[Deritio]

Why would they?

They will probably want to fly across non easy terrain because otherwise you could just use some other means than an expensive helicopter.

Hight perhaps but you will fly across water, woods, power lines, cities.

[sokoloff]

Watch a helicopter take off sometime. It (almost) never lifts into a hover and climbs straight up. Instead, it lifts slightly off the ground and accelerates forward following the recommended takeoff profile.

That’s so the craft can stay in the “autorotation possible” section of the HV diagram as much as possible.