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We are FAA Certified under Course No. AGL/0108/0004/6
Did
you know that 90% of all the aircraft out there have never had their
propellers Dynamically Balanced with the aft is not in balance with the
centrifugal forces of the engine it causes a lot of stress on the
crankshaft, internal engine components (pistons included) and travels
all the way through the airframe. It also causes Cabin noise and
vibrations that most aircraft owners do not realize are there because
they have become accustomed to them and assume that the vibrations and
cabin noise are normal. Do yourself, your passengers and your aircraft a
favor and have your propeller Dynamically Balanced. You will be
surprised how much more comfortable a long flight will be with a
smoother running aircraft. You may even see better fuel consumption,
better rates of climb and a slightly higher cruise speed. All that
energy that is wasted by the propeller not being in balance with the
engine can now be harnessed to gain thrust and a smoother,
more efficient and quieter running aircraft. The cost is only
$275 for single reciprocating engine aircraft, $425 for single Turb-Prop
and in most cases can be done while you wait. Discounts on twins and multiple aircraft. We can also check the balance of your propeller without balancing it, the cost for this is $175.00
Our equioment, the Microvib II, made by Dynamic Solutions, also
has the capability to comply with the More STC for Pratt & Whitney
PT-6 Turbo prop engines. Blue Skies Aviation has the extra equipment and
software to place the PT-6 on the More STC and to print the required
reports for the More STC. Give us a call or send us an e-mail regarding
this service.
What is dynamic propeller balancing?
Dynamic Propeller Balancing is the
process whereby an electronic balancer is used to measure the
vibration produced by the aircraft power plant. Small trim balance
weights are added to the propeller/crankshaft assembly to correct for
errors in mass distribution and to reduce power plant vibration due to
mass imbalance to the lowest level practical.
How is it done?
The engine/propeller combination
is balanced right on the aircraft, in a flight ready state. A small
vibration sensor (accelerometer) is attached to the engine in a location
where vibration due to mass imbalance is maximum. A small tach
pickup (photo-tach) is also mounted to the cowl or engine to produce a
propeller tach signal. The engine is operated and the vibration and
tach signals are processed by the electronic balancer.
The balancer produces a vibration level (magnitude) which corresponds to the amount of mass imbalance which exists. The balancer also provides a "phase angle" which corresponds to the location
of the mass imbalance on the propeller disk. The vibration level and
phase angle are used to compute a balance solution (weight amount and
location). The balance solution is added to the propeller and the
measurement is repeated until the vibration level is found to be
acceptable.
My aircraft runs fine. Why should I have my prop dynamically balanced?
By all
means, have your propeller balance checked. The average airplane which
has not had a Dynamic Prop Balance has a vibration level due to
propeller/crankshaft mass imbalance of about .450 inches per second
(IN/S) velocity. This level is more than four times higher than what is
considered to be an acceptable vibration level for propellers and
represents a significantly higher level of wear and fatigue on engine
components and accessories (especially the crankshaft, cylinders and yes...even your airframe).
This average level is usually very noticeable to the pilot and
occupants. Yours may be higher or lower than the average but only a
mechanic with a vibration analyzer can tell for sure. On the average, 19
out of 20 fixed-wing aircraft can benefit from Dynamic Prop
Balancing yet many will never have it done.
My engine and prop were overhauled recently. Should I have my prop dynamically balanced?
Both new
and used components need to be dynamically balanced. In fact, the best
time to dynamically balance a propeller/engine combination is right
after overhaul when components are fresh. No appreciable difference was
found between the vibration levels of recently overhauled and longer
time propeller/engine combinations. Even brand-new aircraft with zero
time engines and propellers need to be dynamically balanced.
What level of propeller vibration is acceptable?
In most cases, the vibration level
due to mass imbalance can be brought down to under .100 IN/S very
easily. The average level seen post-propeller balance was .039 IN/S.
When propeller vibration levels are this low, the operator will
generally see a significant reduction in component wear and fatigue and
will find that the aircraft "feels" like a completely different machine.
In addition
to that the mechanic now knows what all of the other engine vibration
levels are (Prop/crankshaft mass imbalance usually dominates them) and
can utilize that information if additional work is needed.
But won't having my propeller dynamically balanced "mask" other engine problems?
No! An
engine with an internal problem which results in unusual vibration will
not respond to balancing in the same way that an engine which only
suffers from mass imbalance will. A qualified mechanic will use ALL of
the information available to make a judgment about your engine,
including the vibration response.
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