Final answer:
Pilots should maintain their speed within plus or minus 0.02 Mach number or 10 knots of specified speeds for safety and efficiency in controlled airspaces.
Step-by-step explanation:
Pilots complying with speed adjustment instructions should maintain a speed within plus or minus 0.02 Mach number or 10 knots of the specified speed. This is to ensure that aircraft stay within safe operating speeds and also help in maintaining the organization and efficiency of air traffic. The Mach number is a dimensionless unit that describes the ratio of the speed of an object moving through air to the speed of sound in that medium. A speed adjustment within plus or minus 0.02 Mach number allows for a tight tolerance in airspeed, which is crucial for the safety and predictability in the controlled airspace, especially in congested areas or when navigating through turbulent weather conditions.