Fuel

Question 1

Where is the fuel stored?

Answer 1

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

Question 2

Describe the location and capacity of hopper tanks.

Answer 2

Inside each wing tank, adjacent to the centerline rib, is a hopper that holds approximately 190 gallons of fuel.

Question 3

What’s the purpose of the fuel 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

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

Answer 4

They provide for 2% fuel expansion

Question 5

What’s indicated if the red light illuminates on the refuel panel?

Answer 5

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

Question 6

What happens when the REMOTE FUELING SHUTOFF switch is selected to CLSD?

Answer 6

Both pressure fueling shutoff valves close and the CLSD legend illuminates in blue

Question 7

What are the different methods of refueling?

Answer 7

Single point pressure fueling or over-the-wing

Question 8

How is automatic refueling controlled?

Answer 8

Via the Standby Multifunction Controller (SMC) or a refuel panel located at the fueling station.

Question 9

How many methods are there for maintaining fuel balance?

Answer 9

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

Question 10

How many boost pumps does the G650 have and where are they located?

Answer 10

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

Question 11

What’s the purpose of the fuel boost pumps?

Answer 11

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

Question 12

How does fuel flow into the hopper?

Answer 12

Ejector pumps

Three one way flapper type check valves

Question 13

How do the fuel 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 the fuel crossflow valve is opened?

Answer 14

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

Question 15

When does the color of the blue Fuel Crossflow Valve Open message change to amber?

Answer 15

After five (5) minutes

Question 16

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

Answer 16

You should always OPEN the 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 the fuel intertank valve is opened?

Answer 17

Fuel can gravity flow between the two hopper tanks allowing the tanks to balance

Question 18

What action does Gulfstream
recommend before opening the fuel intertank valve?

Answer 18

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

Question 19

What happens when the FUEL RETURN switch is selected to AUTO?

Answer 19

The OFF caption extinguishes and the system allows heated fuel into the tanks when fuel tank temperature is approximately 0°C or colder. When tank temperatures warm to approximately +10°C, heated fuel stops flowing to the tanks.

Question 20

There are several abnormal conditions which inhibit the 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

Crossflow valve open or engine at high power setting