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Runway 18 at Frankfurt Airport is one example of a runway which is numbered on only one side. Aircraft can only takeoff in the 18 direction, and cannot takeoff in the 36 direction, nor land in any direction except in an emergency situation.

What is the reason behind it?

Diagram of Frankfurt Airport
Thomas Römer/OpenStreetMap data [CC BY-SA 2.0], via Wikimedia Commons

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    $\begingroup$ There are quite a few airports like this. Another example is Heathrow where take-offs from 09L only take place in exceptional circumstances due to noise abatement. $\endgroup$ – Simon Sep 9 '15 at 17:53
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    $\begingroup$ Kind of like st.maarten airport. You can only land and takeoff in the same direction. $\endgroup$ – Ethan Sep 9 '15 at 19:03
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Let us consider the operations other than takeoff on runway 18.

  • Takeoff Runway 36

    There are buildings not far off the departure end and directly after the end of the runway is a movement area and ramp. To safely takeoff they would have to clear that area and probably replace all the concrete with crushable concrete (more on this later). The buildings probably post obstacle clearance issues for engine out climb performance. The east-west runway north of 36 would have conflicting traffic and would have to be carefully sequenced. Lastly, that purple area to the north of the runway is probably a noise sensitive area you aren't allowed to fly over at low altitude.

  • Landing Runway 18

    You approach over a noise sensitive area, cross over operations on the northern east-west runway, overfly a building at extremely low levels (wheels on the roof) and have to make sure there are not airplanes on the ramp between the building and runway. Landing short would be nothing short of disastrous and every landing would be a risky operation with the close proximity of airplanes and buildings. Glideslope services would probably not be available due to ground obstacles.

  • Landing Runway 36

    This is the least problematic approach. The problem is in missed approaches and long landings. There is no safety area at the end of 36 and a runway excursion past the end of the runway would be catastrophic. To mitigate this they could re-pour the ramp concrete with crushable safety concrete, but that would probably make using ramp and building unsuitable. If traffic goes around they conflict with aircraft on the northern east-west runway and have a noise sensitive area to deal with.

In comparison to the above, taking off to the south only requires a blast fence just north of the runway to protect the ramp and building from jet blast. There are no logistic issues in aircraft movement on the ramp and the building is not in danger of being hit.

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    $\begingroup$ In short, you can take off with your back to an obstacle but the other three things are right out :-) $\endgroup$ – Steve Jessop Sep 10 '15 at 7:39
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    $\begingroup$ One more reason is the chemical plant nearly directly below the extended runway centerline north of the airport (very slightly east of it) in Höchst. I can imagine very well that this had an effect on the decision if planes should fly there or not. $\endgroup$ – Florian Apr 22 at 14:59
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looking at the chart, you can see buildings right past the treshold on the opposite end. Taking off to the north (or landing from the north) would put you dangerously low over those buildings, not a safe situation at all.
Also, there are no doubt very strict noise restrictions in place which ban overflights of the towns and city districts just north of the airport, further restricting the usefulness of maintaining navigation aids and other things needed to make it an operational runway in both directions.

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If you see the runway orientation, it is clear that any landing in the runway 18 (Runway West) will interfere with air traffic in the other runways (Runways North, 07C/25C and South, 07R/25L).

The same thing goes for takeoffs to the north in that runway.

This is the reason the runway is used only for takeoffs in southbound direction.

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    $\begingroup$ In a general case, that sort of an issue can be solved; Boston Logan (KBOS) and Philadelphia (KPHL) are good examples. They routinely land on runways that either intersect or whose finals or missed approach paths would cross. To keep operations safe, they manage the spacing of inbound aircraft so that they're separated in time so that even if EVERY aircraft went around, they'd alternate crossing over the airport. I suspect that the noise sensitivity is what drives the non-use of 36 takeoffs and 18 landings. (Not landing on 36... maybe the extra capacity just isn't that needed??) $\endgroup$ – Ralph J Sep 9 '15 at 16:35
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    $\begingroup$ Amsterdam has crossing runways that are operated in both directions, no problem with that. Just don't use them at the same time :) If your assertion were true the runway would not exist at all because the missed approach path crosses another runway. $\endgroup$ – jwenting Sep 9 '15 at 20:30

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