Altitude Alerting System

FAR 91.219 Altitude Alerting System

FAR 91.219 requires turbojet-powered civil airplanes to have an operable altitude alerting system. Learn the requirements, exceptions, and oral exam answers.

In Plain English

FAR 91.219 requires that turbojet-powered U.S.-registered civil airplanes be equipped with an approved, operable altitude alerting system or device. This regulation matters because turbojets operate at high altitudes and high speeds, where altitude busts can quickly become serious safety and ATC issues.

The alerting system must:

  • Alert the pilot when approaching a preselected altitude in climb or descent — either with a combined aural and visual signal, or with visual signals on approach plus an aural signal if the aircraft deviates above or below that altitude.
  • Work from sea level up to the airplane's highest approved operating altitude.
  • Allow altitude preselection in appropriate increments.
  • Be testable without special equipment.
  • Accept barometric pressure settings if it uses baro input.

Below 3,000 feet AGL, only one signal (visual or aural) is required. A radio altimeter may be used if the operator has an approved procedure for determining DA/DH or MDA.

Operators must establish procedures for using the system, and crewmembers must comply. Exceptions include experimental aircraft, ferry flights for installation or repair, airworthiness tests, sales demos, and certain foreign-registration ferry and training flights.

Regulation Text
14 CFR § 91.219
§ 91.219 Altitude alerting system or device: Turbojet-powered civil airplanes. (a) Except as provided in paragraph (d) of this section, no person may operate a turbojet-powered U.S.-registered civil airplane unless that airplane is equipped with an approved altitude alerting system or device that is in operable condition and meets the requirements of paragraph (b) of this section. (b) Each altitude alerting system or device required by paragraph (a) of this section must be able to— (1) Alert the pilot— (i) Upon approaching a preselected altitude in either ascent or descent, by a sequence of both aural and visual signals in sufficient time to establish level flight at that preselected altitude; or (ii) Upon approaching a preselected altitude in either ascent or descent, by a sequence of visual signals in sufficient time to establish level flight at that preselected altitude, and when deviating above and below that preselected altitude, by an aural signal; (2) Provide the required signals from sea level to the highest operating altitude approved for the airplane in which it is installed; (3) Preselect altitudes in increments that are commensurate with the altitudes at which the aircraft is operated; (4) Be tested without special equipment to determine proper operation of the alerting signals; and (5) Accept necessary barometric pressure settings if the system or device operates on barometric pressure. However, for operation below 3,000 feet AGL, the system or device need only provide one signal, either visual or aural, to comply with this paragraph. A radio altimeter may be included to provide the signal if the operator has an approved procedure for its use to determine DA/DH or MDA, as appropriate. (c) Each operator to which this section applies must establish and assign procedures for the use of the altitude alerting system or device and each flight crewmember must comply with those procedures assigned to him. (d) Paragraph (a) of this section does not apply to any operation of an airplane that has an experimental certificate or to the operation of any airplane for the following purposes: (1) Ferrying a newly acquired airplane from the place where possession of it was taken to a place where the altitude alerting system or device is to be installed. (2) Continuing a flight as originally planned, if the altitude alerting system or device becomes inoperative after the airplane has taken off; however, the flight may not depart from a place where repair or replacement can be made. (3) Ferrying an airplane with any inoperative altitude alerting system or device from a place where repairs or replacements cannot be made to a place where it can be made. (4) Conducting an airworthiness flight test of the airplane. (5) Ferrying an airplane to a place outside the United States for the purpose of registering it in a foreign country. (6) Conducting a sales demonstration of the operation of the airplane. (7) Training foreign flight crews in the operation of the airplane before ferrying it to a place outside the United States for the purpose of registering it in a foreign country. [Docket 18334, 54 FR 34304, Aug. 18, 1989, as amended by Amdt. 91-296, 72 FR 31679, June 7, 2007]
Oral Exam Questions a DPE Might Ask
Q1What aircraft are required to have an altitude alerting system, and what does the regulation require it to do?
Per FAR 91.219, turbojet-powered U.S.-registered civil airplanes must have an approved, operable altitude alerting system that warns the pilot — by aural and/or visual signals — when approaching or deviating from a preselected altitude, working from sea level to the airplane's maximum approved altitude.
Q2If the altitude alerting system fails after takeoff, can you continue the flight?
Yes. FAR 91.219(d)(2) allows the flight to continue as originally planned if the system becomes inoperative after takeoff, but you may not depart again from a place where repair or replacement is possible.
Q3Does FAR 91.219 apply to a turbojet operating on an experimental certificate?
No. Under FAR 91.219(d), the altitude alerting system requirement does not apply to airplanes operating on an experimental certificate, along with several other listed operations like ferry, sales demos, and airworthiness flight tests.
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FAR 91.219 — Altitude Alerting System for Turbojets