Powerplant - Salt Encrustation

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FAA Aviation Safety SPECIAL AIRWORTHINESS INFORMATION BULLETIN SUBJ: Powerplant - Salt Encrustation SAIB: NE-14-14 Date: April 14, 2014 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin alerts you, owners, operators, and certificated repair facilities of the possibility of salt encrustation and engine performance degradation while operating the Sikorsky Aircraft Corp. S-92A in a heavy salt spray environment. At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

The Sikorsky S-92A is capable of over water search and rescue (SAR) operations. These operations may include flying at low speeds and low altitudes in a heavy salt spray environment. Some Sikorsky military products, such as the H-60 that is powered by a military variant of the S-92A engine, include information in the flight manual that cautions that salt encrustation and subsequent engine performance degradation can occur when operating in a high salt spray environment. This information is not included in the S-92A flight manual supplement related to SAR. A general revision of the flight manual, which is tentatively planned for the 4th quarter of calendar year 2014, will include this information.

Recommendations

For operations that take place in a heavy salt spray environment, the pilot should monitor turbine gas temperature (TGT) relative to engine torque. Any abrupt rise in TGT might indicate salt encrustation and possible engine power degradation or imminent compressor stall. If a rise in TGT is observed while maintaining constant engine torque, the pilot should give priority to exiting the heavy salt spray environment. Flight through precipitation may help to reduce salt encrustation on engine components.

For Further Information Contact

John Coffey, Flight Test Engineer, Boston Aircraft Certification Office, FAA, 12 New England Executive Park, Burlington MA, 01803; phone: (781) 238-7173; fax: (781) 238-7170; email: [email protected].