Wooden Propellers Flashcards
Often found on older single engine A/C & Usually fixed pitch props. However there are some adjustable pitch
Wooden Propellers
Wooden propellers are fabricated from a minimum of _ layers of laminated kiln dried wood but can be up to __ layers thick
5-10
_____ stage lets the moisture distribute evenly through all of the propeller laminations.
prop white stage
Some propellers have a black or grey plastic coating to protect the wood known as ______ _______.
Armor Coating
___ ___ ___ ___ will be applied in layers to prevent moisture ingress which helps to prevent shrinking swelling and warping
clear water proof varnish
Why is there a paint in the tip of the propeller?
it will allow us to see the propeller tip when it is spinning
can be installed on the leading edge to protect against FOD
Erosion Shield
How is erosion shield secured?
countersunk screws rivets and solder
Why do we drill holes into the tips of the erosion shield?
This will allow moisture to escape via centrifugal force
an out of balance propeller will always stop at?
the same spot
When do we know if the prop is balanced?
If it stops at a random spot
Why are wooden prop stored horizontally?
for even moisture distribution which prevents the propeller from warping and keeps it balanced
Advantage of wooden props
Absorbs engine vibrations much better than metal
Does not support resonance
Lighter than metal props
Low initial purchase cost
Disadvantages of wooden props
more susceptible to abrasion and damage
difficult to fix
more maintenance
moisture swelling can change attach bolt torques
unequal moisture distribution can cause dynamic imbalance
glue condition, moisture content , warping, rotting, varnish, condition of wood laminations
