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Bill Walker is Engine Technical Representative at Duncan Aviation. He has worked on corporate aircraft since 1996 and joined the Duncan Aviation team in 2004. Bill began his aviation career in the US Air Force in 1979 and did the Field detachment training on the CF34 (TF34 in the Air Force) in the early 1980s before his eventual transition into civilian aviation.
How to Understand & Manage Jet Engine Vibration Are you looking for practical tips and expertise on managing the vibration levels of your business jet’s engines? Duncan
Aviation’s Bill Walker shares insights on the common causes
and preventative maintenance operators should undertake… ll aircraft engines experience vibration. That is normal and acceptable. However, because of the tight manufacturing tolerances of today, it’s important to balance the rotating engine groups as low as possible for reasons that include:
A • • •
Avoiding early wear and deterioration of parts; Avoiding damage to the aircraft; and Optimizing passenger comfort.
What Causes Jet Engine Vibration Issues?
The causes for engine vibration issues vary. Most of today’s turbofan engines have two rotating groups: • •
The fan (Low Pressure) and The core (High Pressure).
The fan section spins much slower than the core but is larger in diameter and is usually the culprit for engine vibration. www.AVBUYER.com
Common Core Vibration Causes: Once balanced by a designated overhaul facility, the core won’t usually cause vibration problems. When vibration is experienced it tends to be that there is foreign object damage (FOD) or an oil-related issue. Common Fan Vibration Causes: Fan vibration issues are more varied, and could be caused by dirt and contaminants from the atmosphere or lack of lubricant (dry lube) on the fan blade tang or fan disk bushing migration (depending on engine type), preventing the fan blades from moving freely. Typically, fan blades that are loosely installed find their proper load position with an engine at RPM. Fan blades that are tight or locked in place may not find their load position and could prevent others from doing so, causing an unbalance which results in increased vibration.
How to Stay on Top of Jet Engine Vibration
It’s relatively easy to monitor your engine’s vibration levels. Operators who perform Engine
AVBUYER MAGAZINE Vol 24 Issue 2 2020
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