MD Helicopters CSP-900RMM-2, Servicing And Maintenance

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CSP − 900RMM − 2 MD Helicopters, Inc.
Rotorcraft Maintenance Manual
Page 3
Revision 27
53-40-00
A. Tailboom Assembly
(Ref. Figure 2)
The tailboom assembly is an essential compo­
nent of the NOTAR
anti-torque system and
incorporates, on the right side of the assembly,
two air circulation control slots and 20 vortex
generators on helicopters equipped with the
thruster extension. The air circulation control
slots, that run nearly the entire length of the
tailboom, allow anti-torque fan air to exit the
surface of the tailboom assembly. The exiting
air, in conjunction with the downwash from
the main rotor, produces an airfoil effect over
the tailboom called the ``Coanda effect.” The
sideward force produced by the airfoil effect
combines with the force produced by the
thruster to exert the required main rotor
anti-torque force.
The tailboom assembly incorporates the
provisions for the attachment of the empen­
nage, the thruster extension or thruster,
thruster controls (Ref. Section 67-20-00), and
electrical harnesses to the aft end of the
aircraft (Ref. CSP-900WIR-8 Section
98-30-00).
The tailboom assembly is a multiple compo­
nent assembly. External components are the
tailboom, slat assembly, fuselage attachment
frame, and empennage forward and aft
attachment frames and intercostals. Internal
components are the upper and lower airfoils,
slot vanes, upper and lower inlet ramps, slat
spacers, diverter plate and attach flanges,
control cable tube and straps, forward and aft
coaxial covers, wiring cover, and electrical
conduits.
B. Tailboom
The tailboom detail assembly is a composite
sandwich panel that is cylindrical in shape and
is 22.51 inches (57.18 cm) in diameter and
124.18 inches (315.42 cm) in length. The
assembly is a partial cylinder and contains an
open area along most of the right side. The
sandwich panel is 0.250 inches (6.35 mm)
thick and fabricated of multiple plies of
graphite/epoxy cocured with a Nomex honey­
comb core.
At the forward end and the open area on the
right side of the assembly, the core is tapered
and the panel transitions to form monolithic
laminate flanges. At the aft end of the
assembly, in the area at and aft of the attach­
ment of the empennage forward attachment
frame, the panel transitions into a combina­
tion of a monolithic laminate and cored panel
incorporating a core of syntactic foam. Along
the lower surface the panel incorporates a
cocured exterior surface skin of aluminum foil.
The slat outer skin panel incorporates a cored
center section and monolithic laminate
peripheral flanges. The panel is fabricated
using multiple plies of graphite/epoxy cocured
with a Nomex honeycomb core.
The slat airfoil consists of a slat airfoil skin
and integral doublers and ribs. All components
are monolithic laminates and are fabricated
are using multiple plies graphite/epoxy.
The tailboom conduit is fabricated as a
monolithic laminate tube using multiple plies
of graphite/epoxy.
C. Thruster Extension
The thruster extension is installed between
the tailboom and the thruster. The thruster
extension moves the thruster 21 inches aft to
aid in anti-torque control.
The thruster extension is made of a composite
barrel with aluminum attachment frames at
each end. Around the barrel is a two-piece
composite fairing support for attachment of
the fairing assemblies.
D. Slat Assembly
The slat assembly is airfoil shaped and
combines with the tailboom to form the
exterior surface of the completed tailboom
assembly. The slat assembly is installed into
the open area of the tailboom and forms the
lower side of the two air circulation control
slots. The slat assembly is retained by tension
type titanium fasteners. Slat spacers are
installed in conjunction with the fasteners to
control the distance between the surface of the
tailboom and surface of the slat assembly. At
the forward and aft ends, the exterior and
interior surfaces of the slat assembly fair flush
to the surfaces of the tailboom. The slat
assembly installs to the fuselage attachment
and empennage attachment frames.
The slat assembly consists of the slat outer
skin, the slat airfoil, and tailboom conduit. All