(a)
Visually examine these areas for burned areas, distortion,
metal particles, or signs of upstream blade or vane damage:
the turbine exhaust sleeve, exhaust plug, and the area
immediately aft of the 6th-stage turbine blades.
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No. 4 - Engine Overtemperature Inspection
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(b) If the visual inspection is not satisfactory, do the borescope inspection (AMM 72-00-00/601, Engine Gaspath Inspection).
S 226-069-N00
(5)
Do the Hot Section Inspection (if it is necessary).
(a)
Open the fan cowl panels (AMM 71-11-04/201).
WARNING: DO THE THRUST REVERSER DEACTIVATION PROCEDURE TO PREVENT
_______ THE OPERATION OF THE THRUST REVERSER. THE ACCIDENTAL OPERATION OF THE THRUST REVERSER CAN CAUSE INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT.
(b)
Do this procedure: Thrust Reverser Deactivation for Ground Maintenance (AMM 78-31-00/201).
(c)
Open the core cowl panels (AMM 71-11-06/201).
WARNING: OBEY THE INSTRUCTIONS IN AMM 78-31-00/201 WHEN YOU OPEN
_______ THE THRUST REVERSERS. IF YOU DO NOT OBEY THE INSTRUCTIONS, INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR.
(d)
Open the thrust reversers (AMM 78-31-00/201).
(e)
Examine the high tension leads of the igniter plug
(AMM 74-21-01/601).
NOTE: When the operation of the engine is stopped too quickly,
____ sufficient cooling air is kept from the igniters. The heat goes through the igniter plug and the high tension leads. That condition can cause deterioration of the rubber insulation, which can then make arcs at the terminal area.
(f) Do the borescope inspections that follow (AMM 72-00-00/601):
1) Examine the combustion lining for signs of cracks, burned areas, too much heat, erosion, distortion, and areas that are not correctly aligned.
2) Examine also for worn pins and for worn areas at the nozzles and the mounts. 3) Examine the fuel nozzles for coke, cracks, distortion, worn areas, broken open areas, and burned holes. 4) Examine the 1st-stage HPT vanes for cracks, FOD, erosion, corrosion, burned marks, and distortion. 5) Examine the 1st-stage HPT blades for cracks, FOD, tip rub, erosion, and corrosion. 6) Examine the 1st-stage HPT blades for discoloration that has the shape of concentric circles on the airfoil surface.
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////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
No. 4 - Engine Overtemperature Inspection
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7) Examine each 2nd-stage HPT blade for cracks, tip rub, erosion, FOD, and blade extension.
NOTE: A sign of airfoil extension is when the length of
____ the blade is increased and the perimeter of the middle is decreased.
8) Examine the 3rd-stage LPT blades and vanes for cracks, FOD, tip rub, and erosion. a) If there has been a sudden increase in EGT, check for a
possible missing or liberated LPT 3rd-stage outer transition duct segment. b) No missing or liberated outer transition duct segments are permitted.
E. Steps that are Necessary after the Removal of the Engine.
S 216-185-N00
(1)
Do the steps that are necessary after the Removal of the Engine.
(a)
Put a tag, with the data that follows, on the engine or the section of the engine that you will replace. 1) The maximum temperature that occurred 2) The time during which the overtemperature occurred 3) If the overtemperature occurred at steady state or at surge
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