understanding of reading the manual.

The report says low altitude switch was engaged. This is what the manual says about that:

"A LOW ALT switch allows for helicopter operations that require low altitude flight. Use this function for
flight at low altitude in VFR conditions. Engaging this function:
ƒƒ Inhibits Mode 1
ƒƒ Significantly reduces Mode 2 warning boundaries
ƒƒ Significantly reduces Mode 4 warning boundaries
ƒƒ Enables Mode 6 “Altitude-Altitude” call-out
ƒƒ Reduces Terrain Advisory look ahead distance
Low Altitude operation is defined as operation below 500 ft AGL, in a high-density metropolitan environment
with high-rise buildings, below 1,250 ft AGL when the GPS is not operational or is providing poor accuracy,
or airport maneuvering where airspeeds exceed 50 Kts"

Last edited by gulliBell; 16th Apr 2017 at 16:49.
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