# Altimeter instrument — Aircraft inspection and test intervals under 14 CFR Part 91

For Altimeter instrument, interval is Within the preceding 24 calendar months; applies to is airplane, or helicopter, in controlled airspace under IFR; consequence if lapsed is No person may operate an airplane, or helicopter, in controlled airspace under IFR; regulation section is § 91.411, verified against its source on 2026-08-06.

- **Inspection or test item:** Altimeter instrument _(verified: appears in the quote below)_
- **Interval:** Within the preceding 24 calendar months _(verified: appears in the quote below)_
- **Applies to:** airplane, or helicopter, in controlled airspace under IFR _(verified: appears in the quote below)_
- **Consequence if lapsed:** No person may operate an airplane, or helicopter, in controlled airspace under IFR _(verified: appears in the quote below)_
- **Regulation section:** § 91.411 _(verified: appears in the quote below)_

## What the source says

> No person may operate an airplane, or helicopter, in controlled airspace under IFR unless— (1) Within the preceding 24 calendar months, each static pressure system, each altimeter instrument, and each automatic pressure altitude reporting system has been tested and inspected and found to comply with appendices E and F of part 43 of this chapter;

## Source

- https://www.ecfr.gov/api/versioner/v1/full/2026-08-01/title-14.xml?part=91&section=91.411

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/).