Vortex Ring State

[RIretFL]

http://198.65.138.161/military/systems/aircraft/v-22-vrs.htm
"Barbs" > wrote in message
...
> In laymen's terms, could someone explain what the "vortex ring state"
(VRS)
> is in terms of a rotary-winged aircraft? One explication I'm looking for
is
> in terms of the V-22 Osprey....is VRS, with respect to the V-22 Osprey,
> where the wake by one rotor is opposite of the other rotor, causing a
> catastrophe in some cases?
>
>
>
>

[Barbs]

In laymen's terms, could someone explain what the "vortex ring state" (VRS)
is in terms of a rotary-winged aircraft? One explication I'm looking for is
in terms of the V-22 Osprey....is VRS, with respect to the V-22 Osprey,
where the wake by one rotor is opposite of the other rotor, causing a
catastrophe in some cases?

[Red]

"Barbs" > wrote in message
...
> In laymen's terms, could someone explain what the "vortex ring state"
(VRS)
> is in terms of a rotary-winged aircraft? One explication I'm looking for
is
> in terms of the V-22 Osprey....is VRS, with respect to the V-22 Osprey,
> where the wake by one rotor is opposite of the other rotor, causing a
> catastrophe in some cases?
>
Strictly in "layman's terms" the simplest non-technical explanation is this.
When a rotor is climbing or holding a steady altitude, the air that the
rotors disturb to get lift is moved downward away from the rotors.

When descending the rotor is often within the air that has been disturbed by
the rotor. There is reduced lift provided by the rotor in this disturbed
air. As long as the rotor can provide more lift than required, no problem.
But if you descend too fast and have little or no forward motion to keep the
rotor in undistrubed air a serious situation develops, meaning if you are
too low to recover you fly into the earth.

Of course this only applies if you really believe the rumor that
helicopters, and bumble bees can fly.

Red

[Thomas Schoene]

"Barbs" > wrote in message

> In laymen's terms, could someone explain what the "vortex ring state"
> (VRS) is in terms of a rotary-winged aircraft? One explication I'm
> looking for is in terms of the V-22 Osprey....is VRS, with respect to
> the V-22 Osprey, where the wake by one rotor is opposite of the other
> rotor, causing a catastrophe in some cases?

In simple terms, Vortex Ring State occurs when a helicopter is descending so
fast that the movement of air up relative to the rotor is faster than the
rotor can pull air downward to produce lift. The result is turbulent
airflow through rotor disk and a loss of power.

http://www.copters.com/aero/settling.html

It occurs with conventional helicopters as well as Osprey. The major
difference is that most regular helos don't run into the asymmetric lift
problem that results from VRS in the V-22 if only one proprotor gets in that
state.

--�
Tom Schoene Replace "invalid" with "net" to e-mail
"If brave men and women never died, there would be nothing
special about bravery." -- Andy Rooney (attributed)