EASA SIB AIR-21-14
HeliSAS Autopilot Flight Control Computer / Garmin Primary Flight Display
Summary
The Special Airworthiness Information Bulletin AIR-21-14 is an FAA informational bulletin addressing the HeliSAS autopilot system and Garmin Primary Flight Display (PFD) interface on Robinson R44-series and R66 helicopters. It highlights a potential issue where the HeliSAS autopilot may fail to disengage vertical or lateral guidance when a VHF NAV or glideslope flag appears on the Garmin PFD. This bulletin applies specifically to Robinson R44 and R66 helicopters equipped with both the HeliSAS autopilot and Garmin PFD.
What Changed
This bulletin informs operators that some Robinson R44 and R66 helicopters were manufactured without the necessary resistors in the wiring harness that allow the autopilot to correctly interpret flag signals from the Garmin PFD. It introduces awareness of this issue and references Robinson Service Bulletins SB-106 for the R44 and SB-37 for the R66, which provide retrofit instructions to install the required resistors. The bulletin clarifies that the issue does not currently warrant an airworthiness directive.
Why It Matters
This information is important for aviation professionals because the autopilot may remain engaged without proper vertical or lateral guidance during instrument approaches, potentially affecting flight safety. Operators and maintenance teams need to be aware of this issue to ensure proper system functionality and avoid unexpected autopilot behavior. Compliance with the recommended service bulletins helps maintain safe autopilot operation and regulatory compliance.
What To Do
Owners and operators of Robinson R44 and R66 helicopters equipped with the HeliSAS autopilot and Garmin PFD should comply with Robinson Service Bulletin SB-106 for the R44 and SB-37 for the R66, both dated August 21, 2020, to retrofit the necessary resistors. There is no mandatory compliance deadline stated, but timely action is recommended to ensure proper autopilot function. For further information, contact the FAA aerospace engineer or Robinson Helicopter Company as provided.