Recommendations for Rotorcraft During Icing Conditions SAIB SW-08-03

As a continued emphasis item regarding loss of engine power resulting from snow or ice ingestion on turboshaft powered rotorcraft, we are revising and reissuing this Special Airworthiness Information Bulletin (SAIB) and are urging you to follow our recommendations.
This SAIB alerts you, owners and operators of turboshaft powered rotorcraft, of the possibility of inflight engine loss of power, due to the ingestion of ice and snow. Accumulation of ice and snow can occur in the area of the airframe engine inlet while the rotorcraft is on the ground or in the air. This SAIB describes procedures to reduce the probability of an engine in-flight shutdown due to ice and snow ingestion.

Background
We have determined that ingested ice and snow accumulation in the airframe engine inlet can cause the engine to lose power. This has resulted in accidents and fatalities. Snow and ice can build up in the engine intakes and plenums when the rotorcraft is on the ground with the engine(s) not operating or are operating at a low power setting for extended periods. When a pilot increases engine power during takeoff, the accumulated snow and ice can separate from the airframe inlet surface and be ingested into the engine, resulting in decreased power or complete engine failure. Some of the early
turboshaft engines with axial inlets are particularly susceptible to loss of power due to ice and snow ingestion.

SAIB Attached