FAR 91.411 — Altimeter System Inspections
FAR 91.411 requires altimeter, static system, and altitude reporting checks every 24 calendar months for IFR flight in controlled airspace. Learn what's required.
In Plain English
FAR 91.411 sets the inspection requirements that must be met before you can fly an airplane or helicopter IFR in controlled airspace. It works hand-in-hand with the transponder check in 91.413 and is one of the items you'll verify during preflight paperwork review.
The rule requires three checks:
- Within the preceding 24 calendar months, the static pressure system, each altimeter, and the automatic pressure altitude reporting system must be tested and found to comply with appendices E and F of Part 43.
- Any time the static system is opened and closed (other than using drain or alternate static valves), it must be retested per appendix E.
- After installation or maintenance on the transponder's altitude reporting system where data errors could be introduced, the integrated system must be retested.
Tests must be done by the manufacturer, an appropriately rated certificated repair station, or — for static system tests only — a certificated mechanic with an airframe rating. You also can't fly IFR above the maximum altitude to which the system was tested. TSO-approved altimeters are considered tested as of their manufacture date.
Regulation Text
14 CFR § 91.411§ 91.411 Altimeter system and altitude reporting equipment tests and inspections.
(a) 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;
(2) Except for the use of system drain and alternate static pressure valves, following any opening and closing of the static pressure system, that system has been tested and inspected and found to comply with paragraph (a), appendix E, of part 43 of this chapter; and
(3) Following installation or maintenance on the automatic pressure altitude reporting system of the 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.
(b) The tests required by paragraph (a) of this section must be conducted by—
(1) The manufacturer of the airplane, or helicopter, on which the tests and inspections are to be performed;
(2) A certificated repair station properly equipped to perform those functions and holding—
(i) An instrument rating, Class I;
(ii) A limited instrument rating appropriate to the make and model of appliance to be tested;
(iii) A limited rating appropriate to the test to be performed;
(iv) An airframe rating appropriate to the airplane, or helicopter, to be tested; or
(3) A certificated mechanic with an airframe rating (static pressure system tests and inspections only).
(c) Altimeter and altitude reporting equipment approved under Technical Standard Orders are considered to be tested and inspected as of the date of their manufacture.
(d) No person may operate an airplane, or helicopter, in controlled airspace under IFR at an altitude above the maximum altitude at which all altimeters and the automatic altitude reporting system of that airplane, or helicopter, have been tested.
[Docket 18334, 54 FR 34308, Aug. 18, 1989, as amended by Amdt. 91-269, 66 FR 41116, Aug. 6, 2001; 72 FR 7739, Feb. 20, 2007]
Oral Exam Questions a DPE Might Ask
Q1What inspections are required to fly IFR in controlled airspace under FAR 91.411?
Per FAR 91.411, within the preceding 24 calendar months the static pressure system, each altimeter, and the automatic altitude reporting system must be tested and inspected in accordance with appendices E and F of Part 43.
Q2Who is authorized to perform the altimeter and static system tests required by FAR 91.411?
FAR 91.411(b) allows the aircraft manufacturer, an appropriately rated certificated repair station, or — for static pressure system tests and inspections only — a certificated mechanic with an airframe rating.
Q3If your altimeter system was last tested to 18,000 feet, can you file IFR to FL230 in controlled airspace?
No. FAR 91.411(d) prohibits operating IFR in controlled airspace above the maximum altitude at which the altimeters and automatic altitude reporting system were tested.
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Related Sections in Part 91