peter manktelow
15th Nov 2003, 05:14
Please take a look at page 46 "Rotor and Wing" (Oct 2003) article by Mott F. Stanchfield.
Scary if true but am just a little sceptical.
In the article he relates flying a 206 with a newly fitted RADALT and descending at night over water with 200 feet bugged!!! He passes 200' without the warning light illuminating.
I quote
" The problem was the surface being absolutely flat and calm , the radar signal penetrated it and was trying to read the deep ocean bottom. The radar altimeter worked well over land but for good reason , I never trusted it over water again"
end quote
I have heard of and experienced , doppler unlock over smooth glassy water but never radalt. (Now lets not get into the issue of overwater night flying and who should , or should not , be down that low at night. ) What concerns me is that I must rely 150% on my radalt for the Rig Radar approach (ARA/NDB) during the day let alone at night.
Is Mr Stanchfield the victim of a faulty radalt or misconception of how the system works ????
Over to you dear reader
:8
Scary if true but am just a little sceptical.
In the article he relates flying a 206 with a newly fitted RADALT and descending at night over water with 200 feet bugged!!! He passes 200' without the warning light illuminating.
I quote
" The problem was the surface being absolutely flat and calm , the radar signal penetrated it and was trying to read the deep ocean bottom. The radar altimeter worked well over land but for good reason , I never trusted it over water again"
end quote
I have heard of and experienced , doppler unlock over smooth glassy water but never radalt. (Now lets not get into the issue of overwater night flying and who should , or should not , be down that low at night. ) What concerns me is that I must rely 150% on my radalt for the Rig Radar approach (ARA/NDB) during the day let alone at night.
Is Mr Stanchfield the victim of a faulty radalt or misconception of how the system works ????
Over to you dear reader
:8