Wake turbulence seperation from helipad (less than 760m) to runway
 

Hi ATC's

Any of you guys working at airfields with medium size helicopters departing from a helipad, where the helipad is less than 760m to a runway where you depart light aircrafts?

If yes, do you provide a 2 min (or 3 min from intermediate) wake turbulence seperation to the light aircraft departing from the runway?

According to PANS OPS DOC 4444, 5.8.3.1, a 2 minute departure seperation need to be in place in case. So if you have a helipad closer than 760m, would you as ATC interpret the helipad as being the same definition as a runway, and make wake turbulence seperation to the light aircraft departing from the actual runway?

Thanks in advance for any inputs

No, at LHR we have a helipad/FATO that’s 250m from the edge of the nearest runway, and we only apply wake separation if an A380 is using the runway.

I do realise that’s not the question, that you were asking about lighter aircraft on the runway behind a heavier helicopter, but the theory holds.

See ICAO Annex 14 vol 2, table 3-1:
https://cimg5.ibsrv.net/gimg/pprune....93a80f8ac.jpeg

Hi Gonzo

Thanks for the info and reference to FATO seperation.

Seems FATO only deals with the seperation for the helicopter departing the helipad. Do you know if it also goes the other way around. So if you depart a medium helicopter from a helipad 300m from the runway, can you then depart a light aircraft from the runway without wake turbulence seperation?

Interesting question. I do not apply wake turbulence separation between medium/light when having paralell operations from FATO and RWY (distance between is approx 150m), and none of my collegues do either. This was up for discussion at my unit when FATO was established, and it was concluded that 4444 5.8.3.1 does not apply in this situation. Departure direction from our FATO is perpendicular to the RWY, and can in no way be interpreted as parallel as is a prerequisite for 5.8.3.1 to apply.

I will however caution of wake turbulence if there is crosswind together with traffic information if the winds are such that wake will blow towards the light.