EASA SIB SW-11-31R1
Honeywell MK XXII Enhanced Ground Proximity Warning System (EGPWS) - Software Update
Summary
The Special Airworthiness Information Bulletin SAIB: SW-11-31R1 is an FAA informational bulletin regarding the Honeywell MK XXII Enhanced Ground Proximity Warning System (EGPWS) installed on rotorcraft. It addresses a software update needed to correct an issue where the system may fail to announce loss of certain functions, potentially reducing the effectiveness of predictive terrain warnings. This bulletin applies specifically to rotorcraft equipped with the Honeywell MK XXII EGPWS system.
What Changed
This revised SAIB provides updated information on how to apply the recommended software update to the Honeywell MK XXII EGPWS system. The update corrects a condition where the system may not transition properly from on-ground to in-flight mode, which disables the predictive 'look-ahead' warnings without alerting the pilot. The software update is available from Honeywell at no charge and is detailed in Honeywell Service Bulletins ATA Numbers 965-1590/1595-34-36 and 965-1595-34-22.
Why It Matters
For aviation professionals, this update is important because failure to install the corrected software could lead to reduced situational awareness and less effective terrain avoidance warnings. Operators and maintenance organizations must ensure the EGPWS functions as intended to maintain safety margins against controlled flight into terrain or obstacles. Compliance helps avoid degraded system performance that is not currently subject to mandatory airworthiness directives but poses operational risks.
What To Do
Owners and operators of rotorcraft with the Honeywell MK XXII EGPWS should contact Honeywell and the Supplemental Type Certificate holder to arrange installation of the updated application software as described in the referenced Honeywell Service Bulletins. The update is provided at no cost. There is no mandatory compliance deadline stated, but timely installation is strongly recommended to maintain system effectiveness.
AI-generated summary from official EASA source document. Always verify against the original.