The altitude at the marker is a double check on the
altimeter and the glide slope. If the altimeter is set
incorrectly or broken or if you have intercepted the wrong
glide slope lobe, the pilot has an opportunity to catch the
error and figure out what is wrong.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


wrote in message
oups.com...
| If the pilot uses the glideslope for backup vertical
guidance to give a
| smooth transition to the final segment (while using the
altimeter
| readout outside the FAF to ensure he doesn't descend
below 1800) then
| what's wrong with that?
|
| Nothing wrong with that.
|
| That isn't really correct either. There's no necessity
to monitor
| the altimeter at SCK because there's no step-down fixes or
other
| crossing restrictions at issue. Above 1800 feet on the
glideslope, the
| glideslope is advisory, but the pilot is perforce
satisfying the =1800
| foot minimum altitude requirement. Below 1800 feet the
glideslope
| becomes primary. So in practical terms nothing happens at
1800 feet.
| There's nothing to monitor. (OK. I know, you part 121
types have now
| reached a point where the weather can below minimums
without
| necessitating a miss.)
|
| At *Stockton* (the subject of the question), there is no
legal issue.
| At LAX on the Civet arrival, and other situations where
there are
| step-down altitudes on the localizer outside the PFAF,
there is a
| potential issue. The step down minima take precedence over
the GS
| altitude.
|