Table 2-3. Fuel Sump Drain Locations
Leading Edge Tank
Outboard of nacelle, underside of wing
Underside of wing, forward of aileron
Firewall Fuel Filter
Underside of cowling forward of firewall
Bottom center of nacelle forward of wheel well
Gravity Feed Line
Aft of wheel well
At wing root, just forward of the flap
tion. An internal float switch actuates an electric
scavenger pump which delivers the fuel to the fuel
purge line just aft of the fuel purge shutoff valve. A
check valve in the line prevents the backflow of fuel
during engine purging. The circuit breaker for both
pumps is located in the fuel section of the overhead
circuit breaker panel; placarded SCAVENGER
PUMP. A vent line, plumbed from the top of the
collector tank, is routed through an inline flame
arrestor and then downward to a drain manifold on
the underside of the nacelle.
fer of auxiliary fuel, which is automatically con-
trolled, the nacelle tanks are maintained full. A
check valve in the gravity feed line from the out-
board wing prevents reverse fuel flow. Normal grav-
ity transfer of the main wing fuel into the nacelle
tanks will begin when auxiliary fuel is exhausted.
The system will gravity feed fuel only to its respec-
tive nacelle tank, i.e. left or right (fig. 2-16). Fuel
will not gravity feed through the crossfeed system.
i. Fuel Vent System. Each fuel system is
vented through two ram vents located on the under-
side of the wing adjacent to the nacelle. To prevent
icing of the vent system, one vent is recessed into
the wing and the backup vent protrudes out from
the wing and contains a heating element. The vent
line at the nacelle contains an inline flame arrestor.
j. Engine Oil-to-Fuel Heat Exchanger. A n
engine oil-to-fuel heat exchanger, located on each
engine accessory case, operates continuously and
automatically to heat the fuel delivered to the engine
sufficiently to prevent the freezing of any water
which it might contain. The temperature of the
delivered fuel is thermostatically regulated to remain
between 21°C and 32°C.
b. Operation With Failed Engine-Driven Boost
Pump or Standby Pump. Two pumps in each fuel
system provide inlet head pressure to the engine-
driven primary high-pressure fuel pump. If crossfeed
is used, a third pump, the standby fuel pump from
the opposite system, will supply the required pres-
sure. Operation under this condition will result in an
unbalanced fuel load as fuel from one system will be
supplied to both engines while all fuel from the sys-
tem with the failed engine driven and standby boost
pumps will remain unused. A triple failure, which is
highly unlikely, would result in the engine driven
primary pump operating without inlet head pres-
sure. Should this situation occur, the affected engine
can continue to operate from its own fuel supply on
its engine-driven primary high-pressure fuel pump.
2-34. FUEL SYSTEM MANAGEMENT.
2-35. FERRY FUEL SYSTEM.
a. Fuel Transfer System. When the auxiliary
tanks are filled, they will be used first. During trans-
Provisions are installed for connection to long
range fuel cells.
Section V. FLIGHT CONTROLS
The aircrafts primary flight control systems
consist of conventional rudder, elevator and aileron
control surfaces. These surfaces are manually oper-
ated from the cockpit through mechanical linkage
using a control wheel for the ailerons and elevators,
and adjustable rudder/brake pedals for the rudder.
Both the pilot and copilot have flight controls. Trim
control for the rudder, elevator and ailerons is
accomplished through a manually actuated cable-
drum system for each set of control surfaces. The
autopilot has provisions for controlling the position
of the ailerons, elevators, and rudder. Chapter 3
describes the operation of the autopilot system.