Dynamic Prop Balancing
     There are two types of prop balancing, static and dynamic. Static balancing is carried out by the prop overhaul shops; where props blades are literally filed until both ends weigh the same. Lycoming recommends that props should be overhauled (which includes static balancing) at major engine overhaul or every 2000 hours.

     Dynamic prop balancing is carried out with the prop fitted to the aircraft, and includes the entire rotating assembly (prop, crankshaft, spinner, spinner back plate, and ring gear). Dynamic balancing should be carried out any time that the engine or the prop is overhauled.

     After extensive factory training, Monarch Aviation Inc. has been certified by the FAA to carry out dynamic prop balancing.

     With rapid 'ACES' field support and technical propeller support from Air Prop Specialist, Inc. at Marianna, even the most problematic prop can be diagnosed, repaired, and dynamically balanced with minimal aircraft down time.

How is a dynamic balance carried out?

     Nothing is removed from the propeller or engine. A small vibration sensor (accelerometer) is mounted on the forward end of the engine (as close to the forward engine bearing as possible). A 'light source' or photo tach acquires the speed and phase angle data (the engine is then run). The resulting information is then processed by the probalancer analyzer 2020, which displays a resolution/correction (where and what weight is to be added). After the installation, a final engine run is carried out, and the probalancer analyzer prints out a final resolution/correction statement (which is placed in the log book). In normal use, propeller dynamic balance should be checked every 400 to 600 hours or after prop or engine overhaul.

Problems caused by out of balance propellers:

• Pilot fatigue
• Leaky oil coolers
• Cracked or broken exhaust manifolds
• Broken or cracked engine and/or turbo charger mounts
• Vacuum pump failure
• Avionic, alternator, fuel control failure