Turbulence: Rotor wing vs fixed wing

[NealRomeoGolf]

I ask this purely out of ignorance. I've never been in a helicopter. If a rotor wing were to hit the same turbulent pocket of air as a fixed wing, do you feel the same level of turbulence or is it different? Does the fact that the wing is rotating change anything?

Now that I think of it, is wing loading a thing in a helicopter?

Please teach me.

 

[Bell206]

If a rotor wing were to hit the same turbulent pocket of air as a fixed wing, do you feel the same level of turbulence or is it different?

In general, rotorcraft handle turbulence better than airplanes. This is further defined by the main rotor type and several other items how much a better ride you experience. However, there are some helicopters that have turbulence limitation like an R22.

Does the fact that the wing is rotating change anything?

It has more to do with the lifting structure, i.e. the M/R system, is flexible and "adjusts" to the air movement vs an airplane wing which rigid and doesnt.

is wing loading a thing in a helicopter?

Helicopters are measured by disc loading (rotor disc area) which is the equvilent to wing loading in airplanes.

 

[Piperonca]

Anybody on PoA that flies V-22? Wonder how the Osprey handles turbulence. It has a high disc loading, but how about wing loading?

https://verticalmag.com/features/20112-flying-the-v-22-html/

 

[Llewtrah381]

I fly a gyro (Magni M-16) and the gyro does waaay better in turbulence. I used to fly over to my lessons in my Warrior, get tossed all over in the typical TX afternoon thermals, then get in the gyro and think “huh - the wind calmed down a LOT”. Nope. The ride home in the Warrior was at least as bumpy.

That said, because it’s open cockpit, when there are gusts, even a lightening in the seat gets my attention (literally to this day - I just landed in the gyro). I never go zero, let alone negative g, but it’s definitely different.

 

[Bell206]

It has a high disc loading, but how about wing loading?

I dont know much on the V22 but I dont recall seeing wing loading ratios on other tiltrotors like the XV15 and AW609. I've only seen disc loading and lift/drag ratio numbers on those. And given tilitrotors use rigid prop-rotors my guess is they would handle turbulence similar to a fixed fixed vs a helicopter MR system.

 

[Maxnr]

Most airplane pilots operate at Va or below in rough air or enroute descents. Helo pilots, not so much. Helos don't have a Va. They may have a Turbulence penetration speed suggested in the Rotorcraft Flight Manual, but its not a limitation. Mostly for passenger comfort.
Helicopter pilots mostly make descents at or near Vne, even in turbulence. Think about it. The rotor system is always operating at speed, even in a hover.
I used to fly the BH 214 "Super Transporter" that had a Fly-by-wire Synchronized elevator (1972 tech) that was famous for doing its own thing in turbulence. One would go up, the other down. Had to slow and re-initialize the system. That old cow had a higher Vne than the Sikorsky 76, but would wear you out in bumpy air.

 

[Bell206]

They may have a Turbulence penetration speed suggested in the Rotorcraft Flight Manual, but its not a limitation

FYI: in the case of the R22 it is an RFM limitation for pilots with certain levels of experience and training to continue flight into moderate, severe, or extreme tolerance. Its also the topic of an AD which changed the RFM.

 

[Maxnr]

FYI: in the case of the R22 it is an RFM limitation for pilots with certain levels of experience and training to continue flight into moderate, severe, or extreme tolerance. Its also the topic of an AD which changed the RFM.

I speak fluent Sikorsky but once parked next to a R22. I appreciate the info on the Robbys.

 

[Velocity173]

Moderate turbulence penetration speed in the UH-60 is Vne minus 15 kts or max range, which ever is less. Not a hard limitation but not something I’d wanna bump up against on a regular basis either.

 

[Maxnr]

Moderate turbulence penetration speed in the UH-60 is Vne minus 15 kts or max range, which ever is less. Not a hard limitation but not something I’d wanna bump up against on a regular basis either.

Way back in the last century, when I was a student helo pilot, the aerodynamics platform instructor said something that stuck with me.
" Rule of thumb: Max MPG for helicopters is at 90% of Vne." Realize that most helicopters are running out of fuel every time they take off. If you don't have a good reason to slow in turbulence, you won't have those days when the fuel gauge grows to the size of a wall clock.

 

[RussR]

I did my helicopter training here in OKC, which is kind of known for being windy and bumpy. I was a little worried that the R-22 was going to be just tossed around, a real rough ride. After all, max gross is only 1370, so it's basically like an LSA for weight.

I was pleasantly surprised. It was pretty smooth. The turbulence seemed to be felt more as a left/right turning movement (yawing) than an up/down jolt.