§3.663 Air-speed indicating system.

This system shall be so installed that the air-speed indicator shall indicate true air speed at sea level under standard conditions to within an allowable inStallational error of not more than plus or minus 3 percent of the calibrated air speed or 5 miles per hour, whichever is greater, throughout the operating range of the airplane with flaps up from V- to 13 V;, and with flaps down at 13 V,,. The calibration shall be made in flight.