# Is there a limit of how close a runway can be to the water?

Somtimes planes can either come up short or overrun a runway, ending up in the water.

Is there some limit for how close a runway can be to the water? Does it factor into the runway safety area that is required to be clear of obstacles (i.e., is water an obstacle)? Is there any requirement for displaced thresholds near water?

-
If SFO is any indication, it can be awful close: richp.com/pics/aerial-05-20-01/sfo1.jpg –  Jay Carr Mar 27 at 19:30
Check out KCOI: img.airnav.com/ap/01869.jpg?v=JFCCQ4 -- a small GA airport for sure, but certainly close to water. –  mah Mar 27 at 20:00
Boston Logan and, to a lesser extent, JFK are also very close. Outside the US, London City and Hong Kong come to mind. –  David Richerby Mar 27 at 20:25
OK, so are there actually any airports that aren't right next to water? ;-) –  David Richerby Mar 27 at 22:27
In addition to JFK, consider LaGuardia -- which is also close to the water vertically; major storms have sometimes put the runway under water and shut down the airport. (I had a flight cancelled for that reason once.) And I seem to remember that JFK can handle seaplanes. –  keshlam Mar 28 at 2:50

FAA Advisory Circular (AC) 150/5300-13A covers "standards and recommendations for airport design." It does not include any restrictions on proximity to bodies of water, but it does make the following recommendation in paragraph 319(a):

It is recommended that the entire RSA and RPZ be accessible to rescue and fire-fighting vehicles such that no part of the RSA or RPZ is more than 330 feet (100 m) from either an all-weather road or a paved operational surface. Where an airport is adjacent to a body of water where access by rescue personnel from airport property is desirable, it is recommended that boat launch ramps with appropriate access roads be provided.

The actual FARs (14 CFR 139, Certification and Operations: Land Airports) also do not state a limit. The only reference to bodies of water of any kind is in §139.325 (Airport emergency plan) paragraph (e):

The plan required by this section shall contain provisions, to the extent practicable, for the rescue of aircraft accident victims from significant bodies of water or marsh lands adjacent to the airport which are crossed by the approach and departure flight paths of air carriers. A body of water or marsh land is significant if the area exceeds one-quarter square mile and cannot be traversed by conventional land rescue vehicles. To the extent practicable, the plan shall provide for rescue vehicles with a combined capacity for handling the maximum number of persons that can be carried on board the largest air carrier aircraft that the airport reasonably can be expected to serve.

So, bottom line: there is no limit, but airports are required to take water into due consideration when developing emergency plans, and the FAA looks at each airport and plan on a case-by-case basis during airport certification.

As for the rest of the world, I have no authoritative information; but as others have posted, it certainly seems like the situation is the same, there being numerous examples of airports worldwide built on natural or reclaimed land very close to water.

-

There is no such limit indeed. Princess Juliana International Airport in Sint Maarten is possibly the most iconic example of airport located near a water body, because of the beach over which airliners fly when approaching RWY 09. As other mentioned, they are numerous other examples of airports that may be even closer to a water body (i.e. without a beach in between).

-
What is so close to the water is not the runway, but a blastpad. The runway at Saint Marteen airport is almost 190m inland. –  molgar Sep 25 at 7:13

Water is not an obstacle. There are plenty of examples around the world where runways are built on purpose-reclaimed land and the ocean starts just a handful of meters from the end of the runway.

For some random examples, check Nice-Côte d'Azur or Gibraltar or St. Maarten.

-
...Or La Guardia –  voretaq7 Mar 27 at 19:41

Runway 28L and 28R at KSFO, as well as 19L and 19R, have their thresholds right next to the San Francisco Bay.

If you recall, in July 2013, Asiana Airlines Flight 214 landed short due to pilot error.

In November 1968, Japan Airlines Flight 2 completely missed the runway and landed in San Francisco Bay.

-

Not going by Barra Airport -

Barra Airport is famous for its beauty - boasting beaches, machair and hills - and all in a small island; Barra is a special place to visit - especially memorable if you fly in because of the beach landing strip. Washed by the tide twice a day, Traigh Mhor beach is reputed to be the only beach runway in the world to handle scheduled airline services.

-

The answer to the question is yes, there are limits. I'll expand for ICAO regulated airports, but this is also true for FAA ones.

ICAO defines an area surrounding a runway, called runway strip, which purpose is to:

a) to reduce the risk of damage to aircraft running off a runway; and
b) to protect aircraft flying over it during take-off or landing operations.


A water runway strip would not reduce the risk of damage to aircraft running off a runway. It would in fact increase it, so a runway strip cannot be made of water.

The size of the runway strip depends on the type of runway, but it ranges 150 m to 0m (zero) in width, and it must extend 30 to 60 m beyond each end of the runway (or the end of the stopways, if there are any).

So, the runway strip contains at least the runway (and its stopways) and extends beyond it on its ends, and sometimes (depending on the type of runway) it also extends to the sides of the runway, and it defines the limits to how close a runway can be to water.

Going even further, ICAO defines a Runway End Safety Area (RESA) for some types of runways which further increases the minimum distance of water to the runway.

Airports such as Sint Marteen, where the runway is almost 190m from the water, are just examples of how the runway strip and the RESA are applied as safety measures against aircraft running off a runway.

-

Here is Albert Whitted Airport, a GA facility in St. Petersburg, FL, which has actually juts out into Tampa Bay.