A U-2 Dragon Lady spy plane in flight circa 2022. The U-2 and its successor, the SR-71 Blackbird, are two of the highest-flying aircraft in US history, although flight at their altitude ceiling is extremely technically challenging. (Shutterstock/ranchorunner)

Why Is It So Hard to Fly Planes at High Altitudes?

Share this link on Facebook

Share this page on X (Twitter)

Share this link on LinkedIn

Share this page on Reddit

Email a link to this page

Most civilian planes do not need to regularly fly at the highest altitude they physically can—but this is sometimes the case for the US Air Force.

Of the many planes that have passed through the US Air Force’s arsenal over the decades, the two that have been the hardest to fly are generally agreed to be the U-2 Dragon Lady and SR-71 Blackbird reconnaissance aircraft.

The two planes could not be more different at first glance. The U-2 is an ungainly subsonic aircraft, with a narrow fuselage and extremely long wings. The Blackbird is its opposite, with a wide body, narrow wings, and an enormous turbojet engine on either side—closer in appearance to a science-fiction spaceship than a typical fighter jet. Yet in spite of their obvious differences, the U-2 and the SR-71 have something important in common: both are designed to operate at extraordinarily high altitudes of 70,000 to 80,000 feet (21,330–24,380 m), making it far harder to fly them than a typical aircraft.

What Is Considered High-Altitude Flight?

In general, the more technically sophisticated an aircraft is, the higher in the air it can fly.

A typical small civilian propeller plane like a Cessna or Beechcraft will top out at around 15,000 feet. Civilian commercial aircraft like a Boeing 737 or Airbus A320 have service ceilings at around 40,000 feet, though they tend to cruise........

© The National Interest