2,000 ft. FAA height limit in the U.S.

[Berwyn]

It's not a height limit per se, and the intention of the regulation is probably geared towards guyed masts and not skyscrapers. Any structure above 2000 feet must receive FAA permission to ensure it won't interfere with aircraft safety. They've granted permissions for guyed masts to exceed 2000 feet, but I don't know if a skyscraper developer has ever applied to the FAA to build higher so few know how the FAA would rule.

In 99.9% of the occasions, local municipal zoning would limit heights before the FAA gets involved. If a skyscraper developer in New York or Chicago applied to build a 2,250 foot building, and they received all local approvals, I can't see them saying no since their rejection will have to be based on some fact finding evidence. Nevertheless, it would make an excellent eminent domain lawsuit.

[Berwyn]

Originally Posted by JMancuso

i thought the 2000' mark was where the local jurisdiction ended and the FAA's began. for ex. a proposed 2,000' building in chicago would have to seek FAA clearance in addition to the city where anything shorter would have to simply be cleared by chicago only.

That's not true. The city still maintains jurisdiction regardless of the height. The FAA just has the final say, but the airport authority may have to compensate landowners. Around runways there are all sorts of land uses which are allowed by the city, but are denied by the FAA for obvious reasons. Purchasing avigation easements on behalf of airport authorities is big business.

[Berwyn]

Originally Posted by scalziand

^^^Not to mention that Chicago had also (fairly) recently given permission for a 2300' building; the CWTC. IIRC, the FAA did give permission for this.

I wish I saw your post before posting mine. That's an excellent find. So the FAA has granted permission for a skyscraper in excess of 2000 ft. I wonder if this was the first and only official request to the FAA for something other than a guyed mast.

[seaskyfan]

Seattle has a height overlay district around Boeing Field (officially King County International Airport). It's adopted as part of the land use code - you can get exceptions for height but one of the criteria is that it has to be cool with the FAA. Not sure what other jurisdictions do - Seattle can be kind of anal so they may have just put in the height overlay to avoid any challenges with FAA rules.

Link to the relevant section below:

http://clerk.ci.seattle.wa.us/~scrip...p1.htm&r=1&f=G

[Nomadd22]

Originally Posted by JMancuso

i thought the 2000' mark was where the local jurisdiction ended and the FAA's began. for ex. a proposed 2,000' building in chicago would have to seek FAA clearance in addition to the city where anything shorter would have to simply be cleared by chicago only.

The FAA has say in pretty much anything over 200'. Over 2000' is presumed to be not allowable unless the builder can make an compelling case that it won't infringe on utilization of airspace or cause a hazard. Even the KVLY mast in North Dakota wasn't exempt. It reached 2063 feet because the rule only applies to the structure, and you're allowed to add an antenna above the 2000' point.

That wasn't my summary I posted before. It was the official FAA notice with the reference "14 CFR § 77.17(c)". I'm not sure how to make it clearer.

[Pizzuti]

here's your compelling case that it won't interfere with airspace:

The FAA already banned direct flights over Manhattan after 2001. There's no reason for a plane to be there so there's no reason a building of any height will interfere with airspace. So even if they built a 3,000 foot tower it would not interfere with any flights. The only planes that have hit buildings in NYC since 2001 (and there has been one incident that I know of) was a small plane that got lost and wasn't supposed to be in Manhattan in the first place, and crashed into a relatively short apartment building.

I don't know about Chicago, Los Angeles, Seattle, or Houston, but I'd assume that the interest in having flights going directly over Downtown is not all that compelling either, and they might someday see the same kind of Downtown bans on passing flights that we have at D.C. and NYC, if they don't already. Flights have millions of square miles of open airspace to navigate across the entire country; blocking out the few dozen square miles of airspace that contain tall buildings would be nothing.

It's one thing to have a huge TV antenna in the middle of a huge field, where the only thing to indicate that you're flying near a structure is the light on the tower itself. It would be easy to miss. But I'd say you ALWAYS know you're flying over a city. I'm sure the plane's computers tell you you're near or over Manhattan long before you get close or low enough to have to dodge individual buildings.

[Nowhereman1280]

^^^ Ironically air traffic over downtown Chicago has increased dramatically since 9-11. Mayor Daley forcibly (as in went out with bulldozers in the middle of the night and demolished x's into the runway) Meigs Field which was a small public airport on an island along downtown Chicago's lakefront. Once he did that, airspace over downtown was no longer restricted in any way. It used to be heavily restricted (as is the space around all airports) because of Meigs. There is constant traffic over downtown Chicago now at probably about 4000-5000' and up. In fact, its more likely that you see an airplane somewhere above you whenever you look up than not if you are downtown.

For some reason (maybe we feel removed from 9-11 or maybe its our inferiority complex kicking in again and no one here thinks anyone would bother attacking lowly Chicago (why would a terrorist launch an attack on the El, its already falling apart on its own..)) Chicagoans don't seem to be very concerned about terrorism. Its only people from out of the city who go "oh, you live in a tall building? Aren't you afraid of terrorists living there?"

[Mr Downtown]

Originally posted in 2007:

The ancient common-law rule was that a property owner owned from the center of the earth to the heavens: Cujus est solum ejus est usque ad coelum. However, at the end of World War II, the Supreme Court decided U.S. v. Causby, 328 U.S. 256 (1946), giving the federal government control over airspace needed for avigation. That came to mean all airspace above 2000 feet, and even lower altitudes near airports.

In 1965, seeing an increasing number of applications for radio masts more than 2000 feet high, the FAA promulgated this federal regulation:

14 CFR 77.13

(c) A proposed structure or an alteration to an existing structure that exceeds 2,000 feet in height above the ground will be presumed to be a hazard to air navigation and to result in an inefficient utilization of airspace and the applicant has the burden of overcoming that presumption. Each notice submitted under the pertinent provisions of this part 77 proposing a structure in excess of 2,000 feet above ground, or an alteration that will make an existing structure exceed that height, must contain a detailed showing, directed to meeting this burden. Only in exceptional cases, where the FAA concludes that a clear and compelling showing has been made that it would not result in an inefficient utilization of the airspace and would not result in a hazard to air navigation, will a determination of no hazard be issued.

As far as I can determine only one mast higher than 2000 feet has been approved since this rule was adopted, presumably on a showing of engineering necessity due to the foothills of the Sierra Nevada. It is hard to imagine any "clear and compelling" argument of necessity that a developer could make to overcome the presumption that anything more than 2000 feet high is prima facie a hazard to avigation.

[Nowhereman1280]

^^^ I dunno, maybe the argument that "The building next door is 2000' already and if you let me build my building it will generate maximum tax return for the government.

[Mr Downtown]

Different government. What does the FAA care about Cook County tax revenue?

You guys can dream all you want, but it's a rule the FAA put in place so it wouldn't have to decide the issue case by case. Those are the hardest kinds of rules to change.

[Nowhereman1280]

^^^ Huh? The rule implies that it would be determined on a case by case basis. Previous to the rule it wasn't determined on a case by case basis because there was no rule officially limiting the height of towers. All this has done is change the status quo from "build whatever you want, but you have to get approval from us first", which was case by case, to "You can't build whatever you want, but if you want to build something we don't allow, ask for approval from us" which is also case by case. I know you do your research, but from what I know of you, I don't buy that you are an expert on FAA and FCC regulation who can simply dismiss everyone else in this thread...

[JManc]

i love flying into chicago...the view is to die for.

[Tower6]

It is hard to imagine any "clear and compelling" argument of necessity that a developer could make to overcome the presumption that anything more than 2000 feet high is prima facie a hazard to avigation.

I would think a solar tower might meet those requirements. Enough green energy to power a small city. In order to be efficient, they need to be very large.

[JDRCRASH]

It's probably only a matter of time before the limit is lifted...

[BrandonJXN]

^ And how do you figure that?

[Pizzuti]

^Because it was set at 2,000 feet when 2,000 was beyond the reasonable height for any structure.

As structures increase in size and push against that limit, it would be reasonable to bump it to 3,000 feet. If structures continue to approach they might raise it again.

I'm sure that people in the 1950s thought a half-mile tall tower was Science Fiction material, barring the pipe dreams of ambitious architects.

[Mr Downtown]

What in the administrative record for this rule would suggest that interpretation?

[Alpha]

I believe the limit will exist further. Therefore there are good reasons

1.) The limit was not only set because of endangering air traffic. It was also set in order to limit range of broadcasting transmitters. And each structure if highrise, tower, chimney or guyed mast can carry broadcasting antennas, if desired.

2.) Is there a real requirement for highrise buildings taller than 609.6 metres? In fact the most economic height of multistory buildings is much lower ( in most cases below 150 metres, but even in special cases it is not higher than 300 metres ). Building completely habitable structures taller is just prestige and very expensive.

3.) The rule allows exceptions, when a good reason is given. For a solar chimney this will be surely the case, as it allows production of green energy and cannot be built less tall.

4.) In European Union, the tallest existing structure is 385 metres tall and nothing taller is at present under construction in European Union.

[Nowhereman1280]

^^^ Good thing the height limit doesn't actually exist as various evidence in this thread suggests. The FAA can block things, but the rules don't prohibit structures over 2000', they only demand that the applicant present evidence as to why they need to build over 2000'...

[Mr Downtown]

^Reread the rule. What possible evidence do you think a developer could present that would overcome that presumption?