You may have heard by now that this past Monday, Lycoming issued Service Bulletin 632. (See link at bottom of this post.) SB632 covers all models of Lycoming engines. This SB requires an internal inspection within 10 flight hours of its date of issuance (July 17, 2017). This inspection requires the removal of all engine cylinders. Following removal of the cylinders and pistons, the small end of the connecting rods are inspected for bushing migration using a special tool that Lycoming calls out in the SB.

Please take this SB seriously. Lycoming has documented multiple cases of catastrophic engine failure caused by the migration of this bushing.

The scope of this SB is very large, affecting approximately 1500 engines. Many of these airplanes are listed specifically by serial number in the SB. Others are affected by the installation of suspect parts that were purchased from Lycoming during the time period specified in Table 2, on the last page of the SB. Unfortunately, Cub Crafters was hit particularly hard. In addition to several Top Cubs, every one of our XCubs was affected, with the exception of our second R&D plane.

Lycoming is working hard to get our customers back up and flying as quickly as possible. A field representative will be here at the factory tomorrow afternoon to begin accomplishing the SB on the multiple engines we have here in Yakima, both on airplanes and a few still crated in inventory. Additionally, Lycoming is fielding a team to Oshkosh to make sure nobody gets stranded at the show.

We are working our way through the list of known affected Cub Crafters aircraft, contacting customers directly to make them aware of the SB and to assist in any way we can. If you have a Lycoming engine, please review the attached SB to make sure you are not affected!

NOTE: THIS SB DOES NOT AFFECT THE CARBON CUB CC340 ENGINES OR THE SPORT CUB O-200 ENGINES! Those engines use different design bushings made by a different manufacturer.

Warranty: Please be aware that this is not a Cub Crafters warranty item; therefore, Cub Crafters terms and conditions do not apply. Please refer to your Lycoming Engine’s Limited Warranty for procedures, details, and limitations for filing a warranty claim related to this Service Bulletin. Warranty information is available online at http://www.lycoming.com/warranty. Contact an Authorized Lycoming Distributor for assistance with filing a warranty claim and to order all necessary parts.

Lycoming’s warranty procedures are very different from ours. You may use a mechanic of your preference, but the warranty MUST be approved and processed through a Lycoming distributor. There are no exceptions. Please make sure your mechanic understands this before beginning work.

SB632_Connecting_Rod_Identification_and_Removal_0 (2).pdf