---
kind: "section"
citation: "14 C.F.R. § 27.1323"
title: "14"
number: "27.1323"
heading: "Airspeed indicating system."
url: "https://uscodex.org/cfr/14/27.1323"
---

# §27.1323. Airspeed indicating system.

- (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) The airspeed indicating system must be calibrated in flight at forward speeds of 20 knots and over.
- (c) At each forward speed above 80 percent of the climbout speed, the airspeed indicator must indicate true airspeed, at sea level with a standard atmosphere, to within an allowable installation error of not more than the greater of—
  - (1) ±3 percent of the calibrated airspeed; or
  - (2) **Five knots.**

## Notes

### Amendments

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-13, 42 FR 36972, July 18, 1977]

### Authority

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701-44702, 44704.

### Source

Source: Docket No. 5074, 29 FR 15695, Nov. 24, 1964, unless otherwise noted.

### Amendments

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-13, 42 FR 36972, July 18, 1977]