EASA SIB 2023-03R1
Incorrect Barometric Altimeter Setting
Summary
EASA Safety Information Bulletin 2023-03R1 is a revised bulletin addressing the risks associated with incorrect barometric altimeter settings during flight operations below the transition level. It applies to all aircraft operators and Air Navigation Service Providers (ANSPs) and highlights the safety concerns related to altitude errors that could lead to controlled flight into terrain (CFIT) or mid-air collisions. The bulletin emphasizes the importance of accurate barometric pressure settings for vertical navigation during various approach phases.
What Changed
This revision updates the original EASA SIB 2023-03 issued on 09 March 2023 by clarifying recommendations to ANSPs and aircraft operators following additional incident reports involving incorrect altimeter settings. It reinforces the need for improved communication and monitoring procedures but does not introduce mandatory safety directives or new regulatory requirements.
Why It Matters
Incorrect barometric altimeter settings can compromise vertical navigation safety margins, increasing the risk of terrain or obstacle clearance issues and loss of separation between aircraft. For aviation professionals, this bulletin underscores the critical need to verify and maintain accurate altimeter settings to prevent serious incidents and enhance flight safety during approach and landing phases.
What To Do
ANSPs should ensure QNH transmissions are correctly provided and acknowledged by arriving aircraft and consider additional QNH updates during approach clearance or tower contact. Aircraft operators are advised to develop and assess procedures for verifying QNH consistency, update TAWS databases, and explore flight data monitoring methods to detect incorrect altimeter settings. No specific compliance deadlines are stated as the recommendations are non-mandatory.