EASA SIB NE-16-19: Honeywell Inc. TPE331 Turboprop Engines - Turbine Engine Compressor Section — Stator Nozzle Distress

What to do

Operators and maintenance facilities should perform borescope inspections of the 1st stage turbine nozzle vanes at every fuel nozzle inspection interval, not exceeding 450 hours since the last inspection. Inspections should be conducted through four fuel nozzle boss openings using an RF Systems videoscope with a 3.9 mm or 6.9 mm flex insertion tube or equivalent, employing a guide tube as specified. Any signs of unacceptable nozzle vane conditions should be addressed promptly according to maintenance guidelines.

Summary

The Special Airworthiness Information Bulletin SAIB: NE-16-19 is an FAA informational bulletin addressing turbine engine compressor section stator nozzle distress in Honeywell Inc. TPE331-10 and TPE331-11 series turboprop engines. It alerts operators and maintenance personnel to 1st stage turbine blade failures linked to nozzle vane burn-through and provides additional inspection guidance to prevent these failures. The bulletin supplements Honeywell Service Bulletin TPE331-73-0284 and does not mandate regulatory action.

What changed

This bulletin introduces enhanced recommendations for borescope inspections of the 1st stage turbine nozzle vanes during fuel nozzle inspections, recommending inspections at intervals not exceeding 450 hours. It also specifies the use of particular videoscope equipment and viewing techniques to improve detection of nozzle vane distress, supplementing existing Honeywell maintenance instructions.

Why it matters

This information is critical for aviation professionals to prevent in-flight shutdowns and turbine damage caused by premature 1st stage turbine blade failures. By following the recommended inspection procedures, operators and maintenance organizations can identify nozzle vane burn-through early, reducing the risk of severe engine damage and improving engine reliability and safety.