Starlionblue From Greenland, joined Feb 2004, 16340 posts, RR: 66 Reply 7, posted (1 year 3 months 3 weeks 1 day 23 hours ago) and read 2519 times:
Quoting garnetpalmetto (Reply 6): these clearance ratios only apply to takeoffs or would they also apply to landings too?
They do since you have to account for go-arounds.
To answer your question, for the glide path you have to account for obstacles. However on landings you would have a fixed gradient (say 3%). If there's an obstacle in the way the threshold would be displaced forward along the runway until the glide path cleared the obstacle plus a margin.
That is, on take-off planes climb at different angles and rates. On landing they descend at the same angle. But still different rates. The higher your airspeed, the higher your descent rate due to the fixed glide path angle.
"There are no stupid questions, but there are a lot of inquisitive idiots." - from Citadel by John Ringo