29.1323—Airspeed indicating system.
For each airspeed indicating system, the following apply:
(a)
Each airspeed indicating instrument must be calibrated to indicate true airspeed (at sea level with a standard atmosphere) with a minimum practicable instrument calibration error when the corresponding pitot and static pressures are applied.
(b)
Each system must be calibrated to determine system error excluding airspeed instrument error. This calibration must be determined—
(1)
In level flight at speeds of 20 knots and greater, and over an appropriate range of speeds for flight conditions of climb and autorotation; and
(i)
Three percent or 5 knots, whichever is greater, in level flight at speeds above 80 percent of takeoff safety speed; and
(d)
For Category B rotorcraft, the system error, excluding the airspeed instrument calibration error, may not exceed 3 percent or 5 knots, whichever is greater, in level flight at speeds above 80 percent of the climbout speed attained at 50 feet when complying with § 29.63.
(e)
Each system must be arranged, so far as practicable, to prevent malfunction or serious error due to the entry of moisture, dirt, or other substances.
(f)
Each system must have a heated pitot tube or an equivalent means of preventing malfunction due to icing.