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EX-EASA(SIB)-251022-01 - Incorrect Barometric Altimeter Setting

Issue Date

Nov 3, 2025

Instructors Notified?

YES

Tags

ALL

Files & media

EASA_SIB_2023-03R1_1.pdf

ATO Notes

Summary of EASA SIB 2023-03R1 (22 October 2025)

Subject: Incorrect Barometric Altimeter Setting
Scope: Aircraft Operators and Air Navigation Service Providers (ANSPs)

Background:
Several serious incidents revealed that incorrect barometric altimeter settings during operations below the transition level can lead to insufficient terrain or obstacle clearance and loss of separation with other aircraft, potentially resulting in Controlled Flight Into Terrain (CFIT) or mid-air collisions.
The issue affects approach procedures relying on barometric vertical navigation (e.g. RNP APCH to LNAV/VNAV minima, RNP AR APCH, CDFA techniques). Incorrect settings may go undetected, as standard cross-checks in SOPs do not reveal the error.

Revision Note:
This bulletin revises the original SIB 2023-03 (09 March 2023) following additional reported incidents. The concern does not warrant a Safety Directive.

Key Recommendations:
For Aircraft Operators:
• Include procedures for verifying QNH/QFE consistency with ATIS or other sources.
• Evaluate and improve existing procedures; consider pre-selecting altimeters during approach briefings.
• Keep TAWS software and databases up to date.
• Explore methods within Flight Data Monitoring (FDM) to detect incorrect settings.

Additional Notes:
• Reinforces use of standard ICAO phraseology (Reg. (EU) 923/2012).
• Reminds operators and ANSPs to comply with occurrence reporting obligations (Reg. (EU) 376/2014).

Conclusion:
EASA emphasizes vigilance and improved procedural and technical defences to prevent incorrect barometric altimeter settings, which remain a significant operational risk during approach and landing.

Valid

YES

🎓 Changes in this Revision

Although vertical guidance provided in the Final Approach Segment by ILS, SBAS or GBAS is not directly affected by incorrect barometric settings, barometric setting remains relevant for other phases of the approach (e.g. initial, intermediate and missed approach segments, and the goaround decision).

Since the publication of the original issue of this SIB, additional incidents have been reported in which incorrect altimeter setting has been identified as a contributory or causal factor. Consequently, this SIB is revised to further clarify the recommendations to ANSPs and aircraft
operators.

Assess the effectiveness of those already implemented procedures, and assess new procedures, e.g. pre-select altimeters based on latest information (e.g. ATIS), during the approach briefing. When this is not feasible, consider alternative systems to obtain/record QNH information
during the approach briefing phase.