the ACM.

 (g)  
Remove and examine one of the two Mix Muff ducts (AMM 21-21-00/001). 1) If you find volcanic ash in one of the mix muff ducts,

 remove and clean both of the mix muff ducts.

 (h)  
Remove and examine the Cabin Air Supply Check Valves (AMM 21-51-05/401). 1) If you find volcanic ash in the valves, clean or replace

 the valves.

 (i)  
Remove and examine the Pack Temperature Control Valves (AMM 21-61-21/401). 1) If you find volcanic ash in the control valves, clean or

 replace the valves.

 (j)
Remove and examine the Air Mix Valves (AMM 21-61-11/401).

 1)  If you find volcanic ash in the valves, clean or replace the valves.
 S 212-025
 (6)  Examine the pneumatic system.
 (a)  
Remove the bleed air precoolers (heat exchanger)
 (AMM 36-12-25/401) and examine it for ash.

 (b)  
If there is ash in the bleed air precooler, examine the following components for ash: 1) the high stage valves (AMM 36-11-85/401) 2) the pressure regulating and shutoff valves (PR/SOVs)

 (AMM 36-11-15/401) 3) the bleed air check valves (AMM 36-11-35/401) 4) the starter control valves, if it is necessary
 (AMM 80-11-03/401) 5) the precooler control valves (AMM 36-12-35/401) 6) the isolation valve (AMM 36-11-25/401) 7) the APU check valve (AMM 36-11-51/401)
 a) Examine the APU bleed air (shutoff) valve for ash. b) Examine the ground air connector for ash. 8) the nose cowl TAI valves (AMM 30-21-11/401) a) Do a check of the duct pressure transmitters
 (AMM 36-21-11/401). 9) the high stage regulators (AMM 36-11-86/401) 10) the bleed air regulators (AMM 36-11-16/401) 11) the WTAI solenoid valves (AMM 30-11-13/401)
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 05-51-57
 ALL  ú ú 03 Page 206 ú Mar 12/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
 12) the 450 degree F thermostat (AMM 36-12-55/401) 13) the precooler control valve sensor (AMM 36-12-35/401)
 S 212-026
 (7)  
Examine the external light for abrasion.

 S 212-027

 (8)  
Examine the fuel system.

 (a)  
Look for ash in a fuel sample from each fuel tank sump (AMM 12-11-00/301).

 (b)  
Look for ash in a fuel sample from each surge tank sump (if there is fuel) (AMM 12-11-00/301).

 (c)  
Look for ash in each surge tank (AMM 28-11-11/401).

 S 212-028
 (9)  If there is ash in the passenger and control cabin, examine the oxygen system.
 (a)  
Remove the stowage boxes for the mask and regulator and look for ash.

 (b)  
Examine portable oxygen masks for ash.

 (c)  
Examine the passenger and crew oxygen masks for ash.

 S 212-029
 (10) Examine the auxiliary power unit (APU).
 (a)  
Examine the inlet and exhaust ducts for ash.

 (b)  
If there is ash in the APU inlet or exhaust ducts, look for ash as you remove these parts: 1) the fuel filter (AMM 49-31-22/401) 2) the cooling fan inlet screen (AMM 49-51-00/201) 3) the cooling air shutoff valve filter (AMM 49-51-22/401) 4) the differential air pressure regulator filter

 (AMM 49-52-21/301) 5) the compressor discharge pressure orificed T-fitting (AMM 49-52-91/701) 6) the oil filter (AMM 49-91-12/401)
 S 212-030
 (11) If there is ash in the Bleed Air Filter, examine the potable water system.
 (a)  
Remove the bleed air filter (AMM 38-41-11) and look for ash.

 (b)  
If there is ash in the air filter, do these steps:
 1) Look for ash in a sample from water tanks

 (AMM 38-11-00/001). 2) Remove the pressurization check valves and look for ash. 3) Remove the water quantity transmitters (AMM 38-11-21/401)
 and look for ash.
 S 212-031
 (12) Examine the smoke detectors for ash (AMM 5-51-21/201).
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 05-51-57
 ALL  ú ú 05 Page 207 ú Mar 12/02
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：737-300 400 500 AMM 飛機維護手冊 TIME LIMITS/MAINTENANCE CHE(58)