Mike, It's all in the CFRs, the Code of Federal Regulations. More specifically, FAR Part 77 - Objects Affecting Navigable Airspace. The more general information you're looking for is in section 77.23, Standards For Determining Obstructions: *http://tinyurl.com/jt5wf *And airports are surrounded by imaginary "surfaces" dependent upon their runways and approaches; these deal with the airspace immediately surrounding airports, in section 77.25: *http://tinyurl.com/e56rg* Horonjeff/McKelvey's "Planning & Design of Airports", fourth edition, describes it in detail in Chapter 7 as well. Greg Rendell greg@xxxxxxxxxxxxxxx KPHL Michael Burris wrote: > AIRLINE: > > Does anyone know if the FAA has a standardization spec > for the blinking-red aircraft warning light that sits > atop highrises? > > Since they appear similar, I would think so. I wonder > what the height requirements are for a building to > have one placed there? > > Mike Burris > Cambridge, Massachusetts