Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Bell Textron Canada Limited (Bell) Model 206L, 206L-1, 206L-3, and 206L-4 helicopters with FAA Supplemental Type Certificate (STC) SR02684LA installed. This proposed AD was prompted by an event where a Bell Model 206L helicopter with FAA STC SR02684LA installed experienced moderate to severe vertical vibration, which resulted in damage to the tail boom of the helicopter. This proposed AD would require revising the Limitations section of the existing rotorcraft flight manual (RFM) for the helicopter to include a never-exceed-speed (V<INF>NE</INF>) limitation and would require incorporating a rotorcraft flight manual supplement (RFMS) into the existing RFM. The FAA is proposing this AD to address the unsafe condition on these products.