EASA SIB 2011-24R1: European Geostationary Navigation Overlay Service (EGNOS) Availability

What to do

Pilots and operators should be prepared for possible sudden loss of SBAS/GNSS VNAV and LNAV functions during approaches and ensure that contingency procedures and alternate approach procedures are readily available and understood. Operators should monitor updates from ESSP and EASA and maintain communication with regulatory authorities for further guidance. No mandatory compliance deadline is specified, but vigilance and readiness are recommended.

Summary

EASA Safety Information Bulletin SIB No: 2011-24R1 titled European Geostationary Navigation Overlay Service (EGNOS) Availability addresses the operational status and performance of the EGNOS Safety of Life service for aircraft certified to conduct RNAV/GNSS approaches to LPV or LNAV/VNAV minima in European airspace. It informs that despite improvements, EGNOS does not fully meet ICAO Annex 10 requirements for continuity and availability during APV SBAS approaches. The bulletin applies broadly to all aircraft using SBAS-based navigation approaches in Europe.

What changed

This bulletin updates stakeholders on the deployment of a new EGNOS release that corrects previously identified incoherencies in geostationary satellite position and orbit data messages. The update improves EGNOS Signal-In-Space performance but acknowledges that full compliance with ICAO standards for continuity of service has not yet been achieved. It also reminds European airspace regulators to implement operational mitigations for SBAS approaches until full compliance is reached.

Why it matters

The bulletin highlights a potential increase in loss of integrity monitoring or navigation alerts during SBAS-based approaches, which could lead to sudden unavailability of VNAV and possibly LNAV functions. This impacts pilots and operators by increasing the risk of having to revert to alternate navigation methods or approaches, affecting flight safety and operational continuity. Awareness and preparation for these limitations are critical for compliance and safe flight operations.