In the situation you mentioned you will have 5mph airspeed and 0 groundspeed so you're correct.
Hope this helps guys!
The following combination of conditions is likely to cause
settling in a vortex ring state in any helicopter:
1. A vertical or nearly vertical descent of at least 300
fpm. (Actual critical rate depends on the gross weight,
rpm, density altitude, and other pertinent factors.)
2. The rotor system must be using some of the available
engine power (20–100 percent).
3. The horizontal velocity must be slower than effective
translational lift.
Some of the situations that are conducive to a settling with
power condition are: any hover above ground effect altitude,
specifically attempting to hover OGE at altitudes above the
hovering ceiling of the helicopter, attempting to hover OGE
without maintaining precise altitude control, pinnacle or
rooftop helipads when the wind is not aligned with the landing
direction, and downwind and steep power approaches in
which airspeed is permitted to drop below 10 knots depending
on the type of helicopter.
Reference:
http://www.faa.gov/regulations_policies ... h_ch11.pdf
JRapt Posts: 8