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 placard adjacent to affected Engine Bleed Switch stating
PRE-COOLER CONTROL VALVE INOP - ENGINE BLEED UNUSABLE or PRE-COOLER CONTROL
VALVE INOP OPEN - OBSERVE LIMITATIONS.
4. Journey log / other instructions (texte MEL) :
Print the following information in the journey log sheet.
(LEFT) (RIGHT) (BOTH) PRE-COOLER CONTROL VALVE(S) (INOP - LEAVE BLEED OFF) or
(INOP OPEN - OBSERVE LIMITATIONS)
5. Respecter toutes les restrictions du MEL — ne pas en inventer.
(O) OPERATIONS PROCEDURES — texte MEL :
36-03-02A Inoperative in any position:
NOTE 1 Use of the APU bleed air is limited to 17,000 feet. One air conditioning pack will be
unusable when dispatching with: the left engine bleed unusable and flight altitude greater
than 17,000 feet, the right engine bleed unusable, or both engine bleeds unusable.
NOTE 2: When dispatching with a single engine bleed on for takeoff (airplane pressurized),
V1(MCG) should be determined based on AC packs OFF.
Takeoff performance should be based on AC packs AUTO.
1. Do not dispatch into known or forecast icing conditions.
2. Position the associated engine BLEED switch to OFF.
3. For left engine bleed unusable:
a) At altitudes 17,000 feet and below, operate the left pack using the APU bleed air, the right
pack using the right engine bleed and the isolation valve CLOSE.
b) At altitudes above 17,000 feet, operate with the APU bleed air OFF.
1. Limit altitude to FL 250.
2. Operate the left pack using the right engine bleed, the right pack OFF and isolation
valve OPEN.
4. For right engine bleed unusable:
a) Limit altitude to FL 250.
b) Operate the left pack using the left engine bleed, right pack OFF, and isolation valve CLOSE.
NOTE: At altitudes 17,000 feet and below, increased air flow will occur when flaps are
extended (takeoff and landing) and the APU is used instead of engine bleed to supply
bleed air to the operating pack. Refer to Boeing Operations Manual, NO ENGINE BLEED
TAKEOFF AND LANDING PROCEDURE.
5. For both engine bleeds unusable:
a) Limit altitude to 17,000 feet.
b) Operate the left pack using APU bleed and isolation valve CLOSE. Refer to Boeing Operations
Manual, NO ENGINE BLEED TAKEOFF AND LANDING PROCEDURE.
36-03-02B Inoperative in full open position:
Performance adjustments.
1. Takeoff and landing performance limit weights are reduced by 1120 lb (508 kg) for associated
precooler control valve.
2. Enroute climb limit weight is reduced by 1,530 lb (694 kg) for associated precooler control valve.
3. Apply a fuel mileage decrement of 0.4% for associated engine.
NOTE: Enroute climb penalties are based on single engine operating speeds that approximate
maximum lift-to-drag ratio speed. To account for the difference in level off altitude
when operating at other speeds, multiply the enroute climb weight penalty listed
above by the appropriate Enroute Diversion Speed Effects factor.
Enroute Diversion Speed Effects
(M) MAINTENANCE PROCEDURES — texte MEL (maintenance ; l’équipage vérifie que c’est fait) :
None required.
MAINTENANCE NOTE:
Advise Dispatch. Flight Planning will be affected.
(M#) MAINTENANCE PROCEDURES — personnel maintenance obligatoire — texte MEL :
Deactivate precooler control valve in full open position (AMM 36-00-00/901).
For Precooler Control Valve P/N 3289562-5/-6/-7:
1. Set each engine start lever in the CUTOFF position.
2. Remove pressure from the pneumatic system (AMM 36-00-00/201).
3. Deactivate the leading edge slats in the retracted position (AMM 27-81-00/201).
4. Deactivate the associated thrust reverser (AMM 78-31-00/201).
5. Gain access to the precooler control valve by opening the appropriate thrust reverser
(AMM 78-31-00/201).
6. Remove the supply pressure sense line between the precooler control valve, bleed air regulator,
and intersection manifold duct (AMM 36-12-02/401).
7. On the precooler control valve supply pressure port, remove tubing fitting union J522P53 and
replace with undrilled tubing fitting union C36002-1.
8. Reinstall the supply pressure sense line between the precooler control valve, bleed air regulator,
and intersection manifold duct (AMM 36-12-02/401).
9. Supply pressure to pneumatic system using supply pressure upstream of the PRSOV and perform
a leak check of all distributed tubing fittings using snoop leak detector or equivalent soap solution
(AMM 36-00-00/201).
10. Verify that the visual position indicator on the precooler control valve indicates that the valve is in
the full open position.
11. Remove pressure from the pneumatic system (AMM 36-00-00/201).
12. Close thrust reverser (AMM 78-31-00/201).
13. Activate thrust reverser (AMM 78-31-00/201).
14. Activate leading edge slats (AMM 27-81-00/201).
For Precooler Control valve P/N 63292146-1:
1. Set each engine start lever in the CUTOFF position.
2. Remove pressure from the pneumatic system (AMM 36-00-00/201).
3. Deactivate the leading edge slats in the retracted position (AMM 27-81-00/201).
4. Deactivate the associated thrust reverser (AMM 78-31-00/201).
5. Gain access to the precooler control valve by opening the appropriate thrust reverser (AMM 78-
31-00/201).
6. Remove and reinstall pneumatic lock plug into engaged/locked position. Ensure plug bottoms in
bore. Apply 95-105 in-lb of torque on the pneumatic lock hex.
7. Supply Pressure Upstream of the PRSOV and verify that the valve remain in the full open position
as evidenced by visual inspection.
8. Remove pressure from pneumatic system (AMM 36-00-00/201).
9. Close thrust reverser (AMM 78-31-00/201).
10. Activate thrust reverser (AMM 78-31-00/201).
11. Activate leading edge slats (AMM 27-81-00/201).