Airports for Drone Pilots
Understanding the interaction between airports and drone flights is obviously pretty important. This article covers what you need to know.
Airports typically have two types of traffic flying into or out of an airport: visual and instrument traffic. While instrument traffic relies on the instruments in the airplane and is usually referred to as flying IFR (for instrument flight rules), visual traffic flies based upon visual cues outside the airplane and is usually referred to as flying VFR (visual flight rules). While you will most often not be flying anywhere near an airport, it is important to have an understanding of the rules that manned pilot’s follow when flying in the national airspace (if for no other reason than to give you an appreciation for the fact that you are actually flying in the national airspace).
Another distinction to understand is that aviation in the United States is broken up into two categories: commercial and general aviation. If you’re flying on Southwest, you’re flying commercial. If you hop on a small Cessna, or even a privately owned jet, this is considered general aviation. Believe it or not, there is a lot of general aviation traffic out there. And while most smaller airports don’t have regular commercial traffic, they will almost always have general aviation traffic.
Runway Orientation
Before we get into the details of a traffic pattern, it is important to understand a little bit about how runways are oriented and when each runway will be used. Runways and their numbering are based upon the degrees of a compass. So, if you look at the compasses below, you can see that North is 360˚, South is 180˚, West is 270˚ and East is 90˚. Most people instinctively know that North is typically pointing “up” in orientation because that is how maps are usually shown. But if you have a hard time remembering West and East, just remember that it spells “WE” when North is pointed “up.” Take a look at the pictures below for reference.
So when you have an airport with runways going both North/South and West/East, you would have four runway numbers that looks like the figures below. What should be obvious in the picture below is that the runway numbers are just the orientation of the runways based on the degrees of a compass with the zeros cut off. North or 360˚ is 36, South or 180˚ is 18, West or 270˚ is 27, East or 90˚ is 9. Notice though, that the numbering on the ends of the runways is reverse of the way they are shown on the compass above. This is because the runway numbers use the compass direction that a plane is flying. The compass direction a plane is flying is called a heading.
Let’s use another picture to better illustrate that. The plane in the picture below is flying a heading of West or 270˚, this is why the runway numbers will be “reverse” of those on the compass. We are using the plane’s direction of flight on a compass to determine the runway numbers.
But how do we know when an airport would have planes landing on runway 36 instead of runway 18 or runway 27 instead of runway 9?
It’s all based upon the wind. When it comes to the way aerodynamics work, planes (and birds for that matter) prefer to fly into the wind. So the active runway is usually the one that forces air traffic to fly directly into the wind. I say “usually” because, as a pilot, I’ve flown into more than one airport where the “active” runway was not the one oriented into the wind. Pilots will sometimes continue using the runway that is “active,” even after the wind changes. If there is no real wind, pilots will ask for the active runway or listen on the radio to see what other pilots in the area are using. The picture below is a simple depiction of the active runway being 18 based upon wind blowing straight North or 360˚.
I said it above, but it is worth repeating: the active runway should be the one that would force the traffic to fly into the wind. This obviously doesn’t always end up being directly lined up with the orientation of a runway.
What if the wind was blowing Northwest, like the picture below? Here, planes would technically have the option of landing on either runway 36 or 27, since either would be landing as much “into the wind” as the other. In reality, pilots will listen to the reported weather and other traffic (on the radio) at that airport and fall in line with the runway that is already being used. As the picture below shows, if pilots are trying to land on both runways 9 and 18, it could be disastrous!
If the wind happened to be even just a bit more to the North (closer to 360˚) than pictured above, the active runway would likely be runway 18. If the wind happened to be a bit more to the West (closer to 270˚), runway 9 would likely be active. You’re always looking for the runway closest to being directly into the wind.
As an aside, one thing that can come in handy in real drone flying, but not necessarily on the Part 107 test is that planes flying in the pattern getting ready to land will be usually flying at 1,600 feet AGL (above ground level) and descending from there. So if you ever have permission to fly close to an airport or are simply really close to an airport with Class E airspace beginning at 700 feet AGL, you should be aware that you may see traffic at what seems like a low level.
Runway Patterns
Now that we have a grasp on runway orientation, let’s take a look at the pattern an airplane will fly when landing at an airport. Smaller airports that have a lot of general aviation traffic will allow traffic to fly what is called a pattern around the runway when landing. Granted, these smaller airports will also have instrument approaches for the traffic that is able to fly in IFR conditions, but these approaches are beyond our purposes under Part 107 and will not be discussed here. Remember, IFR indicates the use of instruments when pilots cannot necessarily see the ground or are flying in the clouds.
The use of a traffic pattern, however, is very common at smaller airports during VFR (visual flight rules) conditions. Take the picture below for example. Based on what we now know, this runway runs West/East, which means that the ends of the runway are numbered 9/27, respectively. The plane taking off in the picture follows the arrows, taking lefthand turns to stay in the pattern. This is standard for an airport. Some airports have a pattern based on right-handed turns but this would be noted on the sectional and is not typical.
First, the airplane would take the first lefthand turn and fly the crosswind leg of the pattern. Next, it would turn left again and fly the downwind leg of the pattern. It would turn again and fly the base leg of the pattern. Finally, it would turn again and fly its final approach until it landed. At every point along the way, a pilot should be making radio calls to ensure that other traffic in the area is aware of his/her position.
If the plane was flying in from another airport, it would enter the pattern at a 45 degree angle to the downwind leg and enter the pattern from there, as pictured below.
The interplay between airports and drone flights really becomes an issue at larger airports (think Classes B and C), which will usually accommodate both commercial and general aviation traffic. But a small plane flying into a larger airport, even if they are flying VFR, will be forced to follow the same general approach that all other traffic is flying. It makes sense if you think about it. You couldn’t exactly have a small Cessna just flying a pattern around the runway on its way in to an airport as big as La Guardia. Otherwise, the larger jets carrying people all over the country would be forced to just wait until the Cessna finished its pattern and landed.
Types of Airports
Towered
A towered airport has an operating control tower. At these airports, air traffic control is responsible for providing the safe, orderly, and expeditious flow of air traffic at airports that are busy enough to require this service.
Non-Towered
These airports do not have an operating control tower. Two-way radio communication is not required but it is always good operating practice for pilots to monitor other aircraft on the airport’s specified frequency. We will discuss how to identify this frequency in detail in the radio communications section.
That’s really it for airports and drone flights. Considering you most likely will not be flying close enough to an airport for this type of information to matter, the good news is, if you’re close to an airports and drone flights become an issue, you’ll be prepared. Don’t be like this guy and disrupt an entire airport!
Sources of Airport Information
For a drone pilot, there are a lot of sources of airport information. When flying near an airport, it can be helpful to know where to find this information. Each of the sources below can be helpful in certain situations.
Sectional Charts
A sectional chart is a type of aeronautical chart most commonly used by pilots flying under visual flight rules and is one of the best sources of airport information. These charts provide visual cues to a pilot (including things like lakes, towers, highways, etc.) but also provide a huge amount of information about the height of obstacles, navigational aids, radio frequencies, etc. The best place to become familiar with a sectional chart is on vfrmap.com. Below is a picture of part of the sectional for Cincinnati.
This article does not go in-depth on reading a sectional chart and its various symbols, but we have a separate guide on how to read a sectional chart here.
Chart Supplements U.S.
These supplements are available online from the FAA and contains information on public airports, heliports, and seaplane bases. These chart supplements provide a deeper look at individual airports and provide a ton of information about them. It provides a detailed picture, list of aeronautical charts with the airport, runways, types of lights used for each runway, navigational aids, radio frequencies, etc. While you should not expect detailed questions on how to read a Chart Supplement (which includes a lot of jargon and abbreviations), know that it has very specific airport information on it.
Aside from just being useful to know that this information exists in the Chart Supplements, it can actually help you in the event that an airport close to where you usually operate has a part-time tower or the airport is only operational between certain hours. If this is the case, sometimes the airspace will change to Class G during the non-operational times and this means you would not be required to get an FAA waiver to fly here commercially during those times.
Notice to Airmen (NOTAMs)
A Notice to Airmen or NOTAM is time critical information that is usually temporary in nature or might not be known enough in advance that it would get published on a chart. There is a national system that distributes NOTAMs. For our purposes, the easiest way to access a NOTAM would be through a system like Airmap.
The most recognized type of NOTAM is a temporary flight restriction or TFR. These are most commonly used for stadium or arena events as well as when the President (or someone else important) is flying into or out of an airport.
Automated Terminal Information Service (ATIS)
ATIS is a recording of the local weather conditions as well as runways in use, specific ATC procedures, or any airport construction activity. This is broadcast on a local radio frequency, usually in a looped format. Typically, it will be updated every hour, but it can be more often than that if necessary.
Radio Communication for Drone Pilots
Believe it or not, radio communication still plays a really vital role in safe air travel. But radio communication for drone pilots may seems like too much. This article explains why it isn’t.
In most situations, it is one of the only way pilots send and receive communications before, during and after a flight. Although, you may be reading this thinking “it is great that pilots need to use radio communication, but what on earth does this have to do with me piloting a drone”? As I’ve said before, a lot of it boils down to having an appreciation for flying in the national airspace. But with radio communication, there are actually times when it would be really helpful to a drone pilot to have a basic understanding of the language used on aviation radio calls. In particular, it would be really helpful if/when you are flying close to an airport, large or small, as it will make you much more aware of the amount and location of traffic in the area.
Radio Frequencies
There are a number of common radio frequencies used for various purposes. These are provided below with a short explanation of the use for each. No need to memorize every detail, but you should know what frequency you need to tune into in order get certain pieces of information and where they are used in various types of radio communication.
Common Traffic Advisory Frequency (CTAF)
CTAF stands for Common Traffic Advisory Frequency. It is a term that is used broadly for a frequency used to coordinate arrivals, departures, positions of aircraft, etc. at an airport. This frequency can come in many different forms depending on the airport. Two of the most common varieties of a CTAF are UNICOM (for Universal Integrated Community) and MULTICOM (which is not an abbreviation or acronym for anything).
A UNICOM frequency is usually used at airports that have a low amount of general aviation traffic and also do not have an active control tower. At some airports, the UNICOM may have a staff member receiving radio communication (in addition to any other pilots) and can provide information like weather, wind, active runways, etc. Sometimes the UNICOM will be operated by a company located at the airport that can provide fuel service or get a taxi for a landing pilot. A UNICOM station will be listed on a sectional chart if the airport has one. Check out the guide on reading a sectional to see where that info shows up on a sectional chart.
A MULTICOM frequency in the United States will always be 122.9 MHz. This frequency does not have a ground station or anyone at the airport providing information or services. Instead, this frequency is used just for the purpose of allowing air traffic to provide location information to one another.
Some airports have what is called a flight service station or FSS. An FSS is an air traffic facility that provides information and services to pilots but is not air traffic control. Instead, these facilities provide a number of flight related services to pilots. This could include NOTAMs, filing flight plans, submitting pilot reports or getting weather reports. Additionally, if you call 1-800-WX-BRIEF to get a weather briefing, you will be transferred to the weather service for the local FSS. While this all may seem very similar to a UNICOM, just know that an FSS is fully staffed and provides much more comprehensive services than a UNICOM.
AWOS and ASOS
AWOS or an Automated Weather Observing Systems is an automated, configurable weather system at an airport that provides looped, real-time information and reports on weather conditions at an airport.
ASOS or an Automated Surface Observing System is another type of automated weather station, but is more sophisticated than an AWOS and can actually gather enough information to generate weather forecasts. It can tell a pilot the type and intensity of precipitation, visibility issues caused by fog or haze, and track shifts in the wind.
Radio Communication Procedures
Aviation Alphabet
It may seem that the aviation alphabet is just a way to make people that don’t know it feel like they’re on the outside of an inside joke. But, in reality, we’ve all been on the phone, trying to give out our e-mail address when the person on the other end of the phone swears that it started with a “B” instead of a “D”. You correct them by saying, “no, D as in dog.” And now you understand the need for a phonetic alphabet when the primary communication device you have is a radio. The aviation alphabet is really just a uniform way to make sure that the people on both ends of the radio communication really understand what was said. The implications of a mis-communication when it comes to air traffic is a lot worse than not getting an e-mail. The below infographic includes all of the proper words and their pronunciations for each letter of the alphabet. I didn’t include numbers because with the exception of nine (which is said as “niner”), the numbers are all just said like you normally would say them.
Recommended Traffic Advisory Practices
Using the alphabet shown above, pilots will make and receive radio calls for all kinds of information. When dealing with controlled airports, the radio frequencies are broken up to deal with the amount of traffic. Busy airports will usually have ground control stations, a tower control station, a flight service station, approach and departure stations, etc. Each of these stations is responsible for a different part of a pilot’s journey on the ground at an airport and into the air. If flying IFR (instrument flight rules), a flight plan is required and you will be based from radio frequency to radio frequency so that you are in constant contact with someone on the ground. This provides safety and allows for abundant air traffic.
For our purposes, we are going to stick with radio communication procedures that are pretty basic just so that you have an understanding of the information that is passed back and forth on a standard radio call. We’ve talked previously about traffic patterns. At a smaller airport with a UNICOM or MULTICOM, a pilot should provide position calls on its way into or out of an airpor to let pilots know where he/she is currently moving and which direction he/she is headed. When I learned to fly, we used the airport in Murfreesboro, TN. An example of the type of position call I would have made when flying into this airport would sound like this:
Murfreesboro traffic, Diamond One Eight Zero Mike Tango, left downwind for runway 36 to land, Murfreesboro.
This call starts out with the airport’s name “Murfreesboro.” The word “traffic” indicates that I’m speaking to other traffic in the area. “Diamond One Eight Zero Mike Tango” indicates that I’m flying a Diamond aircraft with a tail number ending in 180MT. “Left downwind for runway 36 to land” indicates my location in relationship to the airport. I’m currently in the pattern, on the downwind leg for runway 36. “To land” indicates that I’ll be landing on that runway. Finally, the call is ended with the name of the airport again for the sake of clarity.
Any time a pilot makes a position report like this, it should follow this same basic sequence. 1) Where you are; 2) who you are; 3) what you are doing; 4) where you are again.
Like I said at the beginning of this article, radio communication for drone pilots may seem like overkill, but even just listening to these radio calls without making any yourself could provide a lot of insight into any manned traffic in your area.
Latitude & Longitude
Let’s put all of this into practice because it makes a lot more sense when you see it in action. The picture below shows a piece of a sectional map with marks indicating 84˚N longitude and 39˚ W latitude. I’ve circled these marks in red so that they are easily visible.
In between each degree line for latitude and longitude, the hash marks are measured in “minutes.” Just like the minutes of an hour, there are 60 minutes between each “degree” line. Taking the same picture I used above, I’ve made the lines of longitude (and the 30 minute lines) red. Remember, the farther West you go, the larger the longitudinal numbers will get. So, New York will have a lower longitudinal number than Los Angeles because it is closer to the Prime Meridian.
Again, using the same picture that I used above, the picture below shows each of the line of latitude (and the 30 minute line). Remember, the farther South you go, the lower the numbers will get because they will be getting closer to the Equator, which is zero degrees latitude. So Miami will have a lower latitudinal number than Bangor, Maine because it is closer to the Equator.
If you’re still having a hard time fully understanding this concept, the video below is a test question that I walked through that explains this article in the context of an actual test question. Don’t skip this stuff because I can assure you that I’ve seen these questions when on the Part 107 exam and the renewal exam.
Antenna Towers and Drones
Antenna towers pose a specific threat to most drone operations. Most air traffic in the United States (and elsewhere), does not deal with this issue; however, with drone flight, it is very possible that you will be flying close to an antenna tower on purpose. For this reason, it is really important to know where to find information about antenna towers (location, height, whether it has guy wires, etc.) But it is also important to understand how antenna towers when flying your drone.
Most of the time, these antenna towers for radio and television will be pretty obvious. What isn’t always so obvious, and can be even more dangerous than the antenna tower itself, are the guy wires that attach to the antenna and extend out to the ground. Guy wires are the wires (pictured below), that extend outwards from a tower (sometimes as much as 1,500 feet from the tower itself). I always thought it was called a “guide” wire, but I stand corrected. The FAA clearly calls them “guy wires.” We’ll go with that.
To add another complication, if you are flying near an antenna with guy wires near dusk, the wires themselves can be almost impossible to see. The FAA recommends staying at least 2,000 feet away from a tower, but, if you are there to inspect it, this may not be possible. So, if you are near antenna towers when flying your drone at dusk, either re-schedule the shoot or be sure you can adequately see the antenna tower and all guy wires.
Lastly, just be aware that new antenna towers can pop up and may not yet be included on a sectional.
Picture courtesy of Mario Caruso
Use common sense and visually inspect the area where you will be flying before taking off. One thing I’ve done when on site is locate the guy wires on the antenna and fly vertical passes between the wires, which allows you to completely avoid them. For more information about how to know the height above ground level (and mean sea level) of an obstacle, including antenna towers, see my guide on how to read a sectional chart.
