Wake turbulance for...

DennyCrane Rookie

Ok. Here is a scenario. Lets say we have runway 18/36 the parallel taxiway (A) has taxiway A1 at the approach end of 18 and A8 at approach end of 36. This facility has no helipad so helicopters go to the intersection of A and A8 for takeoff. A regional jet has just taken off runway 18. Helicopter requests to takeoff with a heading of 155 (taking him directly through the flight path of the departing RJ.) Some have told me that it is an intersection departure and must wait 3 minutes. According to the .65 the direction the course the helicopter flies on takeoff is it's own runway so I filed it under intersecting runways and there would not be wake turbulence unless the RJ had been a heavy aircraft. Of course morally the helicopter should be advised of the wake turbulence but I was wondering what more experienced controllers would have done as I am a fresh out of the academy developmental. Thanks

MikeATC Retired FAA, NATCA Member Nashville TN

Legally it is an intersection departure, the FAA would gig you for not following wake turbulence procedures for intersection departures if something happened. The problem is if the helo pilot takes off into the wind (same direction as the runway heading) then turns on course it falls into the intersection departure rules.

If the helicopter is a local user, I'd suggest stopping by and talking to them and ask them to state that they waive the wake turbulence delay if they see a RJ or other large aircraft departing. I've done this at several of the airports that I've worked at, and the pilots were very receptive to the suggestion.

atcpookie Junior Member FAA Headquarters, Washington, DC

First of all..... if they are takeing off from A8 that's at the approach end of the runway, there is no legitimate way it can be called an intersection.

With that being said..... as far as the .65 goes it ALL rests on where you say "cleared for take off"

If you say "Taxiway A at A8 cleared for takeoff" then you treat it as a parallel runway with an approach end departure.

If you say "Taxiway A8 at A cleared for takeoff" then you treat it as a intersecting runway.

If you say "Runway 36 at A7 cleared for take off" then you treat it as a intersection departure.

If you say "Runway 36 at A8 cleared for takeoff" then you're just waisting words because it's an approach end departure. Say "Runway 36 cleared for takeoff"

So because the HELO is treated as a small the only time you have to hold for wake turbulence is for an intersection departure like "Runway 36 at A2-A7" or for an opposite dirrection departure like "Runway 36 cleared for takeoff" after a RJ departed runway 18.

Hope this helps.

GLF5 Senior Member

How about "Present position, cleared for takeoff."

garlandatc Junior Member

Wow. I think that your RJ from 18 vs your Helo from A8 would be an opposite direction and still need a hold. Regardless. If your parallel taxiway and rwy 18/36 are separated by 700 ft from centerlines or 600 feet from edges you do not have to concern yourself with a hold for wake turbulence regarding small following a large. Otherwise what MikeATC said.

MikeATC Retired FAA, NATCA Member Nashville TN

I read his question like Garland did, the RJ departed RWY 18, and the helicopter was departing from the intersection A8 at the departure end of RWY 18 (which makes it same runway).

atcpookie Junior Member FAA Headquarters, Washington, DC

Also, the .65 only has rules for through the flight path wake turbulance with reguards to a heavy/B757 and small vs large departing oppsite direction on the same runway.

garlandatc Junior Member

Say again.

atcpookie Junior Member FAA Headquarters, Washington, DC

In the 7110.65 ...... the only rules that talk about "through the flight path" are those that deal with wake turbulance from a heavy aircraft or a 757. The only other rule that even comes close to "through the flight path" is opposite direction departures with a small aircraft departing after a large.

garlandatc Junior Member

True, also for same rwy is 3-9-7. WAKE TURBULENCE SEPARATION
FOR INTERSECTION DEPARTURES