Pilots use a range of sophisticated navigational equipment and techniques to know where to fly and reach their destinations.

The most commonly used navigational system is aviation GPS, but pilots sometimes also use other techniques like landmark spotting, navigational beacons, and dead reckoning.

Air traffic control provides pilots with navigational instructions during navigational instrument failures or difficult weather conditions, letting planes fly and land safely.

How Do Pilots Know Where to Fly? (5 Methods)

Landmark Knowledge/Pilotage

Pilots familiar with the area they’re flying in can instantly recognize landmarks through the windshield and know their position. This technique is called ‘pilotage.’

These landmarks include mountains, rivers, valleys, canyons, and notable artificial landmarks like statues and monuments.

These landmarks are excellent for computing the plane’s position on a map.

Pilots use these landmarks as reference points on maps to figure out their position and the distance from their destination. 

Dead Reckoning

Dead reckoning is when pilots head towards a predetermined destination in a set time.

For example, if a plane is flying at 120 knots in clear weather, it will travel 2 nautical miles per minute.

Consequently, if the aircraft’s destination is 60 nautical miles away, the plane will fly in its direction for 30 minutes.

When using dead reckoning, it’s important to note weather conditions, since bad weather slows down cruise speed.

Navigational Beacons

Navigational beacons are located across the world, with every beacon having a unique radio frequency for identifying it.

Pilots tune their navigation radio to each beacon to receive location data.

The most common way of using navigation beacons is to point the plane in the beacon’s direction and fly over it.

Some airlines also use more complicated forms of navigational beacons. 

GPS & Waypoints

Aviation GPS is the most common form of navigation for planes and now the standard method of how pilots know where to fly.

Planes have aviation GPS systems similar to the ones in your cars.

Pilots enter location data consisting of latitude and longitude coordinates, and the GPS provides a map guide.

The GPS will draw a line on the screen showing the best route to the destination.

Since the world is covered with GPS waypoints built by every country’s aviation authority, GPS aviation is a common and efficient aviation navigation technique. 

Air Traffic Control Vectors

Most aircraft have transponders, which are devices that let them communicate with Air Traffic Control (ATC).

Air traffic controllers use transponders to determine aircraft location on radar. Air traffic controllers then provide navigational instructions to pilots, including what direction to turn to and what altitude to fly.

These navigational commands are called ‘vectors.’

Vectors are primarily used to assist with aircraft landing.

Air traffic controllers will issue vectors to multiple aircraft in busy airports and funnel them into a waypoint a mile from the airport before granting landing permission. 

Related: What Does an Air Traffic Controller Do?

How Has Flight Navigation Progressed Over the Years?

When flight was in its infancy, pilots knew where to fly by simply relying on individual sight for navigation.

Pilots would look out from their cockpits and use their best estimations for their location to land. Often they’d sight landmarks or use automobile maps. Early pilots primarily flew during the daytime for this reason.

The Post Office began building a transcontinental aviation beacon system in 1923. They built beacons on towers spaced between 24-40 km / 15 to 25 miles. Each beacon would have enough candlelight to be visible for 64 km / 40 miles in clear weather.

While this measure helped pilots under ideal conditions, it became necessary to develop new on-plane navigational technology to navigate high altitudes under difficult weather.

The high-precision polar gyro was specifically developed to help pilots chart routes using a grid map at high altitudes over arctic areas.

Soon, ships also began to assist aircraft navigation by providing pilots with radio instructions.

Other aircraft navigational developments include the Star Altitudes Curve, an astronomical chart system.

Following the Second World War, the Civil Aviation Authority employed the aforementioned navigational beacons for commercial use.

In 1961, The Federal Aviation Authority (FAA) introduced distance-measuring equipment for the entire aviation system. The system lets aircraft determine their position by calculating their distance from checkpoints. 

By 1969, pilots adopted 16 set area navigation routes instead of depending on ground-based radio navigation.

These navigational routes use invisible lines called radials that represent the aircraft’s position and distance from the destination. A computer on board the plane would assist with navigation.

The FAA introduced the free-flight concept, allowing pilots to choose their own routes instead of depending on pre-set routes.

In the past few decades, aviation GPS via satellites was introduced, and it remains the dominant aircraft navigation tool today. 

What Can Pilots See When Flying?

Pilots see astronomical bodies like the sun, stars and moon, in addition to other aircraft and landmarks like mountains, hills, and rivers.

Typically, pilots cannot see buildings because they’re not detailed enough to be recognized from high altitudes. 

How Can Pilots Navigate or See At Night?

For high altitude flights during the night, airplanes primarily depend on air traffic control, radar, and aircraft navigational instruments.

For low-altitude flights, planes will also depend on city lights, which improve visibility at night.

To prevent collisions, tall buildings often display red warning lights that alert pilots.

Related: How Do Pilots See At Night?

How Do Pilots Know When to Descend?

Aircraft navigational instruments inform pilots when to descend.

These instruments calculate a value known as TOD (top of descent), which shows the optimal descent location.

Pilots also have their descent courses chartered or use visual identifiers and GPS systems for successful landings. 

How Do Pilots Know Where the Runway Is?

Pilots know where the runway is in various ways:

  • GPS and radio navigation systems inform pilots of runway locations.
  • Approach lighting systems on the runway help pilots identify runways at night or during cloudy weather.
  • Low-instrumentation planes use Visual flight rules(VFR).
  • The FAA provides pilots with a detailed directory containing runway locations of all airports on earth.
  • Pilots use VFRs to orient their planes appropriately to the runway’s location. 

In conclusion, pilots know where to fly by using various navigational techniques ranging from spotting landmarks, receiving instructions from air traffic control, and using GPS.

Pilots depend on air traffic control if all these equipment and techniques fail because of bad weather or instrumental problems.