# Is there a minimum distance between a runway and a public road?

Does the FAA require a minimum distance the between the TDZ of a runway and a public road?

The reason I ask is because an aircraft landing at a small GA airport (Garnett Municipal, K68) came across the roadway I was driving on low enough that if I'd been 200 yards up the road he'd have hit my truck. Or at least he'd have had to go around.

From the satellite pic you can see that the end of the runway is about 30 feet from the road. The TDZ is about 150 feet. A 3° approach would put you just short of 8' AGL at the road, which is just about exactly how high he was. My truck has a clearance of 10', so it's quite possible to strike vehicles on the road if one is too focused on the runway.

Although it's not a highway (that's about 1000' from the runway), it's the only paved road going east/west for several miles so it gets a bit of traffic

Is it common to put a runway so close to a road?

• No, in fact there are public roads so close that they caution drivers to stop and listen, there is a pretty famous accident that a student pilot had during first solo. As a side note, he did quit flying at first but then went on to finish his ticket. You can read the NTSB report here Commented Jun 3, 2016 at 1:29
• Just missed my edit window, what I meant was that it isn't uncommon to have a road that close, although public use airports have to be built to some standards (the video I posted is a private airport). I'm trying to locate that standard for you and I'll post an answer when I find it. Commented Jun 3, 2016 at 1:37
• Internationally, there are some great counterexamples. Gibraltar, for instance, where the only road in runs across the runway (they do have officials that close the road for aircraft movements). Commented Jun 3, 2016 at 5:24
• @JanHudec I based the numbers in my question.on the white line. 3° at 150' is about 8'. I'd never seen anyone come in quite so low so I was wondering if the approach was abnormal but it appears that it was textbook. Commented Jun 3, 2016 at 12:02
• One thing worth noting is that even where there are laws, rules, or regulations, they often do not apply retrospectively. eg where an airfield was built before the law came into place, there is not always a requirement to update it Commented Jun 3, 2016 at 14:41

Yes, there is a minimum area that must be free of obstructions and closed to vehicles, but only for airports that have air carrier operations (see 14 CFR 139.309) or that receive FAA grants. AC 150/5300-13A - Airport Design has all the technical details; the actual distances are calculated from formulas, so there's no single answer. If you're really curious, you can read all the gory details in Chapter 3 and this FAA FAQ has a (very) simplified explanation:

What is the size of the RSA [Runway Safety Area]?

The RSA is a rectangular box surrounding the runway and is based on the runway design code. The dimensions range from 120 feet to 500 feet in width and 240 feet to 1000 feet in length beyond the departure end of the runway. (see FAA Advisory Circular 150/5300-13, Airport Design) Generally, on airports that serve air carrier aircraft, the RSA extends 250 feet either side of the runway centerline and 1000 feet beyond each end of the runway.

You didn't mention which airport you're asking about, but presumably it's either privately owned and/or doesn't receive FAA grant money.

• It's K68. Very small, one runway, non-towered airport owned by the city of Garnett, KS. I have no idea about funding. I've seen that beach in St Maarten on tv. That's pretty wild. I'd love to see that in person some day Commented Jun 3, 2016 at 2:36

No (for smaller airplanes and airfields)

The limit is not regarding the runway to the road but the minimum height an airplane (landing or starting) has to have over the road.

You can see this very well in the picture:

A departing aircraft (runway 19) can be quite close to the road and use the "full" length of the runway as it is built. As long as the thrust is not too big (for smaller airplanes), there is no reason for a restriction.

A landing aircraft (runway 19) requires a minimum height (15 feet i think) and is therefore not allowed to land at the beginning of the runway but not before the big, white bar. This is called a displaced threshold. So the runway, for landing aircrafts, actually does not begin so close to the road as it "looks" like.

This way, departing aircrafts will have a longer runway available, which is a critical point in aviation (safety).

It's btw the same for a departing aircraft with direction to the road (so using runway 19 + 18 = 37 => runway 01). It is not allowed to lift off after the displaced threshold.

The FAA regulates aviation and aircraft, not road layout or runway locations.

The standard glideslope is three degrees, pretty shallow, so aircraft often travel long distances low above the ground prior to landing. Trees are a big issue. On the island of St. Maarten 747's fly as low as 10-15 feet right over a heavily populated resort beach and pathway.

Credit: Blick, William E. Princess Juliana International Airport

Often there are signs warning of low-flying aircraft so that motorists are not startled.

Don't worry about it too much, planes are way more flimsy than a truck, so as long as the 50 gallons of aviation fuel does not catch on fire or explode, your vehicle will come off much better in the rare event of a collision.

• There's pretty good visibility there, so I'm sure they would see something coming... as long as they are paying attention. I can imagine a new pilot being focused on the landing, airspeed, configuration, etc and forgetting completely about road traffic. It just totally surprised me seeing how low he came over the road. I was watching a couple of crop dusters taking off and landing there yesterday and they were quite a bit higher than this plane was. But those crop dusting planes are really agile and powerful so they obviously don't need the whole runway. They have have an amazing climb rate. Commented Jun 3, 2016 at 2:22
• Do you have a citation for your claim that aircraft cross the beach at Sint Maarten at 10-15ft AGL? The photo looks much more like 30-40ft and crossing the beach at 10ft would surely result in clipping the airport fence. Commented Jun 3, 2016 at 5:23
• Also, please acknowledge the source of the image. Commented Jun 3, 2016 at 5:24
• @Richerby The fence is 8 feet high I think and the planes come right down over that fence. There is a roadway or pedestrian way right next to the fence. You can't see the fence in this photo. I was talking about the altitude near the fence. Commented Jun 3, 2016 at 8:21
• Totally OT, but I can see hanging out on that beach for a few landings as a novelty, but it certainly doesn't look like a relaxing vacation destination for spending the whole day... Commented Jun 3, 2016 at 12:49