Yliäänilentoon

Yliäänilentoon refers to flight exceeding the speed of sound. The speed of sound is approximately 343 meters per second (767 miles per hour) at sea level and 20 degrees Celsius (68 degrees Fahrenheit), but it varies with temperature and altitude. When an aircraft travels at or above this speed, it creates a shock wave. This shock wave is a phenomenon associated with compressible flow and is perceived on the ground as a sonic boom.

The transition through the sound barrier, known as transonic flight, is a complex aerodynamic regime. At these speeds, airflow can become a mixture of subsonic and supersonic regions around the aircraft. This can lead to significant changes in lift, drag, and control effectiveness, posing engineering challenges.

The first aircraft to officially break the sound barrier in level flight was the Bell X-1 rocket-powered research aircraft on October 14, 1947, piloted by Chuck Yeager. Since then, supersonic flight has become a capability of military aircraft and some experimental civilian aircraft, though it remains less common for commercial airliners due to factors like fuel efficiency, noise pollution from sonic booms, and the technical complexities involved. Research continues into overcoming these challenges and making supersonic and hypersonic flight (speeds five times the speed of sound or greater) more practical and efficient.