groundspeed and glidescope


Well-Known Member
Hey Guys, I need some help answering this question:

Explain how your grounspeed must be adjusted to remain on the glidescope?
A rule ot thumb to figure out a descent rate based on groundspeed to get a three degree glidepath is to take you groundspeed, deivide it by two and add zero.

ie.. 100 knot groundspeed/2=50, add a zero to get 500 and this would give you an approximate 3 degree glidepath if you flew 500 fpm descent.
As your groundspeed increases, your descent rate must also increase to stay on the glide slope. And vice versa.
Since a glideslope is a ground based instrument, your VSI will remain the same if your ground speed remains the same. But, as you know, we fly an airplane using its airspeed, and depending on the wind, the groundspeed changes. Threfore, your VSI changes also.
As stated above, headwind reduces your VSI, tailwind increases it.