Pilotage is a navigational technique used by pilots to determine their plane’s position while flying by referencing landmarks or checkpoints on the ground against a map.

Pilots are trained to read maps, memorize routes, and even list the altitudes from which different checkpoints and landmarks are visible.

Pilotage is employed when a pilot is flying in good visibility conditions that let them see the ground below.

Dead reckoning is another common navigational technique, which is when a pilot uses a compass and the flight’s information to perform calculations to determine the plane’s location and trajectory.

Dead reckoning is used under poor visibility conditions, unlike pilotage. 

What Does Pilotage Mean in Aviation?

Pilotage is navigating by reference to landmarks and checkpoints over the land.

These checkpoints usually include noticeable physical landmarks such as rivers, valleys, mountains, and coastlines. 

How Does Pilotage Work?

Pilotage works with the following five steps.

1. Map Preparations

The pilot finds and marks suitable checkpoints on the map.

The pilot will often plot tracks that frequently involve arcs between the checkpoints.

Special care will be given during this process to ensure that the selected route avoids danger areas and controlled airspace.

2. Map Reading (Clock, Chart, Terrain)

Pilots normally plan ahead, so they can read the map in real-time during the flight.

They’ll use minute marks to note which places to pass at specific time intervals.

3. Points of Reference

The selected route should be studied in reference to its topography.

For example, a pilot will note important geographical features like mountains, rivers, and streams. 

4. Checkpoints Enroute

Pilots will list the associated distances from all checkpoints while flying.

Naturally, the higher the plane is, the harder it is to spot checkpoints and landmarks on the ground.

So pilots list what they can see from different altitudes.

They will also calculate their estimated time of arrival (ETA) accordingly.  

What is the Difference Between Pilotage and Dead Reckoning?

Pilotage is when a pilot reads a map and compares it with their surrounding terrain.

Dead reckoning is when a pilot attempts to learn their current location using a compass and the plane’s known initial location. 

When is Pilotage Used?

Pilotage is used when over an area with good visual meteorological conditions, at higher altitudes, and can also be used at night.

When is Dead Reckoning Used?

Dead reckoning is used during visually poor conditions when the pilot can’t easily spot landmarks on the ground, and at lower altitudes.

How Does Dead Reckoning Work?

A pilot will employ dead reckoning as a form of navigation by relying on the following:

1. The Navigation Log

The navigation log contains information about the flight’s distance, the fuel needed to cover the flight, and ETA.

The pilot regularly adjusts the log and recalculates the ETA.

To use the navigation log, the pilot needs information, including the true airspeed, the distance between the take-off and landing destinations, and the compass heading. 

The pilot will also note weather-related information, like air pressure, temperature, cloud bases, etc. 

2. Plotter

The pilot will use the plotter to determine the plane’s true course and distance. 

3. Compass

A compass is needed for directional purposes. 

4. Course Calculations

Pilots will perform multiple calculations while employing dead reckoning to ensure they fly their desired route.

Specifically, they use the 1 in 60 rule, which states that a plane will fly 1 mile off track after flying 60 miles if it steers 1° off track. 

If the plane flies off its intended route, the pilot will calculate the tracking error, which is the angle at which it needs to fly to correct its course.

They’ll then shift their course by the tracing error and return to their desired route. 

To reach their destination, a pilot will also need to calculate a closing angle to arrive at the right destination at the right time. 

In conclusion:

  • Pilotage is the practice of spotting landmarks and checkpoints on the ground and corroborating them with a map while flying.
  • Pilotage is a complex skill that requires pilots to learn their routes, memorize important checkpoints, and memorize the distance of checkpoints at different altitudes.
  • During pilotage, the pilot will attempt to spot these checkpoints against a map.
  • Pilotage is employed during high visibility conditions.
  • In contrast, dead reckoning is when a pilot uses a compass, known flight data, and a set of calculations to determine their plane’s position and how to return to the intended route if the plane deviates from it. 

Helen Krasner holds a PPL(A), with 15 years experience flying fixed-wing aircraft; a PPL(H), with 13 years experience flying helicopters; and a CPL(H), Helicopter Instructor Rating, with 12 years working as a helicopter instructor.

Helen is an accomplished aviation writer with 12 years of experience, having authored several books and published numerous articles while also serving as the Editor of the BWPA (British Women Pilots Association) newsletter, with her excellent work having been recognized with her nomination of the “Aviation Journalist of the Year” award.

Helen has won the “Dawn to Dusk” International Flying Competition, along with the best all-female competitors, three times with her copilot.