(j)
Examine the fan exit fairing for FOD, cracks, dents, and missing screws (AMM 72-31-03/601).
(k)
Examine the linings and fairings of the intermediate case assembly and fan case for these defects (AMM 72-34-01/601, AMM 72-34-03/601, AMM 72-34-04/601, AMM 72-34-05/601, AMM 72-34-06/601): 1) Loose parts
a) Missing parts
2) Nicks, Dents, and Gouges
3) Punctures, and Holes
4) Delamination
5) Cracks
6) Areas with broken or fraying fibers
7) Loose patches
8) Erosion.
NOTE: It is not necessary to examine the Compressor
____ Intermediate Case Fairings or the Fan Exit Liner Segments (Outer) for erosion.
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(2)
Do these steps to examine the turbine exhaust area.
(a)
Examine the inner duct, outer duct, external rails and mount bushings of the turbine exhaust case for bent rails, cracks, dents, and nicks (AMM 72-54-01/601).
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No. 2 - Inlet, Exhaust, and Externals Inspection
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(b)
Examine the struts of the turbine exhaust case for cracks, dents, and nicks (AMM 72-54-01/601).
(c)
Examine the outer duct for oil that is on the inner or outer bottom of the duct (AMM 72-54-01/201).
(d)
Examine the turbine exhaust case, tailpipe, and tail cone area for metal particles. 1) If you find too many particles, do the applicable borescope
procedures in the Engine Gaspath Inspection/Check (AMM 72-00-00/601).
(e)
Examine the 6th-stage LPT blades for nicks, dents, tears, and cracks (AMM 72-53-01/601).
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(3) Do these steps to examine the external components.
CAUTION: REPAIR OR REPLACE THE CRACKED OR BROKEN COOLING AIR TUBES
_______ IN THE TURBINE. THESE DAMAGED COOLING AIR TUBES CAN CAUSE DAMAGE TO THE HIGH PRESSURE TURBINE.
(a) Examine the cooling air tubes in the turbine for cracks (AMM 75-24-00/601).
CAUTION: CORRECT EACH DEFECT IN THE COOLING SYSTEM OF THE LPT
_______ TURBINE CASE. THIS SYSTEM IS NECESSARY TO KEEP THE STRUCTURE COOL. IF THE ENGINE IS CONTINUOUSLY OPERATED WITH A DEFECTIVE COOLING SYSTEM, THIS CAN CAUSE STRUCTURAL DAMAGE.
(b)
Examine the cooling system tubes, valves and cable of the LPT turbine case (AMM 75-24-00/601).
(c)
Examine all of the other tubes for cracks, erosion, blockage, and fretting with other tubes.
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(d) Examine the tubes and nuts for looseness, leaks, and corrosion.
NOTE: When you look for leaks, it's possible to see small
____ quantities of oil near the area of the spinner, the bottom of the fan case, or the attach bolts for the HPC variable vane at the bottom of the engine. The source of this oil is the No. 1 or No. 2 bearing carbon seal assembly.
After the engine windmills or after a long start, the difference in pressure between the carbon seal assemblies and their environment is very high. This high difference in pressure can cause small quantities of oil to leak through the carbon seals and on the external engine parts. This condition is permitted.
Do not remove the engine for this condition. All other conditions of the inspection must be satisfied. There is no limit for the quantity of oil on external engine parts. The limit for the quantity of oil loss is the oil consumption limit.
(e)
Examine the tube and wire bundle clips, clamps, and bolts for loose fits.
(f)
Examine the electrical harness for damage or corrosion.
(g) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 发动机 ENGINE 1(28)
