EASA SIB 2022-05
[Correction] Rotorcraft Flight Manual Update related to Servo Control Transparency
Summary
EASA Safety Information Bulletin 2022-05 is a correction notice addressing rotorcraft flight manual updates related to servo control transparency for Airbus Helicopters AS 350 (all models except B3 with dual hydraulic system), AS 355 E, and EC 120 B helicopters. It highlights the phenomenon of servo control transparency, which can cause unexpected flight control loads and flight path deviations, particularly affecting helicopters with single hydraulic systems and specific engine models like the ARRIEL 2B. The bulletin references previous service letters and airworthiness bulletins from Airbus Helicopters, FAA, and CASA Australia.
What Changed
This correction clarifies the reference to the Rotorcraft Flight Manual amendment Normal Revision 12, date code (21-07), specifying it applies to AS 350 B3 helicopters equipped with the ARRIEL 2B engine, not the ARRIEL 2B1 engine. It also reiterates the recommendation to incorporate this and similar RFM amendments for other affected helicopter models to address servo control transparency risks.
Why It Matters
Understanding and addressing servo control transparency is critical for flight safety as it can lead to sudden control difficulties and rapid altitude loss, especially during right-hand turns near the ground. Operators and pilots must be aware of the conditions that increase the risk, such as high airspeed and high collective pitch, to manage flight safely. Compliance with updated flight manual guidance helps mitigate these risks and supports safe helicopter operation.
What To Do
Owners and operators of affected Airbus Helicopters AS 350, AS 355 E, and EC 120 B models should update their Rotorcraft Flight Manuals by incorporating the recommended amendments related to servo control transparency. Flight crews must be informed about the phenomenon and operate the helicopters accordingly. There are no mandatory compliance deadlines as this bulletin provides information and recommendations only.