##### Speed of Sound The speed of sound at [[MSL|sea level]] under standard temperature and pressure conditions is 1,108 feet per second or 658 knots. [[Mach number]] refers to the ratio of the speed of an aircraft to the speed of sound. >Covered in: >Mentioned in: >References: [[AMT General Handbook Ch5_3#Speed of Sound|📘]] >Required by: > >Related to: