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What is service volume of ILS?

Yank McCobb

Song and Dance Man
Joined
Mar 10, 2005
Posts
538
Total Time
18000
From the AIM 1-1-9

"The localizer provides course guidance throughout the descent path to the runway threshold from a distance of 18 NM from the antenna between an altitude of 1000 ft above the highest terrain along the course line and 4500 ft above the elevation of the antenna height.

To 10 degrees either side of the course along a radius of 18 NM from the antenna; and

From 10 to 35 degrees either side of the course along a radius of 10 NM."

"The glide path projection angle is normally adjusted to 3 degrees above horizontal so that it intersects the MM at about 200 feet and the OM at about 1400 feet above the runway elevation. The glide slope is normally usable to the distance of 10 NM. However, at some locations, the glide slope has been certified for an extended service volume which exceeds 10 NM."
 

Mickey

Well-known member
Joined
Jan 5, 2002
Posts
210
Total Time
12000+
It's a great question. I get FO's trying to ID the ILS way too far out and they can't figure why they don't get a good signal.


LOC coverage +/- 35 degrees=10nm +/-10 degrees=18nm
take care
 

Workin'Stiff

Fire in 'da hole!!!!
Joined
Sep 10, 2004
Posts
775
Total Time
Lots..
haha... Well, that is the correct terminology for the question he was asking...
 
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