EASA SIB 2008-48
FAA SAIB CE-08-25 - Honeywell TPE331 Engines installed on RUAG Aerospace (Dornier) 228 Aircraft - Negative Torque Sensing (NTS) System Daily Checks
Summary
FAA SAIB CE-08-25 is a Special Airworthiness Information Bulletin addressing the Honeywell TPE331 engines installed on RUAG Aerospace (formerly Dornier Luftfahrt GmbH) 228 series aircraft. It focuses on the recommended daily checks of the Negative Torque Sensing (NTS) system to ensure proper engine operation and aircraft controllability. The bulletin highlights the importance of these checks for Dornier 228 models 228-100, 228-101, 228-200, 228-201, 228-202, and 228-212 equipped with TPE331 engines.
What Changed
This bulletin introduces recommendations for daily cockpit checks of the NTS system on Honeywell TPE331 engines installed on Dornier 228 aircraft. It does not mandate regulatory action but supports RUAG Aerospace's Flight Operations Information and Honeywell's Operating Information Letters for daily NTS system verification. The FAA and EASA both endorse these recommendations to enhance operational safety.
Why It Matters
The NTS system is critical for maintaining airplane controllability in the event of an engine failure. If the NTS system is inoperative, it can lead to severe control issues that may be unrecoverable at certain altitudes. Operators, maintenance personnel, and compliance teams must be aware of these checks to prevent potential safety risks and ensure continued airworthiness of affected aircraft.
What To Do
Operators of Dornier 228 series aircraft with Honeywell TPE331 engines should perform daily NTS system checks as recommended by RUAG Aerospace Flight Operations Information FOI-228-009 and Honeywell Operating Information Letters OI331-20R1 and OI331-22. These checks should be incorporated into daily pre-flight procedures and the pilots operating handbook. No mandatory compliance deadline is specified, but adherence is strongly advised.
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