Propeller Owner’s Manual
147
INTRODUCTION
61-00-47
Page 1-27
Rev. 16 May/20
Term
Definition
Trailing Edge
The aft edge of an airfoil over which the air
passes last
Trimline
Factory terminology referring to where the
part was trimmed to length
Underspeed
The condition in which the actual engine
(propeller) RPM is lower than the RPM
selected by the pilot through the propeller
control/condition lever
Unidirectional
Material
A composite material in which the fibers are
substantially oriented in the same direction
Variable Force
A force that may be applied or removed
during propeller operation
Vertical Balance
Balance between the leading and trailing
edges of a two-blade propeller with the
blades positioned vertically
Voids
Air or gas that has been trapped and cured
into a laminate
Windmilling
The rotation of an aircraft propeller caused
by air flowing through it while the engine is
not producing power
Woven Fabric
A material constructed by interlacing fiber to
form a fabric pattern
Wrinkle (aluminum
blade)
A wavy appearance caused by high and low
material displacement
Wrinkle (composite
blade)
Overlap or fold within the material
