Why Do Private Jets Fly So High Compared To Commercial Airliners?

Airplanes cruise at altitudes of several thousand feet above the ground for most parts of their journeys. If the sole purpose were to avoid buildings, airplanes wouldn't need to fly above 3,000 feet — even the Burj Khalifa could be avoided at that height. However, commercial airliners typically cruise at around 35,000 feet, and private jets can go even higher up to 51,000 feet.

The high cruising altitude for planes isn't meant for avoiding obstacles on the way but an optimal way to minimize fuel consumption for the entire flight. If you've been on a mountain trek, you would have realized the air starts thinning as you climb. As air is denser closer to the ground, airplanes burn significantly more fuel while flying low. To enjoy reduced drag and subsequently reduced fuel consumption, airplanes cruise at thousands of feet above sea level.

However, if flying high has such crucial benefits, why don't commercial airliners fly as high as private jets? Additionally, do private jets fly higher just for better fuel economy, or is there more to the story?

A commercial airliner is designed to carry passengers, their baggage, and necessary fuel efficiently from point A to B. For this, commercial airliners are designed to carry more payload but have a lower power-to-weight ratio when compared to a private jet. This comparatively lower power-to-weight ratio limits how quickly airliners can climb, with most airliners having a ceiling height of around 41,000 to 43,000 feet. Private jets, on the other hand, are built for an entirely different purpose; they are designed to carry significantly less payload and typically have a higher power-to-weight ratio, allowing them to climb altitudes close to 50,000 feet much faster.

Think of a commercial airliner as a bus; it can hold a large number of people and their baggage. In contrast, a private jet is like a car; it carries less load but is much faster. While a commercial cannot go above a certain speed and needs time to reach its maximum speed, a jet can typically gain altitude much faster and reach higher speeds. That said, let's look at what benefits private jets enjoy cruising higher than their commercial counterparts.

Although it might seem airplanes have the entire sky to themselves while flying, they have to follow predefined paths while flying. As these paths are designed to optimally fly the plane to their destination, planes need to follow these invisible highways in the sky. Busy flying routes can have significant traffic, causing airplanes to constantly change their altitude and speeds in accordance with air traffic control.

Private jets can take more direct, faster routes as they enjoy the unparalleled convenience of flying higher than commercial airliners. Less air traffic for private jets typically results in faster flying times. Moreover, private jet passengers often enjoy shorter security lines and special terminals.

Apart from this, private jets are better able to dodge bad weather due to their ability to fly at high altitudes. Commercial airliners flying in congested airspaces might find it harder to switch to a different route and dodge bad weather.

Remember how air becomes thin with an increase in height? Less dense air also makes it easier for planes to fly faster while using less fuel. As private jets already have a higher power-to-weight ratio, when paired with high-altitude cruising, private jets become significantly faster than commercial airliners.

Apart from this, flying higher than commercial airliners has some added benefits. First up, pilots get more time to find a way out in case of an emergency, which can make private jets safer than commercial airliners, as every extra foot in altitude translates to more time the jet can be airborne. Moreover, high-altitude flying translates to less noise inside the aircraft cabin, making the private jet experience even more comfortable. Due to being small and more powerful, private jets are more agile than their commercial counterparts, making them better at descending faster and reaching safer altitudes in emergencies like cabin depressurization and emergency landings.

In addition, private jets often experience significantly less turbulence, making for a more comfortable ride. As many of the dangerous weather phenomena typically take place below the 33,000-foot mark, private jets mostly fly unbothered to turbulent weather. Even if a private jet encounters turbulent weather in its path, it can quickly dodge it and change paths due to greater flexibility and agility in the air.