Tue, Aug 08, 2017
FAA Expected To Formalize Compliance With Mandatory Service Bulletin SB 632A
The owners of thousands of aircraft equipped with Lycoming engines have been notified of Lycoming Mandatory Service Bulletin 632A titled “Identification of Connecting Rods with Non-Conforming Small End Bushings.”
According to Michael Busch, CEO of Savvy Aviation, the bulletin is intended to address a problem with small-end connecting rod bushings (part number LW-13923) that were used shipped by Lycoming to overhaul shops and mechanics between November 2015 and November 2016. There apparently was a quality control problem with the bushings, and some did not have the correct outside diameter to conform with engine specifications.
In a small number of cases, the bushings appear to be migrating out of the connecting rod while in service, which has led to the SB.
At the very least, the SB 632A will affect well over a thousand new and Lycoming-Factory-Rebuilt engines. What is not known is how many engines have been overhauled or repaired in the field during the time when the bushings were being used, and neither Lycoming or the FAA has been willing to say what that number is.
To comply with the SB 632A, any engine that may have the non-conforming bushing must have all cylinders removed within the next 10 hours of operation, and a special tool must be used to determine if the bushing fits properly. Lycoming estimates that there will be a 20 percent failure rate, meaning one in every five connecting rods will have to be replaced. Busch warns that there is a history of catastrophic engine failures after all cylinders have been removed in the field. They also say that the majority of A & P mechanics do not have the expertise to conduct the inspections.
Lycoming has more recently issued a revision of the Service Bulletin, but Busch still believes that the likely AD will be "painful" for may Lycoming owners.
(Image provided with Savvy Aviation newsletter)
More News
Aero Linx: JAARS Nearly 1.5 billion people, using more than 5,500 languages, do not have a full Bible in their first language. Many of these people live in the most remote parts of>[...]
'Airplane Bounced Twice On The Grass Runway, Resulting In The Nose Wheel Separating From The Airplane...' Analysis: The pilot reported, “upon touchdown, the plane jumped back>[...]
"Burt is best known to the public for his historic designs of SpaceShipOne, Voyager, and GlobalFlyer, but for EAA members and aviation aficionados, his unique concepts began more t>[...]
"Polaris Dawn, the first of the program’s three human spaceflight missions, is targeted to launch to orbit no earlier than summer 2024. During the five-day mission, the crew >[...]
There Are SO Many Ways To Get YOUR Aero-News! It’s been a while since we have reminded everyone about all the ways we offer your daily dose of aviation news on-the-go...so he>[...]