Turbulence penetration speed?

[moespeeds]

Curious what guys are using for cruise in turbulence? I know what the book says, and I know it varies with weight, but what are you actually using?

 

[RV8JD]

Turbulence Penetration Speed

Van's does not publish Vb, Turbulence Penetration Airspeed (aka: Design Speed for Maximum Gust Intensity), and it is not required to be published for Part 23 aircraft (yes, I know E-AB's are not required to meet those standards). Vb is defined for Part 25 Transport Category aircraft.

But here is a good article discussing Vb for light aircraft:

https://www.aviationsafetymagazine.com/features/airspeed-turbulence-easy-adjustments/​

and another:

https://airfactsjournal.com/2020/12/understanding-vb-turbulence-penetration-speed/​

"A simple rule of thumb would be to split the difference and fly a speed that is approximately half way between Vs1 and Va. However, a slightly faster speed will help improve controllability in very rough conditions. Since airspeed will be varying considerably in turbulence, it is not important that the pilot try to maintain an exact speed, but rather work to maintain near a level attitude and not exceed either the Va or Vs1 limits."​

I saw another article that approximates Vb as 1.6Vs.

 

[Majorpayne317641]

I treat moderate turbulence as Va or less but mountain flying Vb or less because of the massive updrafts and downdrafts that occur in thousands of FPM. I also saw someone tried to extrapolate actual Va speeds for weight and a 6g limit for RV8 airframe unlike the normal category aircraft. From what I understand Vb is “rough air penetration speed” and is 1.6, CPA says it’s 1.7

 

[RV8JD]

Could have been me.

If you take the change in stall speed with changing weight into account, and the Aerobatic and Utility Category Limits into account, Flaps-Up Va looks like this:

Note: Van's states Va for the RV-8 (and RV-7) as 142 MPH IAS.

<Use this information at your risk!>