member of the tail rotor blade and is continuous from
Main Rotor Pylon
tip cap to tip cap. Two paddle assemblies, made up of
The main rotor pylon is attached to the upper cabin
honeycomb, are bonded to the spar. Several layers of
and transition section. The forward section is made up
fiberglass are bonded over the honeycomb and spar.
of a sliding control/accessories fairing, removable
These form the tail rotor blade skin and aerodynamic
platform, air inlet fairings, and engine air inlets. The
shape of the tail rotor blade. A deice heater mat is
mid-section includes the No. 1 and No. 2 work
bonded into the tail rotor blade leading edge. The heater
platform/engine access, left and right oil cooler access,
mat connects to an electrical connector mounted close
environmental control system (ECS) access, APU inlet,
to each counterweight. Power to heat the tail rotor
APU access, and exhaust module. The aft section
blades is supplied through a slipring on the tail gearbox
contains the fire bottle access and aft fairing.
from the deice system.
Tail Rotor Assembly
The H-60 tail rotor is a bearingless, controllable
The tail rotor pylon is a foldable section at the aft
pitch, cross-beam type system. The tail rotor blades are
end of the helicopter. The pylon is supported by and
built around two interchangeable graphite composite
hinged to the tail cone section. It supports the
spars that cross each other in the center. The two tail
horizontal stabilator, intermediate gearbox, tail
rotor blades are retained on the tail rotor hub by a set of
gearbox, connecting tail rotor drive shaft, tail rotor
retention plates. These plates bolt the tail rotor blades
assembly, and part of the flight controls. See figure
together to form four blades 90° apart. Counterweights
are bolted to each tail rotor blade for balancing. See
Q2-1. How many principal structural units are there
in a fixed-wing aircraft?
Q2-2. On a semimonocoque fuselage, what com-
Tail Rudder Blades
ponent absorbs the primary bending loads?
The tail rotor blades are built around two graphite
Q2-3. What aircraft structure is designed to trans-
composite spars. The spar is the main structural
mit engine loads, stresses, and vibrations to
the aircraft structure?
Q2-4. What is the main structural member of a wing
Figure 2-21.--H-60 tail pylon.
Figure 2-20.--H-60 tail rotor.