I still remember the first time I got to fly in a small aircraft and I was stunned just how close all the towns were that I had been driving around for years. What took an hour to go from one town to the next now took just a matter of 10 to 15 minutes in an aircraft! It was at that point this flying bug grabbed me and wouldn’t let go!
However, once my flight training began, learning how to navigate in the air was a real undertaking! In a car it’s easy, you just follow the signs by the side of the road, but in the air, a pilot has no signs so how do they know where to go!?
Today, pilots navigate using GPS-based systems in their aircraft. They fly between imaginary vertical points known as waypoints that are stored in the aircraft GPS database. Before GPS, pilots had to fly magnetic headings and timed legs or use radio navigation beacons to give the pilot position information via basic instruments in the cockpit.
There are many forms of navigation techniques that pilots have at their disposal. Some of those techniques are very basic and some used advanced technology but once a pilot has learned how to use each technique getting from point A to point B is easy peasy.
However, cutting corners in the flight planning or not flying accurately can soon have a pilot lost, and having been lost before, it is a gut-wrenching feeling until you find something on the ground that you recognize on your map.
With modern navigation avionics utilizing GPS and moving digital maps, piloting an aircraft has never been easier. I dread to think how difficult it must have been for someone like Emelia Earhart navigating around the globe on the most primitive of instruments, but she did it! That was real piloting!
Types of Aviation Navigation
There are many ways to get an aircraft from point A to point B and depending on the type of flight the pilot is conducting they may use one or multiple techniques listed below:
For pilots that live in the area in which they are flying around, they will instantly know of their position by looking out of the window, recognize the area and be able to get to where they are going without any difficulty. Many police and news helicopters use this technique when flying over a city. This obviously requires the local knowledge mixed with the next technique – Pilotage.
Pilotage is the technique of looking out of the aircraft window and either flying by reference to local landmarks with local knowledge or by taking what the pilot sees and referring to a map to locate their position. Mountains, monuments, roads, rivers, rail lines, and towns all make for great points of reference for the pilot to find on their map to allow them to compute their position in relation to them.
This technique is based on flying a set heading for a set time to reach a set landmark. For instance, if an aircraft is flying at 120kts (Knots) on a calm day the aircraft will cover 2nm (Nautical Miles) every minute. Therefore if the pilot wants to reach an airport that is 60nm west of them, they can fly on a heading of 270° for 30 minutes and they should be over the destination airport.
The trick is to compensate for the wind blowing the aircraft off course or altering the timing because of a headwind slowing the speed of the aircraft over the ground or a tailwind pushing them faster.
A 20kt tailwind (Wind giving them a push) will make the aircraft travel over the ground at 140kts even though the pilot’s airspeed gauge is reading 120kts. This will mean the aircraft will cover 2.3 miles every minute and will cause the aircraft to reach its destination sooner.
Navigation beacons are located on the ground all over the world. Each beacon has its own radio frequency and when the pilot tunes their navigation radio to the individual beacons radio frequency it will show the pilot the beacon’s location in relation to the aircraft.
The simplest way to navigate using beacons is by pointing the aircraft towards the beacon and flying to it, this way the pilot can navigate from beacon to beacon to get to their destination. There are much more complicated ways using beacons but they are for their own article!
GPS & Waypoints
Just like the GPS you have in your car, an aviation GPS allows the pilot to either enter a set of latitude and longitude coordinates and the GPS will paint a line on its screen for the pilot to follow to reach that location, or
The world/country is covered in GPS waypoints that are created by that countries aviation controlling authority. These imaginary points are located everywhere and each one is given a 5 letter name. The pilot can then create a route by flying to each waypoint to take them to their intended destination. This is how the airline world navigates.
Most of the popular routes via waypoints will have a dedicated Airway between them. These ‘Victor Airways’ are given a number and usually contain minimum altitudes to fly that route section.
Air Traffic Control Vectors
Most aircraft are equipped with a device called a ‘Transponder’, it allows the air traffic controller to see that particular aircraft on their radar screen. The controller is then able to instruct the pilot over the radio which way to turn or what altitude to climb/descend to allow them to navigate. These directional commands given by ATC are known as Vectors
For Example: “United 63 turn left heading 320, climb 5000”
This tells the pilot they need to turn to the left until they are facing 320° and climb up until they reach 5000ft then level off.
Vectors are used to get aircraft lined up for landing at all busy airports. When planes are coming in from all directions, the ATC controllers will funnel all the aircraft to one waypoint many miles out from the airport and then have them all lined up for landing.
Learning Basic Aviation Navigation Techniques
Just like all life skills, every pilot must first learn the most basic techniques of air navigation before they move onto the advanced, modern day forms. The main reason behind this is if a pilot was to lose all electrical power, along with their navigation displays they can pull out a map and get plotting a path to their destination. This is mainly for the general aviation pilot who is out flying around for fun and recreation in simple aircraft. The redundant systems in most airliners and commercial aircraft make losing all navigation equipment pretty much non-existent!
When every pilot first begins learning to fly these are the navigation fundamentals they must first master:
Any pilot who is flying a small aircraft under VFR (Visual Flight Rules – Has to see the ground at all times) and is not familiar with an area will need to look at a map to begin understanding where places are in relation to one another. Pilot maps or charts/sectionals as they are commonly referred to contain a whole bunch of information that the pilot uses to help navigate as they look for landmarks out of the window.
Many of the common items on aviation charts include:
- Towns & Cities
- Roads, Rivers, Rail Lines & Powerlines
- Tall Structures like Radio Towers or Wind Turbines
- Topographical Terrain Shading
- Highest Peaks
- National Parks
- Airports, Airstrips & Heliports
- Navigation Beacons & Aviation Routes
- Airspace Types & Boundaries
- Radio Communication Frequencies
- Latitude & Longitude
When flying around, pilots need to develop the skill to be able to look out of their windows and reference landmarks on the ground to their placement on the chart. This is a very useful way to ensure they are on their planned route and passing that landmark at the specified time. This is known as Pilotage.
Although not used by most pilots outside of the training environment, having a chart of the area and drawn route the pilot wishes to fly close to hand is always a good idea. To this day I still have a chart next to my seat and being in a helicopter it makes it easy to set down on a hill or mountain and formulate a plan if I were to lose my GPS data and I was in unfamiliar territory.
The chart is the first point of reference a pilot should use when building a route of their next flight – That building of a route is called the Flight Plan.
As mentioned, Pilotage is flying the aircraft and referencing the aircraft’s position to things the pilot sees out of the aircraft. It is easy for a pilot to use this technique when there are highly visible and identifiable landmarks like mountains, stadiums, monuments, etc but it becomes a little more difficult when the pilot starts to get into the rural parts of the country.
It takes some practice to be able to identify lakes, railroads, and hills when that is all you see. The trick is to look for things that stand out like where roads or rail lines cross a river, or when powerlines take a turn. Odd shaped lakes next to hills or mountains etc. A trick that I find useful is once you are aware of your position on the chart, put your finger there, and turn the chart so it faces the way you are flying. If the next thing coming up on your map is a road crossing a river, you should be able to see it out of the window.
Pilotage takes practice and from time to time all pilots should get the sectional out, turn off their GPS, and practice this technique!
Once the aircraft is in flight and the flight plan is being flown, the pilot must begin to start timing their legs and flying their planned headings. If the flight planning stage was accurate the pilot should be seeing and crossing their chosen landmarks at the times noted on the flight plan. With the use of good Pilotage skills, the pilot can ensure the route being actually flown is matching the route that was planned on the chart and is progressing as it should.
If it is taking longer than planned to reach the planned landmarks, fuel or daylight could become a problem, especially if the flight is a long cross-country trip!
Having spent a good amount of time planning the flight, it is no good if the aircraft is not flown according to what was planned. Each leg will have been planned for the aircraft to fly at a set speed, on a set heading for a set time and a set altitude. If just one of those parameters is off then a pilot can quickly become unsure of their position.
It takes great skill and self-discipline to fly at set parameters!. I find as pilots get further into their experience these basic fundamentals of flying become forgotten and pilots seem to get lazy and fly as they wish! I’ve seen 5000 hour pilots who could not maintain an altitude to within +/-300ft! They were terrible, whereas a proficient pilot should be mad if they cannot maintain an altitude within +/-50ft!
If the flight plan requires the aircraft to be flown at 100 knots on heading 270° at 4000ft for 23 minutes then the pilot should be doing their best to keep those numbers. When the aircraft starts to wander from those parameters then more work is required by the pilot to get back to where they are supposed to be and the longer they leave the correction, the further off course or plan they will be!
For most pilots, being off course by a few degrees or behind schedule a few minutes is acceptable, but if a pilot becomes unsure of their position it is easy for an aircraft to wander into restricted or busy airspace which could result in not only getting yelled at by ATC but could end up with the pilot being fined or prosecuted!
Good airmanship requires accurate flying discipline.
In-Flight Corrections for Wind, Weather
Forecasted weather is just the weather readers best guess and sometimes they get it slightly off. It is hard to judge exact metrics like wind speed and direction, yet both of those can have a very dramatic effect on how an aircraft flies.
When a pilot starts to see large differences between the planned landmark crossing times and the actual crossing times, the mental math has to begin. If the wind is stronger than planned and the aircraft is constantly being blown off course, a heading correction needs to be applied to ensure the aircraft begins to travel over the ground on its chosen path and remains there!
In flight corrections happen all the time and some need a good bit of mental math to figure out whereas some can be flown without much hassle. The trick to inflight corrections is to make them early enough as the error compounds the longer the flight continues. A small 5° correction 2 miles into a flight can prevent the aircraft from being almost 10 miles off course by the time they reach 100nm away!. This is where good pilotage, dead reckoning, and accurate flying skills really help!
Pilots are constantly making decisions and calculations to ensure flight safety and one of the hardest skills to develop when navigating an aircraft is knowing when to land or turn around when the weather begins to worsen.
Many accidents have occurred in general aviation because the pilot had ‘Get-Home-I-Tus’ and continued flying into poor weather conditions rather than chose to land and wait it out. Thunderstorms, fog, mist, heavy rain, nightfall, snow, reducing cloud ceilings are all hazards that pilots need to monitor during the flight in case they need to adjust their plan and divert around the weather or land before its too late.
Even yesterday, I landed in the middle of nowhere with the customer as an unforecasted wall of fog in front us said it was time for a coffee break! 30 minutes later, the sun had burned it off and we continued with our days work.
It is always better to be on the ground wishing you were flying than flying and wishing you were on the ground!
Advanced Aviation Navigation
Once the basic skills of aviation navigation have been learned the pilot then steps into the real world. One which is ruled by the Global Positioning System – GPS.
Today’s modern aviation GPS units are fantastic and even the small portable units are very powerful, accurate, and affordable. Once out of flight school this will be the only way a pilot will navigate, but they need to have the knowledge of the basics in case the GPS decides to not work, and trust me when its -30°F GPS units can be like my 6-year old daughter and not cooperate!
Most of us have all used a GPS either in the car for finding your way around an unfamiliar city or out hiking, and for aircraft the GPS does the same thing except it will tell the pilot the aircraft’s location (usually by showing its position on a moving digital map), where it is programmed to go to, how long it is going to take to get there, how fast it is moving over the ground, etc, all while displaying this information over this digital map. The most basic GPS units have no map but just show a number of what heading to fly and how far the unit is from the desired location.
On the other end of the spectrum, aircraft can have GPS units with full moving maps, terrain, airspace, runway approach procedures, and even what is known as Synthetic Vision. This is when the GPS uses the terrain data in its database to construct and depict a 3D image of the terrain and world that is approaching! They are pretty cool but can be expensive!
A stroll around an airshow or flying club flightline will reveal pretty much every aircraft has a GPS unit of some form inside. Some may be built into the screens and avionics mounted into the cockpit dashboard, some may be portable units that sit in a cradle on top of the cockpit panel, and now some are even iPads running an incredible software known like ForeFlight.
Once a GPS has the destination entered by the pilot it is just a matter of flying up the magenta line shown on the screen until they reach that destination. It will show the pilot exactly where they are at any time and tell them how long they have to go until they get there. It really is impossible to get lost using a GPS providing the pilot puts in the right destination to begin with!
Here is the portable GPS I’m currently flying within the company helicopter. It the Garmin Aera 660 touchscreen and its very good. My own portable GPS is a Garmin GPSMap 296 and even after 15 years it still fires up every time I need it! Unless it is -30°F and then it thinks about it!
If you would like to find out more information on the Garmin Aera 660 aviation GPS unit you can find it HERE at Amazon.com
For many pilots not flying an airliner the advent of ForeFlight for the iPhone & iPad has been a game-changer in the general aviation industry. Initially developed by two pilots in 2007 it was then bought by Boeing who also owns the world’s most popular aviation navigation publications – Jeppesen.
This software uses either the onboard iPad GPS receiver or an externally mounted GPS to feed location data into the iPad and show the aircraft’s position on the Jeppesen publications!. For $140/year any pilot can have a full moving map GPS with overlaid weather, traffic, and instrument approach procedures among many, many other features! ForeFlight itself warrants its own article!
Loading routes or selecting them while inflight is a breeze and the designers of ForeFlight have sat down with many pilots to design this to be one of the easiest, yet most powerful portable GPS, moving map software available.
Not only does ForeFlight offer the navigation information, with monthly updates it will display all the current information about airports, heliports, NOTAM’s, airspace changes, and inflight weather data. It truly is a great software and if you are new to aviation I highly recommend you check it out!
FMS, Autopilots & Flight Directors
When aircraft begin to get larger and are used primarily to fly in and above the clouds, then automation really steps up to the plate. Most modern airliners, corporate & private jets, and larger helicopters will have a complete avionics package that includes multiple GPS units, radios, engine & aircraft parameter monitoring, flight directors, autopilots, and much more.
These integrated suites will use an FMS (Flight Management System) to allow the pilot/s to input a published Airport Departure Procedure and routing predetermined by their company dispatchers/flight planners. Once the aircraft has taken off and the pilots select that the aircraft begins automated navigation, the FMS will then take data from the integrated GPS and local radio navigation beacons and then inputs the selected navigation route data into the autopilot system to move the aircraft control surfaces and make the aircraft follow the selected route.
This high level of automation makes it really simple for the pilots to fly the aircraft very accurately. Using the FMS to control the flight path, the pilots then just need to input the desired altitude and airspeed into the aircraft ‘Flight Director’ and the aircraft will follow as requested. Once it comes time to begin an approach into an airport the pilots will select an Instrument Approach Procedure from the FMS database and once cleared by ATC for the approach, the pilots activate the FMS to fly the approach and sit back until its time for touch down!
Garbage In Garbage Out
One of the many problems with advanced navigation automation is that it will do EXACTLY what the pilot has told it to do. If the pilot inputs the wrong data, destination, waypoint or intersect then the aircraft will do it, which can come to a surprise to the pilots when the aircraft does something it is not supposed to!
When I first moved into a modern helicopter with automation and an FMS system it was a steep learning curve and it was very easy to make a mistake, especially when programming a complex route! Luckily it was all in the simulator so we just reset and started again, but it really shows that no matter what kind of navigation system or technique a pilot is using, if the data is wrong or the pilot makes a mistake the results can really send the blood pressure rising!
The advances in GPS technology have allowed pilots to navigate much easier and safer and I can tell you that from personal experience that navigating with a GPS makes getting from point A to point B a simple task. Having the basic navigation fundamentals in my arsenal is always a nice feeling to have knowing that if the technology fails I will still be able to find my way around and make it to the destination.
As technology advances it will be an exciting time to see what navigation inventions find their way into the cockpit. In the meantime, GPS is working just fine to allow everyone in the air to know where they are and which way to fly to get home!
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