Why no lower than 57 kts in moderate + turbulence?

[JB77UK]

Hi all,

I understand in moderate+ turbulence we want to reduce airspeed to reduce structural loads, but why do you think in the R22 POH it states the number 57 kts as the absolute minimum?

R22 POH Limitations Section:
"Adjust forward airspeed to between 60 knots indicated airspeed (KIAS) and 0.7 Vne, but no lower than 57 KIAS, upon inadvertently encountering moderate, severe, or extreme turbulence."

I guess it is probably a performance issue - to be able to maintain best climb maybe, but that number is 53 kts...

Any ideas?

Without understanding more I think I would just aim for 60kts and try to keep the ship level.

Many thanks for your thoughts,

Jay

[JB77UK]

The definitive answer was provided Answer provided by Raven on another forum:

The airspeed you fly in turbulance is a range. 60 is the low point 71.4 (0.7 of 102) is the high point. If 0.7 of any other Vne (remember it goes down with altitude and tempurature) is less than 60, you must go 60. However, at 10,000 feet and 30 degrees, you cannot go 60, because your Vne is 57! Hence the one exception, "no lower than 57".