http://edition.cnn.com/2016/01/05/aviat ... index.html
102-story Seattle skyscraper plan deemed a 'hazard' to aircraft
By Barry Neild, CNN
Seattle: The sky is not the limit for developers, says the FAA.
(CNN)—With skyscrapers reaching higher each year, it seems the sky's the limit -- unless that sky is full of airplanes.
That's the problem facing developers in Seattle who have had plans to build a mighty 102-story tower rejected by authorities.
Their proposal for a super tall office, apartment, hotel and retail skyscraper in the city's downtown represents a "presumed hazard" to air traffic, says the Federal Aviation Administration.
It seems the proposed tower, known as 4/C and slated for an empty lot on the corner of Fourth Avenue and Columbia Street, would be located too near Seattle's airports and the headquarters of aircraft manufacturer Boeing.
On January 4, the FAA issued a "notice of presumed hazard" to Miami-based Crescent Heights, the company behind the proposed 339-meter (1,112-foot) building.
The structure as described exceeds obstruction standards and/or would have an adverse physical or electromagnetic interference effect upon navigable airspace or air navigation facilities," the FAA says in the notice seen by CNN.
Shorter is better
Not only that, but any cranes brought in to construct such a building could be a risk for helicopters serving a nearby medical center, it says.
All is not lost though.
The FAA says that by shaving the building down to 152 meters (499 feet), "it would not exceed obstruction standards and a favorable determination could subsequently be issued."
That would bring it down from a height just 42 meters shy of the Empire State Building to one that's actually slightly shorter than the Columbia Center, currently Seattle's tallest building.
The FAA tells CNN discussions are still ongoing, so watch this airspace.