Mast bumping

http://en.wikipedia.org/wiki/Vortex_ring_state

Wiki actually has a very good explanation.

From what I understand from the rotorcraft flying handbook, you encounter settling with power after entering VRS.

Settling with power does not imply that the helicopter does not have enough power (torque) to slow a decent. It is the addition of power (torque ie: adding collective pitch) that aggravates the condition. As more pitch is pulled the vortex generated increases and in turn increases the rate of descent. It only occurs at little to no forward airspeed, as the helicopter descends into its own downwash. The only way to recover is to move the ship out of the downwash.

It is not like a power on descent in fixed wing aircraft.

I only have a few hours of fixed wing and rotor flight training, so I am by no means an expert. Hopefully some of the more experienced pilots can help clear it up.

"Vortex ring state describes an aerodynamic condition in

which a helicopter may be in a vertical descent with 20

percent up to maximum power applied, and little or no climb

performance. The term “settling with power” comes from

the fact that the helicopter keeps settling even though full

engine power is applied." - Direct excerpt from the FAA Helicopter Flying Handbook

My observation is that the difference between the two is that you could, in theory, get out of settling with power if you just had more power. In vortex ring state, more power just makes it worse.

Nailed it.

I've been a commercial helicopter pilot since 2002. I have flown piston, turbine and twin turbine helicopters all over the world. I can absolutely promise you guys that VRS and SwP are two different things.

I know the FAA doesn't academically recognize the difference (although any non-US publication does), but if you ask any helicopter pilot in the real world to explain the difference to you, they will.

I fully understand VRS, but I guess I'm not getting SWP. How does it occur?

I want to fully grasp the aerodynamics. As an aspiring pilot and student, I want all the information I can devour.

About "Mast bumping" Will be my theme song while learning to fly:music_whistling:

I fully understand VRS, but I guess I'm not getting SWP. How does it occur?

I want to fully grasp the aerodynamics. As an aspiring pilot and student, I want all the information I can devour.

I think it's hard to grasp when you would actually experience it because you figure if a helicopter were unable to maintain altitude with full power, it wouldn't have gotten off the ground in the first place, but when you think about specific conditions it makes more sense. If you flew a fully loaded Huey from the beach in Iraq up to the mountains in Afghanistan, you might experience SWP because of the difference in air density. Namely, you were able to lift X amount of weight at sea level safely, but at altitude you exceed the ability of your engine to churn out enough downforce to keep in the air.

Like VRS you address it the same way, by increasing your forward momentum, and that will give you lift much in the same way that a regular airplane wing will, and that lift will supplement what you can get with power alone. It seems to me like VRS is something you have to keep an eye on at all times, while SWP will only really occur when you're pushing the limits either weight-wise or altitude-wise.