AD 2014-23582

Abstract

We are revising and reopening the comment period for an earlier notice of proposed rulemaking (NPRM) for certain Bell Helicopter Textron Canada Limited (Bell) Model 206L-3 and 206L-4 helicopters. The NPRM proposes to require installing a placard and revising the limitations section of the rotorcraft flight manual (RFM). The NPRM was prompted by several incidents of third stage engine turbine wheel failures caused by excessive vibrations at certain engine speeds during steady-state operations. This action proposes to revise the NPRM by adding certain Model 206L1 helicopters to the applicability, excluding certain Model 206L3 and 206L4 helicopters from the applicability, and changing the procedures for updating the RFM. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.

Applicability · by US fleet size

• BELL 206L-3 TCDS H2SW 163 tails
• BELL HELICOPTER TEXTRON 206L-1 TCDS H2SW 147 tails
• BELL HELICOPTER TEXTRON CANADA 206L-4 TCDS H2SW 103 tails
• BELL 206 TCDS H2SW 18 tails
• BELL 230 TCDS H9SW 13 tails
• BELL 206L TCDS H2SW 6 tails
• BELL HELICOPTER TEXTRON CANADA 206L-3 TCDS H2SW 4 tails
• BELL 47B TCDS H-1 1 tails

Compliance instructions

Required actions, compliance times, parts/serial numbers and methods of compliance are in the Federal Register publication — not paraphrased here. Read AD on Federal Register ↗