While there are any number of components that are necessary to make an aircraft fly, it’s safe to say that the engine may be the most important. The engine’s fan is a powerful, highly critical part and its mass plus constant high-speed rotation make it especially vulnerable to falling out of balance. When the fan is unbalanced, it can create a large amount of noise and vibration that resonates in the cabin. If the imbalance is allowed to continue, it can damage the blades, engine, and critical aircraft components.
How Fans and Turbines Become Unbalanced
Fresh from the original manufacturer’s line, a fan or turbine assembly is engineered to operate at its ideal level. The blade placement is optimized for greatest performance, but if damage occurs to one or more blades, it can create an out-of-balance condition. Other conditions, such as blade erosion, past FOD damage and repairs, and even normal wear can contribute to fan imbalance. Another situation that can affect the fan’s balance is the replacement of damaged and worn fan blades. In most cases, the blades are changed in pairs, where the damaged or worn blade is replaced along with the blade that is symmetrically opposite. On the surface, it may appear that installing a matched pair of blades will not be a problem, but it can change the overall vibration signature of the fan.
Fan and Turbine Balancing
To gauge whether a fan or turbine has become unbalanced and to what degree, a Vibration Spectrum Survey must be performed. If the results of the test are given, technicians can then proceed to inspect the fan assembly, make repairs or replacements, and perform a Fan Trim Balance to bring the vibration levels down to an acceptable level. Rapid testing with accurate readings is critical in a fast-paced maintenance facility. ACES analyzers provide top of the line engineering and processing to help technicians work smarter and faster, and keep their aircraft in perfect operating condition.
The ACES Edge
Transient Balancing, which provides automated monitoring of all engine speeds during balance runs, is just one of several options available with our Viper II Vibration and Performance Analyzer. Our Fan Blade Mapper program helps to optimize fan blade layout, simplifying the process of replacement and balancing. ACES tools deliver vital data in the minimum number of passes, which saves time and money. 1GB of memory and USB port connectivity in the Viper II allow easy access to information that can be recalled later. Customizable input for different aircraft engines and airframes make targeted, model-specific testing more convenient.