---
kind: "section"
citation: "14 C.F.R. § 171.9"
title: "14"
number: "171.9"
heading: "Installation requirements."
url: "https://uscodex.org/cfr/14/171.9"
---

# §171.9. Installation requirements.

- (a) The facility must be installed according to accepted good engineering practices, applicable electric and safety codes, and the installation must meet at least the Federal Communication Commission's licensing requirements.
- (b) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated, with a supplemental standby system, if needed.
- (c) Dual transmitting equipment with automatic changeover is preferred and may be required to support certain IFR procedures.
- (d) There must be a means for determining, from the ground, the performance of the equipment, including the antenna, initially and periodically.
- (e) A facility intended for use as an instrument approach aid for an airport must have or be supplemented by (depending on circumstances) the following ground-air or landline communications services:
  - (1) At facilities outside of and not immediately adjacent to controlled airspace, there must be ground-air communications from the airport served by the facility. Separate communications channels are acceptable.
  - (2) At facilities within or immediately adjacent to controlled airspace, there must be the ground-air communications required by [paragraph (e)(1)](#e-1) of this section and reliable communications (at least a landline telephone) from the airport to the nearest FAA air traffic control or communication facility.

## Notes

### Amendments

[Docket 5034, 29 FR 11337, Aug. 6, 1964, as amended by Amdt. 171-7, 35 FR 12711, Aug. 11, 1970; Amdt. 171-16, 56 FR 65664, Dec. 17, 1991]

### Authority

Authority: 49 U.S.C. 106(g), 40103-40107, 40109, 40113, 44502, 44701-44702, 44708-44709, 44711, 44719-44721, 45303, 46308.

### Source

Source: Docket 5034, 29 FR 11337, Aug. 6, 1964, unless otherwise noted.

### Amendments

[Docket 5034, 29 FR 11337, Aug. 6, 1964, as amended by Amdt. 171-7, 35 FR 12711, Aug. 11, 1970; Amdt. 171-16, 56 FR 65664, Dec. 17, 1991]