FAA AD 2017-16-11 on Lycoming Engines

This AD 2017-16-11  requires an inspection of connecting rods and replacement of affected connecting rod small end bushings.  AD was prompted by several reports of connecting rod failures resulting in uncontained engine failure and in-flight shutdowns (IFSDs).  AD applies to:           (1) All Lycoming Engines reciprocating engines listed in Table 1 of Lycoming Engines MSB No. 632B, dated August 4, 2017, and

(2) all Lycoming Engines reciprocating engines that were overhauled or repaired using any replacement part listed in Table 2 of Lycoming MSB No. 632B, which was shipped from Lycoming Engines during the dates listed in Table 2 of Lycoming  MSB No. 632B.

Reason of this AD is reports of uncontained engine failures and IFSDs due to failed connecting rods on various models of Lycoming Engines reciprocating engines listed in Table 1 of Lycoming MSB No. 632B, that were overhauled or repaired using any replacement part listed in Table 2 of Lycoming Engines MSB No. 632B, which was shipped from Lycoming Engines during the dates listed in Table 2 of Lycoming Engines MSB No. 632B.

This AD requires accomplishing the instructions in MSB  describing procedures for inspecting connecting rods and replacing connecting rod small end bushings to prevent connecting rod failure.  If not complied, could result in uncontained engine failure, total engine power loss, IFSD, and possible loss of the airplane.

Lycoming has determined that a small percentage of the bushings manufactured by a sub-supplier during a specific time period were diametrically undersized, resulting in a tightness of fit below factory accepted tolerances.These non-conforming bushings may have a substantially lower push-in/pull-out force than conforming bushings and may be susceptible to unseating during normal engine operations.

 Required Actions

(1) For all affected engines, within 10 operating hours after the effective date of this AD, inspect all affected connecting rods as specified in MSB.

(2) Replace all connecting rods that fail the inspection required by  this AD with parts eligible for installation.

Author: spsingh

Aircraft Engineer, 39 years aviation experience. Working as Quality Manager. Reading & Writing is my hobby.

Leave a Reply

Your email address will not be published. Required fields are marked *