Section 7
Description of the Airplane and Systems
Columbia 400 (LC41-550FG)
RC050002
Initial Issue of Manual: November 10, 2004
7-8
Latest Revision Level/Date: -/11-10-2004
AIRFRAME AND RELATED ITEMS
The Lancair Columbia 400 (LC41-550FG) is a pre-molded, composite built, semi-monocoque,
four seat, single engine, low wing, tricycle design airplane. The airplane is certified in the utility
category and is used primarily for transportation and related general aviation uses.
BASIC CONSTRUCTION TECHNIQUES
The construction process used to build the shell or outer surfaces of the fuselage, wing, and most
control surfaces involves creating a honeycomb sandwich. The sandwich consists of outer layers
of pre-preg fiberglass around a honeycomb interior. The term “pre-preg fiberglass” means the
manufacturer impregnates the fibrous material with catalyzed epoxy resin. This process ensures
consistency in surface thickness and strength. The honeycomb sandwich is assembled in molds
of the wing, fuselage, and control surfaces. Air pressure is used during the heat curing procedure
to ensure a tight bond. Other structural components of the airplane, like ribs, bulkheads, and
spars, are constructed in the same manner. In areas where added structural strength is needed,
such as the wing spars, carbon fibers are added to the honeycomb sandwich.
Fuselage
–
The fuselage is built in two halves, the left and right sides; each side contains the
area from the firewall back to and including the vertical stabilizer. The bulkheads are inserted
into the right side of the fuselage through a process known as bonding. The two fuselage halves
are bonded together, and the floors are bonded in after fuselage halves are joined. Before the
fuselage is assembled into one unit, cables, control actuating systems, and conduits are added
because of the ease in access. To prevent damage to the leading edge of the vertical stabilizer,
anti-erosion tape may be installed.
Wings and Fuel Tanks
– The bottom of the wing is one continuous piece. The spars are placed
in the bottom wing and bonded to the bottom inside surface. Next, the ribs are inserted and
bonded to the inside surfaces of the bottom wing and to the spars. Finally, after wires, conduits,
and control tubes are inserted, the two top wing halves are bonded to the bottom wing and all the
spars and ribs. The airplane has integral fuel tanks, commonly referred to as a “wet wing.” The
ribs, spars, and wing surfaces are the containment walls of the fuel tanks. All interior seams and
surfaces within the fuel tanks are sealed with a fuel impervious substance. The wing cuffs
(specially shaped pieces of composite material) are bonded to the outboard leading edge of the
wing to increase the camber, or curvature, of the airfoil. This improves the slow-flight and stall
characteristics of the wing. To prevent damage to the leading edge of the wing, anti-erosion tape
may be installed.
Horizontal Stabilizer
– The horizontal stabilizer is two separate halves bonded to two
horizontal tubes that are bonded to the fuselage. The shear webs and ribs are bonded into the
inside surface of the lower skin and the upper skin is then bonded to the lower assembly. To
prevent damage to the leading edge of the horizontal stabilizer, anti-erosion tape may be
installed.
FLIGHT CONTROLS
Ailerons
– The ailerons are of one-piece construction
with most of the stresses carried by the
control surface. The end caps and drive rib that are used to mount the control’s actuating
hardware provide additional structural support. The aileron control system is operated through a