Figure 2-17.--H-60 main rotor blades.
Main Rotor Assembly
components of the main rotor head are as follows: hub,
The main rotor (rotary wing) and the rotor head are
droops stops, bifilar absorber, pitch control rods,
discussed in the following section. Their functions are
dampers, damper accumulator, anti-flap assemblies,
closely related and neither has a function without the
swashplate, swashplate guide shaft extension, pressure
plates, and rotor blade fold system. See figure 2-19.
The H-60 has four main rotor blades that provide
lift for the helicopter. See figure 2-17. They receive
power from the main rotor head to which they are
attached. The root (inboard end of the main rotor blade)
allows bolting the main rotor blade to the main rotor
head. A heater mat in the main rotor blade leading edge
provides blade deicing, and it is connected to the blade
Each main rotor blade has a pressurized titanium
spar that is pressurized with nitrogen to detect cracks,
titanium abrasion strips. A removable sweptback tip
cap is attached by screws onto the end of each main
rotor blade. Pressure loss in the spar is indicated
through the use of a blade inspection method (BIM®)
indicator. This indicator is located at each main rotor
blade root, and continuously monitors spar pressure.
See figure 2-18.
The H-60 main rotor head transmits the movement
Figure 2-19.--H-60 main rotor head.
of the flight controls to the four main rotor blades. The