Propellers/Propulsion - Controlling

FAA Aircraft Certification Service SPECIAL AIRWORTHINESS INFORMATION BULLETIN SUBJ: Propellers/Propulsion - Controlling SAIB: CE-08-25 Date: May 23, 2008 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin is being issued to alert operators of the Dornier 228 series airplanes of daily checks of the negative torque sensing (NTS) system that are recommended by RUAG Aerospace Technology, which manages the continued airworthiness of these airplanes.

Background

The manufacturer of the engines used on the Dornier 228 series airplanes, Honeywell, has issued operating information letters (OIL) for daily cockpit checks of the NTS systems of the TPE331 series turbo shaft engines installed on the Dornier 228 series airplanes. The NTS system, if inoperative in the case of an engine failure, can cause severe airplane controllability problems. In certain circumstances and altitudes, the airplane may not be recoverable.

At this time, this airworthiness concern is not considered an unsafe condition that would warrant an airworthiness directive (AD) action under Title 14 of the Code of Federal Aviation Regulations (14 CFR part 39).

Recommendations

RUAG has issued Flight Operations Information FOI-228-009, which recommends that the daily NTS checks of Honeywell OIL OI331-20R1 and OI331-22 (depending on the type of NTS system installed) be done daily. The FAA recommends compliance with the provisions of the flight operations information; the provisions of which will be incorporated into the pilots operating handbook (POH).

For Further Information Contact

Karl Schletzbaum, Aerospace Engineer, Small Airplane Directorate, 901 Locust Street, Room 301, Kansas City, MO 64106; phone: (816) 329-4146; fax: (816) 329-4090; e-mail: [email protected].

For Related Service Information Contact

RUAG Aerospace Defence technology, P.O. Box 1253, D-82231 Wessling, Germany; phone: 011- 49-8153-302280; fax: 011-49-8153-302230.