Screenwall design near a helipad 2

[cmbyrd77]

I am designing a screenwall on top of a builidng that has a helipad right next to it. Does anyone have any documentation or resources they could share on what the basic wind speed would be for this. Typically for the location of this building it would be 90 mph, but I'm guessing not so near a helipad. Any help would be greatly appreciated.

Thank you!

 

[Ron]

You need to determine the wind and direction of such for helicopters taking off or landing. This will likely control over the 90mph basic wind speed as the frequency will likely be much greater.

As for the ADM, be careful with application of the provisions....they can be a bit confusing.

 

[fcu45]

If the screen wall is made of porous fabric, you may consider it as solid wall. That what I read in a manual before sometime.

You may need to put the load combination of (Max wind that Helicopter can fly in + the generated wind from the fans)
If the sum is less than the local design wind load. I assume you may design it to handle the 90 mph.

Good luck

 

[cmbyrd77]

Maybe I should have phrased my question differently. Does anyone know what the max wind speed of a helicopter taking off and landing is?

 

[WillisV]

http://www.aviationtoday.com/rw/wha...tor-Downwash-Velocity_75113.html#.UGsNuVEmZ8E

 

[WillisV]

and Table 1 of:

http://81.70.242.211/eab1/manual/Ma...er Rotor Wash in Hover and Forward Flight.pdf

Looks like 30-45mph max. Design for 90 and move on.

 

[TLHS]

Ron, the frequency would be significantly higher, but the deviation would be much less. So rather than the situation where designing for a 30 year return period wind would be more significant than a 10 year wind, the fact that there is frequent wind shouldn't have much effect, as the upper limit of the force is likely fairly set regardless of the number of repetitions. You won't get a crazy hurricane helicopter one day

 

[flight7]

If your screenwall is close enough to the aircraft to be affected by the downdraft, it's probably too close to be permitted for safety. Check

http://www.faa.gov/regulations_poli...fm/go/document.information/documentID/1020087

for helipad design requirements.