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
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
Benefits of a dynamically balanced propeller:
- Increased ride comfort
- Reduces instrument/avionic/engine wear
- Increased component service life
- Increased safety
- Reduced vibration induced fatigue
- "Normal" vibration will be gone
For further information please call Monarch Aviation,