Helo Wake Turb

dan Rookie Lake Charles, LA (CWF)

Ok here's my question. When I was in the Army we would use wake turbulence rules for Large Helos (CH47) or for flights of 2 or more UH60's. I was always under the impression that Wake Turb was based on the aircraft's payload or take off weight rather than type of airframe. I have been told by others (not from the army) that this was incorrect to issue this to other smaller aircraft. Here's a scenario, A CH47 is departing RWY 15, and a C172 at a midfield taxi calls for departure, I issue hold for wake turbulence, departing large CH47. Is this wrong, and if so please explain why.
Thanks.

Roddy_Piper Resident Knucklehead Vegas baby

if the chinook, which is a large, departed from RY15 full length and the skyhawk, a small, wanted an intersection departure from RY15 then you must provide 3 minutes waiverable.

dan Rookie Lake Charles, LA (CWF)

That's what I thought.

Roddy_Piper Resident Knucklehead Vegas baby

even if it was a blackhawk departing, u need the 3 minutes waiverable since it's a S+

atcpookie Junior Member FAA Headquarters, Washington, DC

Agreed - - SRS rules - - small verses a large or small +

dan Rookie Lake Charles, LA (CWF)

Glad to see that the Army's ATC actually got something right for a change. lol We always had to use it, but it seems that some people automatically lump all helo's into the small (Bell Jet Ranger) grouping. Thanks for the confirmation guide.

MikeATC Retired FAA, NATCA Member Nashville TN

Feels good when you are right. You have to remember that helicopter wake turbelence/rotor wash is different and often more severe because it is in my opinon more of a downward force vs. the rotation that you get with fixed wing wake.

dan Rookie Lake Charles, LA (CWF)

Exactly, when talking about this with guys at work I tell them, I'd rather stand in the "wake" of a King Air 200 than in that of a Blackhawk.