SPYDER FUEL/OIL

Standard Fuel System Management procedures are followed until the total fuel quantity reaches (BLANK) pounds resulting in approximately (BLANK) pounds in each main tank. (1S-39, p1)

18,000; 4,500

Low fuel state operations are defined as those operations that result in the airplane landing with less than (BLANK) pounds of fuel. (1S-39, p2)

18,000

Deck angle and maneuver loads become increasingly critical during low fuel state operations if either (BLANK) warning light is illuminated. (1S-39, p2)

MAIN SUMP LOW

Describe fuel tank arrangement: (1.19.1) (p 1-245)

12 tanks, 6 per wing; 4 main, 4 auxiliary and 4 extended range tanks

Usable fuel capacity is? (1.19.1) (p 1-245)

48,897 gallons or ~ 49,000 gallons

What is the purpose of the sump box in the main fuel tanks? (1.19.1.1) (p 1-245)

Provide uninterrupted flow of fuel to the engine during abnormal operating conditions (uncoordinated flight, gusts, sideslips, neg Gs, nose up/down attitudes) and for the outboard main tanks, to provide favorable wing loading at high speeds; contains inboard and outboard fuel tank pumps

Any time the fuel tank pressure is greater than (BLANK) PSI relative to ambient pressure, the primary climb valve opens to vent overboard. Any time the fuel tank pressure drops below (BLANK) PSI, the primary dive valve opens to admit air into the tanks. (1.19.1.2) (p 1-245)

0.7; -0.15

How many electrically driven fuel boost pumps per tank? Which is primary? (1.19.1.3) (p 1-245)

2 per tank; outboard

What are the jettison rates for AUX tanks only, EXT RANGE tanks only, AUX & EXT RANGE tanks (all pumps on)? (1.19.1.5) (p 1-246)

EXT RANGE = 5560 ppm

AUX = 5360 ppm

BOTH = 9000 ppm

What is MAIN TANK LOW Caution CWA? What are the restrictions? (1.19.3.2, 3.79.5) (p 1-248, 3-309)

Outboard main fuel tank is less than 75% full; 280 kts or 0.825 mach (if fuel mismanagement...aka fuel remains in aux or ext range tanks)

What is MAIN SUMP LOW Caution CWA? What are the restrictions? (1.19.3.5, 3.79.2) (p 1-248.1, 3-306)

On when fuel quantity in 1807 lb capacity sump of each outboard main tank (1 or 4) drops below 1600 lbs (warns of possible adverse wing loading); 280kts/0.825 M

What is a VENT FILL light (on FE fuel panel)? (1.19.3.6, 3.79.8) (p 1-248.1, 3-306)

Vent box is about 1/3 full (float switch in vent box closes) Each vent system is terminated at a vent sump in outboard main tanks. A VENT FILL indication will be caused by a faulty main tank fill valve or a faulty auxiliary or extended range refuel valve OR could be a broken heat exchanger or liquid nitrogen pressurization line in the outboard main fuel tank.

How does the Fuel Tank Pressurization system work? (1.19.4.2) (p 1-249)

The fuel tanks are pressurized automatically whenever the dewars contain liquid nitrogen and the isolation valves are open.

Pressure in the fuel tanks is controlled by pressure regulators which maintain a positive pressure

Vent valves prevent overpressure or underpressure

Vent valve assembly consists of a primary and a secondary climb and dive valve.

Primary climb valve opens automatically to vent the fuel tanks at 0.7 to 1.0 PSI because of increased pressure or airplane climbs to a higher altitude.

Primary dive valve opens at - 0.15 to - 0.25 PSI to admit air to relieve fuel tank pressure decrease or rapid descent of the airplane.

If the primary climb or dive valve fails to open:

Secondary climb valve will open automatically to vent the fuel tanks at 1.0 to 1.5 PSI or

Secondary dive valve will open automatically at - 0.25 to - 0.35 PSI to admit air.

If the secondary climb and dive valve fails to open, it can be manually controlled to open both the climb and dive poppets to relieve any overpressure or underpressure when indicated by the fuel tank pressure warning lights on the flight engineer panel.

The primary climb valve opens automatically to vent fuel tanks at 0.7 to 1.0 psi due to: (1.19.4.2) (p 1-249)

Increasing N2 pressure, atmospheric drop or climb to higher altitude

The primary dive valve opens automatically at -0.15 to -0.25 psi to relieve tank pressure due to: (1.19.4.2) (p 1-249)

Lack of N2 or rapid descent

Describe what happens if the primary climb or dive valves fail to open: (1.19.4.2) (p 1-249)

The secondary climb valve will automatically open to vent at 1.0 to 1.5 psi; the secondary dive valve will auto open at -0.25 to -0.35 to admit air

What if the secondary climb or dive valve fails to open? (1.19.4.2) (p 1-249)

It can be manually controlled to open using the climb and dive "poppets" (Vent Valve push buttons)

What hydraulic system powers the Secondary Climb and Dive valves? (1.19.4.2) (p 1-249)

Hydraulic system #1

What does pushing the LEFT WING or RIGHT WING (VENT VALVE) pushbuttons do? (1.19.4.2) (p 1-249)

Manually opens secondary climb/dive valves and fuel tanks for affected wing are vented to atmospheric pressure) (should get VENT OPEN indication) & closes both liquid nitrogen isolation valves (NOTE: pushing the button again will reset the climb and dive valves and open both nitrogen isolation valves.)

When does the WING PRESSURE WARNING (CWA) & FUEL TANK PRESSURE WARNING (FE FSS Panel) light come on? (1.19.4.3, 3.80) (p 1-250)

If tank pressure greater than 2.0 psi or less than - 0.7 psi

What is the problem when you get a FUEL TANK PRESSURE WARNING? What should you do? (1.19.4.3, 3.80) (p 1-250, 3-311)

Primary and secondary climb/dive valves have failed to equalize the pressure between the ambient air and fuel tanks. If the corresponding VENT OPEN light does not come on and the fuel tank pressure warning does not go off, discontinue a climb or descent. Jettison as a last result (no ref).

What is fuel scrubbing and how does it work? (1.19.5) (p 1-250)

Reduces O2 in fuel; it is done in each tank during ground and air refueling

An aspirator draws N2 from the ullage and mixes it with fuel; fuel entering tanks is about 5% O2; ullage stays < 9% O2

The decrease of atmospheric pressure during climb causes the fuel to release a flammable gas which then mixes with the vapors already in the ullage.

The scrubbing subsystem of the Fire Suppression System (FSS) scrubs or reduces the oxygen dissolved in the fuel.

This prevents the release of flammable gas from the fuel thus destroying the inert atmosphere in the fuel tanks.

Fuel scrubbing is accomplished in each tank during ground and air refueling by an aspiscrubbing function.

The aspiscrubbing function scrubs the fuel to such a low level of oxygen concentration that no additional scrubbing is required during climb.

Does the C-5M have a controllable fuel heater system? (1.2.2.3, p 1-30 & 1.20.1.1, p 1-26.6)

No, The fuel-oil heat exchanger uses scavenge oil for heating the fuel to decrease the possibility of icing. The heat exchanger also cools engine oil to an acceptable range, while heating the fuel.

What is the indication and corrective action for a tank boost pump failure? (3.79.1) (p 3-306)

PRESS LOW light on FE Fuel Panel

If the outboard boost pump (primary pump) in any tank fails, turn on the inboard boost pump and place the outboard boost pump switch in the OFF position.

If both pumps fail in Main tanks, then the engine will suction feed

What are the suction feed limits? (5.4.9.1) (p 5-10)

JP8: Climb Outboard - 32,000 ft Inboard - 40,000 ft

JP4: Climb Outboard - 16,000 ft Inboard - 20,000 ft

Cruise: no suction feed limits for non-maneuvering cruise

Heavyweight is defined as gross weights above (BLANK) pounds. (5.6.1) (p 5-16)

635,850

What is the maximum fuel load of the C-5? (5.6.2, Figure 5-5)

332,500 lbs