Fuel

Question 1

Where is fuel stored?

Answer 1

In the wing tanks that are part of the internal wing structure; there are no bladders.

Question 2

Describe location and capacity of
hopper tanks.

Answer 2

Inside each wing tank, adjacent to
centerline rib, is a hopper that holds
approximately 1100 pounds of fuel for
G500 and 1170 pounds for G600.

Question 3

What’s the purpose of ventilation
system?

Answer 3

It protects from over and under
pressurization by allowing air, fuel vapors,
and fuel to move about or flow freely.

Question 4

Vent tubes are connected to empty chamber or plenum which is located at wing tip, just outboard of fuel tanks. What’s the capacity of plenum and vent tubes?

Answer 4

They provide for 2% fuel expansion

Question 5

What’s indicated if HIGH LEVEL
WARN lights illuminate on refuel
panel?

Answer 5

High level sensors are wet and Fuel Quantity Signal Conditioner (FQSC) has
closed respective refueling valve

Question 6

What happens when REMOTE FUEL
SHUTOFF switch is selected on
OHPTS?

Answer 6

Switch label turns green and both pressure
fueling shutoff valves close

Question 7

What are the different methods of
refueling?

Answer 7

Single point pressure fueling or over-the-wing

G600 Fuel Capacity Pressure refueling: 41,500lbs.
Overwing gravity refueling: 33,500 lbs.

G500 Fuel Capacity Pressure refueling: 30,250 lbs.
Overwing gravity refueling: 22,500 lbs.

Question 8

How is automatic refueling
controlled?

Answer 8

From Touch Screen Controller (TSC) or
refuel panel located at fueling station

Question 9

How many methods are there for
maintaining fuel balance?

Answer 9

Two: by moving fuel from hopper to
hopper through intertank valve, or by
directing fuel from one hopper to opposite
engine using crossflow valve.

Question 10

How many boost pumps does GVII
have and where are they located?

Answer 10

There are four (4) identical and
interchangeable fuel boost pumps in main
wheel wells attached to aft portion of each
hopper.

Question 11

What’s the purpose of fuel boost
pumps?

Answer 11

They deliver fuel to engines and APU at
relatively low pressure through various
fuel distribution lines and shutoff valves.

Question 12

How does fuel flow into hopper?

Answer 12

Through ejector pumps and flapper type
check valves

Question 13

How do ejectors operate?

Answer 13

They require only fuel boost pump
pressure to operate: they’re low pressure,
high volume jet pumps. As long as there’s
boost pump pressure, ejector pumps
deliver steady flow of fuel into each
hopper.

Question 14

What happens when crossflow valve
is opened?

Answer 14

Boost pump manifolds are joined allowing
pressurized fuel from functioning pumps
to flow to both engines.

Question 15

When do white Fuel Crossflow Valve
Open and Fuel Inter Tank Valve Open
CAS messages change to blue?

Answer 15

After five (5) minutes

Question 16

What’s the warning associated with
use of crossflow valve?

Answer 16

You should always OPEN crossflow valve
before turning OFF both boost pumps on
one side. Without boosted pressure above
20,000’, Gulfstream says the engine will
run erratically and flameout.

Question 17

What happens when intertank valve is
opened?

Answer 17

Fuel gravity flows between two hopper
tanks allowing the tanks to balance

Question 18

What action does Gulfstream
recommend before opening intertank
valve?

Answer 18

Establish sideslip (i.e., rudder trim in
direction of heavy tank)

Question 19

What happens when Fuel Return
switch defaults to green Auto on
power up?

Answer 19

The system allows heated fuel into tanks
when fuel tank temperature is ≤ 0°C and
altitude ≥ 30,000’. When tank
temperatures warm to approximately
+10°C, heated fuel stops flowing to the tanks.

Question 20

There are several abnormal conditions which inhibit heated fuel return system from operating (e.g., fire
handle pulled, low fuel pressure signal, low fuel quantity signal). What
types of normal conditions inhibit this system from operating?

Answer 20

Cross valve open or engine at high power settings