Radio Altimeter Rule Companion

This regulation does not affect aircraft that are currently not equipped with an RA system.

After December 30, 2030, unless otherwise authorized by the Administrator, no person may operate an aircraft under this part in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of Sec. 91.220(b) of this chapter.

FAA determined that an initial compliance date earlier than for other aircraft operations is necessary because they constitute flights by the major domestic and international airlines that affect the flying public, have the highest public expectation of safety, perform a significant majority of low-visibility operations that would otherwise be restricted to protect from hazardous interference, and are the most critical to the national economy.

FAA plans to ask part 121 and 129 operators to voluntarily submit equipage plans for their fleets to their respective certification management offices by the end of 2026 and to maintain those plans through the transition.

The FCC R&O also creates an RA retrofit rebate program for eligible U.S. civil aircraft owners and operators.

FAA plans to issue superseding ADs for transport and commuter category airplanes not otherwise shown to be compliant with the ITM to prohibit operators from conducting low-visibility approach and landing operations after December 30, 2030 until the aircraft becomes ITM-compliant.

(a) After December 30, 2030, unless otherwise authorized by the Administrator, no person may operate an aircraft with 30 or more passenger seats or a payload capacity of more than 7,500 pounds under this part in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of Sec. 91.220(b) of this chapter.

FAA determined that an initial compliance date earlier than for other aircraft operations is necessary because they constitute flights by the major domestic and international airlines that affect the flying public, have the highest public expectation of safety, perform a significant majority of low-visibility operations that would otherwise be restricted to protect from hazardous interference, and are the most critical to the national economy.

FAA plans to ask part 121 and 129 operators to voluntarily submit equipage plans for their fleets to their respective certification management offices by the end of 2026 and to maintain those plans through the transition.

In accordance with FCC's R&O, the RA retrofit rebate program is not available to foreign operators.

Part 129 operators may choose to segregate their international operation fleets, only replacing RAs in the aircraft they designate for operations in U.S. airspace; to the extent they do so would reduce the costs incurred by those operators pursuant to this final rule.

For aircraft operated by all other part 129 operators, who are not subject to FAA ADs because their aircraft are not U.S.-registered, any authorizations that allow operations with non-compliant RAs beyond the applicable RA compliance deadline will contain the same operating limitations that restrict low-visibility approach and landing operations as contained in the ADs.

(b) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft under this part in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of Sec. 91.220(b) of this chapter.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA plans to ask part 121 and 129 operators to voluntarily submit equipage plans for their fleets to their respective certification management offices by the end of 2026 and to maintain those plans through the transition.

In accordance with FCC's R&O, the RA retrofit rebate program is not available to foreign operators.

Part 129 operators may choose to segregate their international operation fleets, only replacing RAs in the aircraft they designate for operations in U.S. airspace; to the extent they do so would reduce the costs incurred by those operators pursuant to this final rule.

For aircraft operated by all other part 129 operators, who are not subject to FAA ADs because their aircraft are not U.S.-registered, any authorizations that allow operations with non-compliant RAs beyond the applicable RA compliance deadline will contain the same operating limitations that restrict low-visibility approach and landing operations as contained in the ADs.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

These final regulations require the installation of new or upgraded RA systems for all aircraft currently equipped with RA operating under part 121; the majority of aircraft operating under part 91, subpart K, as well as parts 125, 129, 135, and 194; aircraft with an RA installed operating under parts 133, 136, and 137; and a minority of general aviation (GA) aircraft operating under part 91.

Smaller non-commercial operators who are not required by regulation to have an RA, either directly or as an integral component of a mandated safety system, may remove the RA entirely and fly without one.

Regarding these RAs that are used only for situational awareness, FAA expects an overall safety improvement for aircraft that remove an RA that does not meet the new performance requirements due to the increased risk of interference, hazardously misleading altitude information, and pilots' subsequent loss of trust in the reliability of their RA data.

Entities that choose to replace the RA may also have access to noncommercial use units at lower cost than the estimated $80,000-$120,000, although FAA lacks data to estimate and did not receive public comment on what these units would cost.

Pilots or operators of aircraft with a special airworthiness certificate with an installed RA should evaluate the RA and determine if it is compliant with the ITM. If the RA meets the performance requirements of this final rule, no separate or specific FAA design approval is required.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA clarifies that the requirements in this final rule apply to all aircraft operations subject to part 91, as identified in the applicability provisions in Sec. 91.1. This includes aircraft operations that are also subject to parts 121, 125, 129, 133, 135, 136, 137, and 194.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA clarifies that the requirements in this final rule apply to all aircraft operations subject to part 91, as identified in the applicability provisions in Sec. 91.1. This includes aircraft operations that are also subject to parts 121, 125, 129, 133, 135, 136, 137, and 194.

Specifically, helicopters without an ITM-compliant RA system would be prohibited from performing takeoffs and landings in accordance with any procedure that requires the use of RA data (Category A, Category B, or by Performance Class in the Rotorcraft Flight Manual or Operations Specifications), engaging search and rescue autopilot modes, engaging hover autopilot modes, and performing certain procedures that require RA minima.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

Section 129.16(b) requirements align with the Sec. 91.220(b) compliance date of October 31, 2034, which is applicable to part 135 operators, among others, because of the similar economic impact and expected level of safety for those kinds of operations.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA clarifies that the requirements in this final rule apply to all aircraft operations subject to part 91, as identified in the applicability provisions in Sec. 91.1. This includes aircraft operations that are also subject to parts 121, 125, 129, 133, 135, 136, 137, and 194.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA clarifies that the requirements in this final rule apply to all aircraft operations subject to part 91, as identified in the applicability provisions in Sec. 91.1. This includes aircraft operations that are also subject to parts 121, 125, 129, 133, 135, 136, 137, and 194.

Specifically, helicopters without an ITM-compliant RA system would be prohibited from performing takeoffs and landings in accordance with any procedure that requires the use of RA data (Category A, Category B, or by Performance Class in the Rotorcraft Flight Manual or Operations Specifications), engaging search and rescue autopilot modes, engaging hover autopilot modes, and performing certain procedures that require RA minima.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA clarifies that the requirements in this final rule apply to all aircraft operations subject to part 91, as identified in the applicability provisions in Sec. 91.1. This includes aircraft operations that are also subject to parts 121, 125, 129, 133, 135, 136, 137, and 194.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

All other aircraft equipped with radio altimeters that are required to comply with part 91, including aircraft operating under parts 125, 133, 135, 136, 137, 194, and all other aircraft operating under part 129 that are not subject to the initial deadline, must comply with the same minimum performance requirements on or before October 31, 2034.

FAA clarifies that the requirements in this final rule apply to all aircraft operations subject to part 91, as identified in the applicability provisions in Sec. 91.1. This includes aircraft operations that are also subject to parts 121, 125, 129, 133, 135, 136, 137, and 194.

Therefore, the RA performance requirements in this final rule apply to all aircraft, both civil and public, operating in the airspace of the 48 contiguous United States and the District of Columbia.

(a) After October 31, 2034, unless otherwise authorized by the Administrator, no person may operate an aircraft in the airspace of the 48 contiguous United States and the District of Columbia with a radio altimeter unless the radio altimeter system meets the performance requirements of paragraph (b) of this section.

DOW preliminary estimates are included in the cost section as DOW is not eligible for rebate payments related to the spectrum auction.

This final rule does not address operations that are not subject to part 91, in accordance with the applicability provisions in Sec. 91.1, and therefore does not apply to UAS operating under part 107, operating under the proposed part 108

or conducting limited recreational operations under 49 U.S.C. 44809

The final rule also does not address operations under part 101 or 103, as ultralights, balloons, and other aircraft covered under these parts generally do not have RA systems.