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FAA Design Specifications

FAA Design Specifications

FAA Design Specifications

(OP)
I am reviewing an antenna platform for the FAA, which does not appear to be designed by a structural engineer, but rather a mechanical engineer.

Everything about this platform seems to be overdesigned by a factor 3-5 based on the stated criteria on the drawings, from the LRFS and foundations.

Is anyone familiar with any structural design criteria the FAA might have that I am not aware of?

RE: FAA Design Specifications

which "FAA" do you mean ? is this an airport radar platform ?

another day in paradise, or is paradise one day closer ?

RE: FAA Design Specifications

(OP)
yes, my apologies, the federal aviation administration in the US

RE: FAA Design Specifications

Try searching for FAA Advisory Circulars. I don't know whether one covers this subject, but FAA requirements are often found in these documents.

RE: FAA Design Specifications

More than likely, for a radar mount, the design was controlled by lateral deflection criteria in a high wind situation, not stress.

Mike McCann, PE, SE (WA)


RE: FAA Design Specifications

Did a radar reflector at a major airport under FAA guidelines a few years back and that was certainly the case

Mike McCann, PE, SE (WA)


RE: FAA Design Specifications

would there be ACs for designing ground structure ? maybe ... but ACs are generally for airworthiness matters.

if it is a stiffness design, then it could look "heavy" ? what do the calc's show ? what sort of wind load ? is it realistic for the location ? is the deflection criteria overly tough ??

another day in paradise, or is paradise one day closer ?

RE: FAA Design Specifications

Deflection criteria will be very tight. The error resulting from deflection of aids to navigation and radar can be life-threatening. The radar is useful to about 60 miles, so a single degree of rotation of the structure supporting the installation can result in a mile of error at that distance. If the structure is on-airport, consider the criteria for jet blast if appropriate, although I think they restrict the location of radar to outside those areas. Start with FAA AC 150/5300.

RE: FAA Design Specifications

If I remember correctly, since the structure was a first if it's kind use-wise, and there were no written FAA deflection guidelines for the use, we settled on L/1000 or 1", whichever was less.

Mike McCann, PE, SE (WA)


RE: FAA Design Specifications

(OP)
guys, thanks for the input. the platform is pretty simple and just supports lightweight yagi antennas, like the one you used to use for tv. The platform is located outside of the runway safety area and not subjected to jet blast.

i dont want to give too much away but the platform was clearly not designed by a structural engineer, as evident by the details, the design criteria included and the drafting of the set in general. There are over 40 L5x5 braces on this 15'x110' x11'tall open platform!

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