1. Confirmer l’item, la catégorie et le nombre requis dans le MEL officiel (lien PDF).
2. Appliquer les procédures (O) et/ou (M) du MEL avant dispatch — texte officiel ci-dessous.
3. Placard (texte MEL) :
Apply sticker adjacent to affected Fuel Quantity Indicator and to Refueling panel.
4. Journey log / other instructions (texte MEL) :
Print the following information in the journey log sheet.
Main Fuel Tank Fuel Quantity Inoperative: (LEFT)(RIGHT) MAIN FUEL QUANTITY INDICATOR
INOP
5. Respecter toutes les restrictions du MEL — ne pas en inventer.
(O) OPERATIONS PROCEDURES — texte MEL :
1. The MEL requirement to keep track of the fuel burn is intended to ensure that the pilot will notice
an abnormal fuel feed situation and correct the resulting lateral fuel imbalance. The following are
examples of methods that accomplish this requirement and are valid with crossfeed valve closed
or open. Keep the CROSSFEED selector in CLOSED position, unless directed otherwise.
2. The objective of the following procedures is to assure that the fuel being consumed is coming
from the intended tank. A verification of the fuel source can be made by comparing the fuel
quantity change in 6 minutes to 1/10 of the fuel flow on the engine or engines feeding from that
tank. For example, when using center tank fuel, if the rate of quantity decrease in the center
tank is one half of the sum of the fuel flow for the engines, one engine is feeding from a wing
tank.
METHOD I - FOR AIRPLANES WITH FUEL USED INDICATORS:
Continued…
METHOD II - AIRPLANES WITHOUT FUEL USED INDICATORS:
Compare the precomputed fuel remaining against the actual fuel remaining. If the differences
are unaccounted for and exceed 1000 pounds, perform the appropriate procedures to re-
establish the proper fuel distribution.
Computation of fuel remaining can stop at top of descent if it is obvious that one has
adequate fuel remaining. If weather, ATC or other problems cause concern, continue taking
fuel flow and time readings at appropriate intervals.
3. If VNAV capability is desired, enter and periodically update current fuel on board into the FMC.
(M) MAINTENANCE PROCEDURES — texte MEL (maintenance ; l’équipage vérifie que c’est fait) :
None required.
(M#) MAINTENANCE PROCEDURES — personnel maintenance obligatoire — texte MEL :
Fuel Servicing Procedures
Do the fuel servicing procedures when a fuel quantity indicator does not operate (AMM 12-11-00).
This procedure uses a bussing plug jumper harness fabricated per instructions below or obtain pre-
fabricated jumper harness from supplier, Cinch, per Service Letter 737-SL-28-108 for the Main Tank
1 FQIS or Main Tank 2 FQIS deactivation (AMM 28-00-00/901).
• If the main tank fuel quantity indicator blanks intermittently or if the fuel quantity
indicator shows an incorrect fuel quantity or presence of any of these faults (TANK UNIT
Lo-Z OPEN/GND, Hi-Z OP/SHORT TO SHIELD, COMPENSATOR Lo-Z OP/GND,
COMPENSATOR SHORTED or DENSITOMETER SIGNAL FAIL), deactivate the intermittent or
non-functioning FQIS (AMM 28-00-00/901).
• If two of the three tank FQIS indications on the airplane are intermittent or non-
functional, the airplane cannot be dispatched.
1. Open FUEL FUELING CONT, FUEL FUELING IND, FUEL QTY 2 and FUEL QTY 1 circuit breakers on
P6 panel.
2. Disconnect the external fuel tank bussing plug per AMM Task 28-41-41-000-801. For main tank 1
disconnect D11312 or for main tank 2 disconnect D11314.
3. Cap and stow the external fuel tank bussing plug connector and wiring (SWPM 20-10-11,
Section 18).
NOTE: Fold excess wires. Do not coil the wires.
4. Leave the wiring shields connected to ground stud (reference WDM 28-41-11) if the wire can be
safely stowed without damaging the shield ground wire.
5. Install the pre-fabricated bussing plug jumper harness.
a) Connect the jumper harness terminal lug to a ground stud GD3982-ST or GD3950-ST for
main tank 1 at the spar or connect the jumper harness terminal lug to ground stud GD3986-
ST or GD3952-ST for main tank 2 at the spar. Verify that only case or shield grounds are
terminated at the ground stud.
NOTE: Current return ground studs (designated GDXXX-AC or GDXXX-DC) cannot be used.
b) Verify the resistance between each of the following socket contacts to the spar is 1.0 Ohm or
less:
i) For airplanes not equipped with densitometer, connector positions 1, C1, 2, and 3 (Hi-Z,
Hi-Z shield, Lo-Z, and compensator).
ii) For airplanes equipped with densitometer, connector positions 1, 2, C2, 4, 5, C5, 16, 17,
18, 19, 20, and 21 (Hi-Z, Hi-Z shield, Lo-Z, compensator, Sense, sense shield, drive (+),
drive (-), and calibration resistors KR0, KR1, KR2, and KR3).
NOTE: The Hi-Z and sense is verified at the center conductor of the coax contact. The Hi-Z
shield, and sense shield is verified at the outer conductor of the coax contact.
c) Connect the pre-fabricated bussing plug jumper harness to the spar. Install lockwire to attach
bussing plug jumper harness to the jamnut.
NOTE: Fold excess wires. Do not coil the wires.
Continued…
6. Close FUEL FUELING CONT, FUEL FUELING IND, FUEL QTY 2 and FUEL QTY 1 circuit breakers on
P6 panel.
7. Verify that the display on the refuel indicator is blank (does NOT show fuel quantity). Also verify
on the flight deck, CDU does NOT show total fuel quantity and that the fuel is blank in the upper
display.
To fabricate a bussing plug connector jumper harness
Do the following steps to make the pre-fabricated bussing plug connector jumper harness (use an
applicable spare bussing plug connector to make the bussing plug connector jumper harness). The
wire harness must be no longer than 24 inches:
1. Make a shielded wire with a coax contact on one end, using 20 gauge wire (BMS 13-60, type 8 or
type 11, class 1; or BMS 13-48, type 12, class 1).
a) Terminate the wire and the shield to coax contact S283U007-7 (SWPM 20-61-11).
NOTE: These wires will connect to tank connections for Hi-Z and shield.
2. Make two unshielded wires using 20 gauge wire (BMS 13-60, type 10, class 1; or BMS 13-48,
type 31, class 1; or BMS 13-48, type 65, class 1).
a) Terminate one end of each wire to contact BACC47CP2T (SWPM 20-61-11).
NOTE: These wires will connect to tank connections: Lo-Z and compensator.
3. For airplanes equipped with densitometer, make another shielded wire with a coax contact on
one end using 20 gauge wire (BMS 13-60 type 8 or type 11, class 1 or BMS 13-48 type 12,
class 1).
a) Terminate the wire and the shield to coax contact S283U007-7 (SWPM 20-61-11).
NOTE: These wires will connect to tank connections: sense and shield.
4. For airplanes equipped with densitometer, make six additional unshielded wires, using 20 gauge
wire (BMS 13-60, type 10, class 1; or BMS 13-48, type 31, class 1; or BMS 13-48, type 65,
class 1).
a) Terminate one end of each wire to contact BACC47CP2T (SWPM 20-61-11).
NOTE: These wires will connect to tank connections: drive (+), drive (-), and calibration
resistors (KR0, KR1, KR2, and KR3).
5. Terminate the other end of the wires into suitable terminal lugs (SWPM 20-30-11).
NOTE: The following terminal lug configuration contributes to the operation of the suggested
ground stud GD3950-ST or GD3982-ST for main tank 1 and GD3952-ST or GD3986-ST
for main tank 2 (One terminal lug is installed at these locations):
a) With densitometers: three terminal lugs with four wires each (12 wires total).
b) Without densitometers: two terminal lugs with two wires each (4 wires total).
6. Insert the wires with the contacts into bussing plug jumper harness connector (SWPM 20-61-11):
a) For non-densitometer configuration, insert the shielded wire with the coax contact into
connector position 1 (Hi-Z and Hi-Z shield) and insert the unshielded wires into connector
positions 2 and 3 (Lo-Z and compensator).
b) For densitometer configuration, insert the shielded wires with the coax contacts into
connector positions 2 and 5 (Hi-Z and Hi-Z shield; and sense and shield) and insert
unshielded wires into connector positions 1, 4, 16, 17, 18, 19, 20, and 21 (Lo-Z,
compensator, drive (+), drive (-), and calibration resistors KR0, KR1, KR2 and KR3).