Why Don’t Airplanes Fly in a Straight Line to Save Fuel?

Have you ever wondered why airplanes follow a curved path instead of flying in a perfectly straight line on flight maps? Wouldn’t flying straight save fuel?

Everyone knows that the shortest distance between two points is a straight line, and logically, a shorter route means less fuel consumption. However, when looking at flight maps, you will notice that planes fly in a curved path instead of a straight one.

Why Don’t Planes Fly in a Straight Line?

There are several reasons why aircraft do not fly directly from point A to point B. The two main factors affecting flight paths are the Earth’s shape and atmospheric winds.

1. The Earth’s Shape and the Great Circle Route

Since the Earth is spherical and rotates on its axis, the equator is slightly "bulged out," making the circumference at the equator larger than at the poles.

This means that flying towards the poles shortens the distance compared to flying in a straight line along the equator. That’s why flights from the U.S. to Asia often pass over Alaska and Siberia instead of taking what appears to be a straight path on a 2D map. This technique, called the Great Circle Route, helps shorten travel time and saves fuel.

2. Jet Streams and Weather Conditions

Flight paths are pre-planned before takeoff to ensure the shortest and most efficient route. However, planes may adjust their flight path mid-flight depending on weather conditions, wind speeds, and jet streams.

Jet streams are high-speed air currents in the atmosphere, reaching speeds of over 320 km/h (200 mph). If a plane flies with the jet stream, it reaches its destination faster and consumes less fuel. On the other hand, flying against the jet stream requires pilots to adjust their route to avoid excessive fuel consumption.

3. Avoiding Air Turbulence

Turbulence is another factor that influences flight paths. The main cause of turbulence is hot air rising from the ground. Water bodies, such as oceans, retain heat better than land, meaning the air over water is more stable than over land.

This explains why many flight routes are designed to fly over the ocean rather than land, even when a direct path over land seems shorter.

The World’s Longest Direct Flight

Currently, the longest non-stop flight in the world is from Singapore to Newark, New Jersey, USA, covering over 16,700 km (10,400 miles) in about 18 hours and 45 minutes.

Why Do Airplanes Sometimes Climb Back Up Just Before Landing?

Patrick Smith, a pilot and author of the best-selling book Cockpit Confidential, has discussed various passenger concerns about flying. One common fear is why a plane suddenly ascends just before landing.

Smith explains that this maneuver is called a “go-around” and is not an aviation emergency. It is a common safety procedure and happens for a few reasons:

1. Runway Clearance Issues: If another aircraft has not yet vacated the runway, pilots must abort the landing to avoid collision.
2. Poor Weather Conditions: If visibility drops below safe levels during the approach, pilots may need to climb back up and try again or land at an alternate airport.

What Happens If a Plane Suddenly Loses Cabin Pressure?

A dramatic loss of cabin pressure is a common scene in movies, often portrayed as a chaotic and life-threatening event. But what really happens in such a situation?

Smith reassures passengers that while explosive decompression due to a bomb is possible, it is extremely rare. In most cases, cabin pressure loss occurs gradually due to minor leaks.

When this happens:

• Oxygen masks will automatically deploy for passengers to use.
• Pilots will descend to a safe altitude where passengers can breathe normally without oxygen masks.
• Some passengers may experience no.sebl.eeds or ear p.ain, but staying calm and following crew instructions is the best course of action.

Smith emphasizes that there is no need to panic, as aircraft and crew are well-trained to handle such situations efficiently.