two pilots sitting inside plane

MIAMI – I receive many direct messages from aspiring young Aviators, asking if mathematics is important to become a pilot.

Most pilots would say “No,” because we joke that “you only need your 3 X table.” This is because most airliners descend on a 3 x height vs distance equation.

For example: If you’re cruising at 40,000 feet, you need about 120 miles to descend to your destination. Passing 20,000 feet, you’ll need about 60 miles and 10,000 feet at 30 miles. If you’re 9 miles from the runway, you should be about 3000 feet.

99% of airport approaches around the World are designed for a 3° descent angle. This works out at about 320 ft/nm (feet per nautical mile), but 3X makes the Maths easy, plus it gives you some flex to decelerate during the descent. However, the real answer regarding Maths is “Yes.”

When flying in Russian or Chinese airspace, we fly metric altitudes. MC-21 cockpit. Photo: Irkut

Conversions among Conversions

A practical level of mental arithmetic is important because every flight requires pilots to convert many different units of measurement. Altitude is measured in feet, but when flying in Russian or Chinese airspace, we fly metric altitudes. We measure our altitude in mb (millibars) when flying in Europe, Africa, and most of Asia, but the altitude in the US and Japan is based on inHg (inches of mercury).

Runway distances are measured in meters in Europe and in feet in the US. Visibility is also measured in meters, kilometers on the East side of the Atlantic, or feet and stature miles in the US. Wind speed is measured and reported in knots (nautical miles per hour) in most of the world, but m/s (meters per second) in China, Russia, and a few other countries.

Jet A1 fuel is ordered and delivered in either liters or US gallons and sometimes imperial gallons. We then need to convert the weight of that fuel, into kg (kilograms) if you’re flying an Airbus or lbs (pounds) for a Boeing. Airbus use temperatures in Celsius and Boeings prefer Fahrenheit, plus jet engine oil is delivered and measured in quarts?

A knowledge of Trigonometry and Algebra is useful to get you through the various commercial license exams and there are plenty of excellent phone apps that can make these conversions, although a practical level of mental arithmetic, is essential to keep you safe.

Featured image: Rafael Cosquiere on