EASA SIB NE-08-26R3
Lycoming Engines - TCM Ignition Systems (formerly Bendix) D2000 and D3000 Dual Magnetos
Summary
The Lycoming Engines - TCM Ignition Systems (formerly Bendix) D2000 and D3000 Dual Magnetos Special Airworthiness Information Bulletin (SAIB: NE-08-26R3) is an FAA informational bulletin addressing the risk of magneto separation from Lycoming four, six, and eight cylinder reciprocating engines equipped with TCM Series D2000 and D3000 Dual Magnetos. This bulletin specifically highlights issues found mostly in Lycoming IO-360-A1B6D and IO-360-A3B6D engines installed on Mooney M20J-201 and Cessna 177RG aircraft. It provides guidance on inspection, maintenance, and proper gasket and clamp usage to prevent magneto separation and subsequent engine power loss.
What Changed
This revision updates the Lycoming Service Instruction number from 1508B to 1508C, maintaining all other information. It clarifies proper gasket installation, magneto clamp usage, and inspection procedures to prevent magneto separation. The bulletin also emphasizes the need for non-destructive testing of magneto housing mounting flanges during overhaul.
Why It Matters
Magneto separation during flight can cause engine power loss, posing a safety risk. Aviation professionals, including operators and maintenance organizations, must understand the correct maintenance practices to avoid magneto flange wear and failure. Proper inspection and torque procedures ensure continued airworthiness and prevent costly in-flight failures or unscheduled maintenance.
What To Do
Operators and maintenance personnel should inspect magneto housing mounting flanges for wear or cracks before installation and replace any defective magnetos. Only use the specified gasket (P/N LW-12681) and new style magneto clamps (P/N 66M19385). Replace lock washers (P/N STD-475) each time clamps are removed, and torque nuts (P/N STD-1410) per Lycoming SI No. 1508C. Regularly check magneto tightness at oil changes and inspections, and ensure magneto overhaul facilities perform fluorescent penetrant inspections for cracks.
AI-generated summary from official EASA source document. Always verify against the original.