Fuel

Table of Contents:-

Normal Operations:

Alternate Operations:
  • Inoperative Fuel Quantity Indicator
  • Fuel Configuration Light Illuminated
  • Both Main Tank Fuel Boost Pump Low Prices Lights Flashing
  • Failure of Boost, Override/Jettison or Jettison Pump
  • Override/Jettison Pump Failed On
  • Fuel Quantity Indicator Failure
  • Fuel Temperature Low

Controls and Indicators:
  • Fuel Measuring
  • Tank to Engine Fuel Feed
  • Surge Tank Protection
  • Fuel Crossfeed
  • Fuel Heating
  • Fuel Jettison
  • Fueling Override
  • BF Goodrich Digital Fuel Gauges
  • BF Goodrich Digital Fuel Tank Quantity Indicators
  • BF Goodrich Digital Gross Weight/Total Fuel Indicator
  • Smiths Digital Fuel Gauges
  • Smiths Digital Fuel Totalizer
  • Centre Tank Auxiliary Fuel
  • Centre Tank Auxiliary Fuel Isolation Valve Manual Control

Schematics:
  • Fuel System

Supplementary Information:
  • General
  • Fueling / Defueling
  • Fuel Quantity Measuring
  • Measuring Stick
  • Fuel Tank Vent System
  • Surge Tanks
  • Fuel Jettison
  • Unjettisonable Fuel
  • Fuel Quantity Indications
  • Smiths Digital Auxiliary Fuel
  • Centre Tank Auxiliary Fuel
  • BF Goodrich FQIS Diagnostic Information

Limitations





Normal Operations

Normal Fuel Management Procedures (Refer to Chapter 4)

Unbalanced Fuel:
If an engine fuel leak is suspected, accomplish the ENGINE FUEL LEAK procedure.


Alternate Operations

Inoperative Fuel Quantity Indicator:
No indicator movement on fuel quantity indicator(s) when fuel quantity test switch depressed.
The Fuel Quantity Indicator displays "ERR 0".  Pressing the Fuel Quantity Test Switch under these conditions further interrogates the system and a numerical code 1-10 displays to further define the problem.

Fuel Configuration Light Illuminated
Both Main Tank Fuel Boost Pump Low Prices Lights Flashing
Failure of Boost, Override/Jettison or Jettison Pump
Override/Jettison Pump Failed On
Fuel Quantity Indicator Failure
Fuel Temperature Low


Controls and Indicators

Fuel Measuring:


Gross Weight / Total Fuel Weight Indicator:


The zero-fuel weight is added to the indicated total fuel weight.
Pull out the knob and set the total of these two figures into the gross weight window.
Check weight and balance "KG x 1000" indicator in agreement.


Total Fuel Window:

Reflects the total of the individual tank fuel indicators.  Both indicator reading decrease as fuel is consumed.



Tank to Engine Fuel Feed
Surge Tank Protection
Fuel Crossfeed
Fuel Heating
Fuel Jettison
Fueling Override
BF Goodrich Digital Fuel Gauges
BF Goodrich Digital Fuel Tank Quantity Indicators
BF Goodrich Digital Gross Weight/Total Fuel Indicator
Smiths Digital Fuel Gauges
Smiths Digital Fuel Totalizer
Centre Tank Auxiliary Fuel
Centre Tank Auxiliary Fuel Isolation Valve Manual Control


Schematics
Fuel System


Supplementary Information

General:

All fuel is contained within sealed wing areas and delivered to the engine fuel system under positive pressure by AC driven boost pumps.


Fueling / Defueling:

Rapid fueling and defueling is provided by two receptacles at each of two fueling stations, one in each wing.
A volumetric shutoff system is used during fueling to automatically close the fueling valve in each fuel tank when the fuel reaches a preset volume.
Selection of the tanks to be fueled and the final quantity to be in each tank can be controlled from the left-hand fueling station or from the F/Es station.  Overwing fill ports are provided for the main wing tanks only.
Note:  Jettison valves and jettison pumps should not be operated during fueling operations when the fuel source is external to the airplane.  Preflight procedures which would conflict with this caution must be delayed until external fuel pressure sources are disconnected


Fuel Quantity Measuring:

The electronic fuel measuring equipment is a capacitance system.
It reads the fuel by volume and acts upon the total fuel and gross weight indicator.
The fuel quantity indicating system is also used in conjunction with the volumetric shutoff system to actuate fuel shutoff during fueling.

Measuring Stick:

Measuring sticks mounted in the bottom of each tank provide a mechanical means of measuring fuel quantity in a tank.
To obtain the reading rotate the measuring stick 90 degrees counterclockwise and pull out the stick.
Gently push back in until the float magnet is felt to grab the stick magnet, then obtain reading at flush wing reference plane.


Fuel Tank Vent System:

The fuel vent system provides positive venting of the fuel tanks to the atmosphere during all attitudes of the airplane.
Fuel tank vent ports are positioned so that at least one port is open to the expansion area at all times.
Fuel vent float valves located near the top of the fuel tanks prevent fueld from entering the vent system during airplace attitude changes.
Vent outlets are located near the wing tips in the surge tank vent line.


Surge Tanks:

A surge tank in each wing tip provides expansion chambers for excess fuel due to overfilling or thermal expansion.
Surge tank fuel is drained back in the main inboard fuel tanks.
Fuel may be vented overboard, dependant upon the quantity of fuel in the surge tank.


Fuel Jettison:

The fuel jettison system provides a means of rapid weight reduction in flight.
Fuel may be jettisoned with gear and/or flaps extended.


Unjettisonable Fuel:

The jettison pumps incorporate standpipes which ensure a reserve fuel supply for emergency operation after jettison.


Fuel Quantity Indications
Smiths Digital Auxiliary Fuel:
Smiths Fuel Quantity Indicators have a self-test feature which displays an indication of a discrepancy or failure.  The legend "ERR" indicates a problem which degrades the indicator's accuracy, but it is still usable.  The legend "ERR 0" indicates a major failure and the indicator is inoperative.
Pressing the fuel quantity Test Switch under these conditions further interrogates the system, and a numerical code 1-10 displays to further define the problem. Maintenance personnel use this numerical code.
The Gross Weight/Total Fuel indicator compensates for loss of input from an inoperative main or reserve tank by adding the amount of fuel remaining in the opposite, corresponding tank. 
The Gross Weight/Total Fuel indicator displays "ERR" if this occurs.
With loss of inputs from any two main or reserve tanks, the indicator is inoperative and displays "ERR 0".
Loss of input from the CWT results in the
Gross Weight/Total Fuel indicator being in error by the amount of fuel in the CWT.  "ERR" displays.


Centre Tank Auxiliary Fuel:

A supplemental fuel tank is installed in the aft section of the forward cargo compartment.
Fuel from this tank is transferred to the CWT by two pumps through an isolation valve, a fuelling valve and a transfer shuttoff valve.
The isolation and fuelling valves are open when fuel is pumped from the Centre Auxiliary tank and during fuelling of the tank.
A shutoff valve test is provided to check operation of the transfer shuttoff valve which prevents overfill of the CWT.
While normally operated electrically, manual operation of the isolation valve is also possible using the manual control located under the cabin floor in the left aisle approximately 13 feet aft of Door 2 Left.
Simultaneous transfer of fuel from the Centre Auxiliary Fuel Tank and the Fuel Jettison is not possible.


BF Goodrich FQIS Diagnostic Information:

Individual Tank Indicator(s) displays fuel quantity and ACC5 and Total Fuel/Gross Weight Indicator operates normally:
  • Potential degraded accuracy problem detected
  • Indicator is operational log affected tank(s) identity and ACC5 message for future maintenace action.

All indicators display -Ab constantly:
  • Loss of ARINC data from FQIS processor.
  • Reset FQIS processor by cycling 28V FQIS power.  If problem persists, notify maintenance.
Individual Tank Indicator(s) displays fuel quantity normally and after indicator test displays -Ab-, -A-, or -b- :
  • Loss of one channel of ARINC data from FQIS processor
  • Reset FQIS processor by cycling 28V FQIS power.  If problem persists, indicator(s) is operational log affected tank(s) identify and -a- or -b- message for future maintenance action.

Individual Tank Indicator(s) display id Fail:
  • Incorrect / faulted Indicator(s) ID pin Jumpers or Indicator(s) failure.
  • Notify maintenance to:  1) replace failed individual Tank Indicator(s) or, 2) check pin jumpering.

Individual Tank Indicator(s) present an Abnormal Display and Total Fuel/Gross Weight Indicator operates Normally:
  • Individual Tank Indicator Failure(s)
  • Replace blank indicator(s)


Total Fuel/Gross Weight Indicator presents an Abnormal Display and ALL Individual Tank Indicators operation Normally:
  • Total Fuel/Gross Weight Indicator failure
  • Replace Total Fuel/Gross Weight Indicator

One or more individual Tank Indicators Blank and
Total Fuel/Gross Weight Indicator Blanks:
  • Fuel Quantity Gauging Channel (FQC) failure(s)
  • Log failed channel(s) identify and notify maintenance for assitance.


An Abnormal Display in any display presentation resulting from faulty indicator operation and includes missing or incomplete digits.



Fuel limitations:


Less than 2000lbs in any main tank DO NOT exceed 8° nose up body angle.


Max Imbalance X ship Sym tanks: 500kgs. 


Jettison Max Imbalance 2000kgs


Max Fuel Temp: +54.5C (130F)        +43C (110F) JP4


Min Fuel Temp: Fuel freeze point +3C above freezing point of fuel used:


            Jet A: -40C / JetA&A1Mx: -43C / JP5-46C / Jet A1 JP8 -47C / Jet B: -50C

 


Centre Wing Tank:       17,000 US Gal            120,700 lbs       52160 kgs

Main Tank 1 or 4:           4,253 US Gal            30,196  lbs       13125 kgs


          Main Tank 2 or 3:        12,300 US Gal            87,330  lbs         38125 kgs

Reserve Tank 1 or 4:        500 US Gal            3,550    lbs          1550 kgs

          Total All Tanks:           51,106 US Gal            362,852 lbs      157,760 kgs










Flight Engineer - Fuel Control Panel




FE's Fuel Jettison Panel - (Always action top to bottom)




CWT


What is jet fuel ? http://en.wikipedia.org/wiki/Jet_fuel


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