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  #39  
Old October 5th 03, 12:39 AM
Fred E. Pate
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Roger Halstead wrote:

It seems a bit strange...
.
DH on the ILS at MBS is only 200 feet AGL and that is with no
temperature correction. In the winter we regularly see below zero
F and it's not rare to see it at minus 20 at night


Yup, but temperature doesn't effect the glideslope, just where you put
the MAP along that glideslope. On the so-called "Baro-VNAV" approaches,
the glideslope is defined using barometric altimeter data, so the entire
glideslope will be shallower and closer to the ground on a cold day.
And if there is a low-level temperature inversion the glideslope won't
even be a straight line.