TFE731 Engines: Recommendations for Operating in Volcanic Ash-Laden Environment

April 2010

Recent volcanic eruptions in Iceland have polluted the skies with large amounts of volcanic ash and have raised many questions about maintenance and inspection activity for aircraft engines.

Volcanic ash is particulate matter categorized as sandy grit to a powder like dust that can contain varying amounts of sulfur. It is highly abrasive and can cause corrosion to turbine components. The more concentrated the ash and the longer your engines are exposed, the more detrimental the effects.

Effects of particulate matter (volcanic ash)

The following engine conditions and changes are indications of particulate matter contamination.

• Engine surging
• Torching from the tailpipe and flameouts
• Unexpected engine temperature changes due to particulate concentrating in cooling holes and dropping efficiency.

You can estimate the rate at which the erosion is occurring by examining fan and compressor blades for abnormal erosion.

Recommendations

Whenever possible, avoid operation in known volcanic ash-laden environments. If operation cannot be avoided, the following is recommended:

• Examine engine oil filters more frequently to prevent oil blockage
• If operation is continual, engine oil change should be shortened to 150 hrs
• Examine fuel filters more frequently
• Use of inlet and exhaust covers when aircraft are stored outside

Refer to Honeywell SIL TFE731-37 for detailed instructions.

Operators who have engines covered by MSP or operators of engines that are still under new engine warranty need to be aware that repair expenses will be the responsibility of the operator. Honeywell considers this to be a FOD event (ingestion of foreign material) and coverage will be denied if defects are caused due to operation in volcanic ash.