A C-130 is flying in standard sea-level conditions at a true airspeed of 200 knots. What is its flight Mach number? First, convert true airspeed in knots to feet per second using the conversion factor on page 569 of the textbook. Then, find the speed of sound at sea level in the standard atmosphere on page 564 of the textbook... Finally, divide the true airspeed by the speed of sound and select your answer from the list below by clicking on the appropriate letter.