United States carriers and private operators face costs estimated at €3.84 billion to upgrade radio altimeters to interference-tolerant units, according to Federal Aviation Administration figures released on 6 January 2026. The retrofit programme addresses potential interference from adjacent wireless spectrum bands. Compliance deadlines fall between 2029 and 2032 for commercial and large foreign-registered aircraft, with others granted two additional years.
The proposal covers aircraft under Parts 91, 121, 129 with thirty or more seats or payload over 3,401 kilogrammes, and Part 135. Approximately 40,871 aircraft require modification of at least 58,579 altimeters. Annualised costs project between €52 million and €128 million over twenty years, excluding downtime and supply-chain impacts.
