Service difficulty report · Control Module · Boeing 7379

Difficulty date
April 20, 2026
Submitted
April 22, 2026
Operation
Air carrier
Aircraft
N77588
Make and model
Boeing 7379
Aircraft serial
43446
Aircraft time
5,190 hours, 1,681 cycles
Part
Control Module
Part number
1742F9
Part serial
3766
Condition
Faulty
Location
Zone 900
Part time
5,177 hours, 1,678 cycles
Stage of operation
CR
How discovered
O
Nature of condition
J
Precautionary procedure
A

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

CREW REPORTED ALL TOILETS WOULD NOT FLUSH AIRBORNE FOUND CB C11 VACUUM WASTE CONT OPEN ON P91 PANEL SEE PICTURE ATTACHED RESET CB. ALL LAVS FLUSH ON GROUND WITH NO BREAKER TRIP. VACUUM PRESSURE IS GOOD RULING OUT CLOGGED FILTER. POSSIBLE ISSUE WITH BAROMETRIC ALTITUDE SWITCH, S1033, SINCE PROBLEM OCCURS IN AIR. DUE TO EXTENSIVE HISTORY AND DIVERSION, SUGGEST ALSO CHANGING LOGIC CONTROL MODULE AND VACUUM CONTROL RELAY, R581. REF. FIM 38-32 TASK 803 REPLACED R581 VACUUM WASTE CONTROL RELAY REF SSM38-32-12-104 & AMM24-51-11. PARTS USED: 29-2450-3-0006,QTY :1 ADD EMP:U380167 REMOVED AND REPLACED VACUUM BLOWER BAROMETRIC SWITCH IN REFERENCE WITH AMM 38-32-12. REMOVED AND REPLACED LOGIC CONTROL MODULE IN REFERENCE WITH AMM 38-33-03. OPS CHECKS GOOD ON ALL COMPONENTS. AIRCRAFT OK FOR SERVICE. PARTS USED: 99-3832-3-0059,QTY :1 99-3833-9-0002,QTY :1 MFG PN ON - 1742F9 MFG SN ON - 32162 M&E SN ON - 02162 M&E PN ON - 99-3833-9-0002 MFG SN OFF - 33766 MFG PN OFF - 1742F9 ROTABLE PARTS CHG:TT # 1286547 SN OFF 3766 PN OFF 99-3833-9-0002 UNIT, ASSY LOGI OFF 99-3833-9-0002 3766 ON 99-3833-9-0002 2162

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