FAA Recommends Upgrade for Collins SBAS Receiver Issue

The FAA is recommending that operators upgrade certain Collins Aerospace GNSS receivers that are not meeting minimum operational performance standards for processing an integrity message from Europe’s satellite-based augmentation system (SBAS), the agency noted in a Special Airworthiness Information Bulletin (SAIB). Currently, the condition does not warrant an airworthiness directive, the FAA said. EASA issued a mandatory directive last year, AD 2025-0088, requiring replacement of affected receivers for aircraft registered in member states.

According to the FAA, the issue stems from a November 2023 ground system update to the European Geostationary Navigation Overlay Service (EGNOS), which exposed noncompliance in affected Collins GPS-4000S, GLU-2100, GLUS-2100, and GLUS-2100A receivers. This noncompliance results in incorrect processing of the Message Type 6 integrity alert, which the FAA said may affect the availability of Localizer Performance with Vertical guidance and other SBAS-based approach types. The issue is most prevalent within EGNOS coverage but may affect other SBAS regions.

The FAA recommends that operators with affected hardware and software configurations upgrade to serviceable receivers per Collins Aerospace service documentation.

Collins GPS-4000S and GLU-2100 receivers were previously the subject of a separate, unrelated service disruption in 2019 that affected GPS navigation and ADS-B transponder functionality in the U.S., prompting the FAA to issue temporary operational exemptions. That earlier issue was resolved through a GPS constellation update.