# Installation or maintenance on an ATC transponder — Aircraft inspection and test intervals under 14 CFR Part 91

For Installation or maintenance on an ATC transponder, interval is Following any installation or maintenance on an ATC transponder where data correspondence error could be introduced; applies to is ATC transponder where data correspondence error could be introduced; consequence if lapsed is No persons may use an ATC transponder; regulation section is § 91.413, verified against its source on 2026-08-06.

- **Inspection or test item:** Installation or maintenance on an ATC transponder _(verified: appears in the quote below)_
- **Interval:** Following any installation or maintenance on an ATC transponder where data correspondence error could be introduced _(verified: appears in the quote below)_
- **Applies to:** ATC transponder where data correspondence error could be introduced _(verified: appears in the quote below)_
- **Consequence if lapsed:** No persons may use an ATC transponder _(verified: appears in the quote below)_
- **Regulation section:** § 91.413 _(verified: appears in the quote below)_

## What the source says

> No persons may use an ATC transponder that is specified in 91.215(a), 121.345(c), or § 135.143(c) of this chapter unless, within the preceding 24 calendar months, the ATC transponder has been tested and inspected and found to comply with appendix F of part 43 of this chapter; and (b) Following any installation or maintenance on an ATC transponder where data correspondence error could be introduced, the integrated system has been tested, inspected, and found to comply with paragraph (c), appendix E, of part 43 of this chapter.

## Source

- https://www.ecfr.gov/api/versioner/v1/full/2026-08-01/title-14.xml?part=91&section=91.413

Last verified: 2026-08-06. Review by: 2028-08-05.
Part of [Aircraft inspection and test intervals under 14 CFR Part 91](https://referencesource.org/aircraft-inspection-and-test-intervals/).