C. Fuel transfer (refer to NFM F O - 9 )
1. Gravity feed from fuselage to wing tanks.
2. Transfer ejector pumps, in wings use motive flow to direct fuel to boost pumps.
3. LH/RH wing mounted centrifugal boost pumps (electrical driven) - Energized when
respective Engine Master ON. Provide pressurized (17-30 psi) fuel to engine driven pump.
200# unavailable if a boost pump fails. (400# if both fail)
4. Engine-driven two-element pump (centrifugal boost and gear) delivers high pressure
fuel to the engine fuel control. FUEL LOW PRESS light if the pressure difference across the
centrifugal pump < 6 psi.
(dump on shutdown).
6. No fuel jettison capability.
7. Normal fuel flow 300# to 3300#/hr. On start fuel flow limits 260# - 600#/hr.
D. Fuel shutoff valve
1. Downstream of wing mounted electric boost pumps.
2. Check open when Engine Master ON (FUEL SHUTOFF FAIL light).
E. Fuel filter
1. Between centrifugal and gear elements of the engine-driven pump.
2. FUEL FILTER BLOCK light on if differential exceeds 7-8 psi; bypassed if differential
exceeds 9-11 psi.
F. Fuel heat
1. Use when fuel temp at or below 0 C or with FUEL FILTER BLOCK light on. One
minute time limit each 30 minutes (may overheat oil). Do not use during T/O or landing.
G. FUEL X-FEED & TANK SEL Switch
1. NORM: Each side is independent: the right wing tank provides fuel for the right
engine, and the left wing tank provides fuel for the left engine. Both tank and pump x-feed
valves closed, both wing mounted boost pumps ON.
2. LH/RH TANK: Used for normal fuel balancing, select HEAVY tank. Pump x-feed
valve opens (but the wing tank x-feed valve stays closed). Boost pump in the wing opposite
the selected side is de-energized.