Document ID: chunk:federal_register_of_legislation:F2014L00502:body:0:p2
Version: federal_register_of_legislation:F2014L00502
Segment Type: other
Provision Reference: 
Character Range: 2963–4258

taken as follows:

                     (a)     for Requirement 1: if not previously complied with, before further flight. Otherwise, at intervals not exceeding 3,000 FC from the last inspection.

                     (b)     for Requirement 2: before further flight.

                     (c)     for Requirement 3: after the effective date of this AD.
                This Airworthiness Directive becomes effective on 9 May 2014.
Background:     The requirements of this AD address the same unsafe condition as EASA AD 2009‑0036 with an effective date of 20 February 2009.

                A multiple fan blade failure event was reported on a CFM56-3 engine model.  Severe wear was observed on the underside of the fan blade platforms at the contact location with the fan blade dampers. This resulted in poor damping of the fan blade set and contributed to high dynamic stress of the blades.

                For the reasons stated above, this AD requires repetitive inspections of fan blades with 25 degrees mid-span shrouds as defined by CFM SB CFM56-3/3B/3C 72-1067 original issue in order to reduce the risk of a multiple fan blade failure event which could result in an uncontained engine rotor failure.

Mike Higgins
Delegate of the Civil Aviation Safety Authority

30 April 2014