2013-20-13
FR doc 2013-24037AD 2013-20-13Published 2013-11-05Effective 2013-12-10
Superseded by 2021-11-01
Supersedence is read from the Federal Register text of the newer AD — the FAA publishes no structured field for it — and names only ADs held in our index.
Requires installing a placard beneath the engine power dual tachometer and revising the operating limitations section of the rotorcraft flight manual (RFM).
Full official abstract
We are adopting a new airworthiness directive (AD) for certain Bell Model 206B and 206L helicopters. This AD requires installing a placard beneath the engine power dual tachometer and revising the operating limitations section of the rotorcraft flight manual (RFM). This AD was prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady-state operations. These actions are intended to alert pilots to avoid certain engine speeds during steady- state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter.