EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 72-31-02
 ALL  ú ú N01 Page 607 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
(b)  If you find a shroud(s) that has cracks do the steps that follow: 1) Examine the shrouds of all the fan blades for cracks.
 a)  Carefully examine the shroud radius (Area C) that is on the concave side of the airfoil.
 NOTE: It is very important to examine the side of
____ Area C that is nearest to the root of the blade.
 2)  Remove the damaged fan blade(s), the blades that are on each side of it, and the matched moment blade of each removed blade.
 NOTE: For each fan blade that has a shrouds that has
____ cracks, you must remove six fan blades.
 (c)  If you find a shroud(s) that is broken (fractured) or missing, e do the steps that follow: 1) Remove and replace the damaged blade and two adjacent
 blades along with their three moment weighed pairs. Report
 the serial numbers of the adjacent blades. 2) Lubricate the shrouds and dispatch the aircraft. 3) Obey a 25 hour flyback limit until you do a NDI inspection
 of all concave shrouds per PW4ENG 72-478. 4) NDI reinspect all concave shrouds per SB PW4ENG 72-478 within 40 cycle. 5) Visually inspect at every 1/2 A-check (lubrication interval).
 NOTE: This applies to the pre SB PW4ENG 72-536 fan
____ rotors only. Inspect all phase III and post SB PW4ENG 72-536 fan rotors at every A-check.
 6) NDI reinspect at next C-check.
 7) NDI reinspect at all overhauls.
 8) Notify P&W of any cracked fan blades found reporting:

 -
Total time

 -
Total cycles

 -
Part number and change letter

 -
Part serial number and heat code _ Engine serial number

 -Cycles since last inspection.
 S 216-030-N00
 (2)  
Examine Area A (shroud contact edge) for damage.

 (a)  
No damage or blends are permitted in Area A.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 72-31-02
 ALL  ú ú N01 Page 608 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
S 216-031-N00
 (3)  
Examine Area B (hardface surface of the shroud) for cracks, worn areas or damage on the hardface.

 (a)  
With the rotor stopped and not held, manually push one blade rearward in the blade slot at the 12 o'clock position and pull the adjacent blade forward.

 NOTE: You can hit the thick part of the shroud with your hand
____ or with a soft rubber mallet to release the blades.
 (b) Examine the shrouds for worn areas on the mating surfaces.
 1)  If there are areas where the hardface is worn through, do not use the fan blade.
 NOTE: If the hardface is worn through, the operation of
____ the engine can distort and peen the titanium shroud.
 (c) Chips in the hardface surface which are larger than 0.030 inch
 (0.762 mm) are not permitted.
 (d)  If you think there is a crack, do a fluorescent penetrant inspection. 1) Cracks are not permitted.
 S 216-032-N00
 (4)  
Examine Area C (shroud radius) for damage (Fig. 604).

 (a)  
Repair all damage that is not more than the repair limits (AMM 72-31-02/801). 1) The repairs must not go below the airfoil surface.

 (b)  
Sharp edges are not permitted (AMM 72-31-02/801).

 (c)  
If the damage is more than the blend limits, do not use the fan blade.

 S 216-033-N00
 (5)  
Examine Area D (fillet radius) for damage (Fig. 603).

 (a)  
Isolated damage with rounded bottoms that is less than 0.005 inch (0.127 mm) in depth is serviceable.

 (b)  
No other damage is permitted.

 S 216-034-N00
 (6)  
Examine Area E (shroud upper and lower surfaces) for damage.

 (a)  
No damage is permitted.

 (b)  
You must repair all damage that is less than the repair limits (AMM 72-31-02/801). 1) The maximum depth of a blend is 0.010 inch (0.254 mm).
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 發動機 ENGINE 1(152)