SDR UPS01435014

Service difficulty report · Controller · Boeing 747283B

Difficulty date: February 16, 2001
Submitted: February 19, 2001
Operation: Air carrier
Aircraft: N523UP
Make and model: Boeing 747283B
Aircraft serial: 22381
System (JASC): 2131 · Cabin Pressure Controller
Part: Controller
Condition: Inoperative
Location: Pressure Sys
Stage of operation: CL
How discovered: O
Nature of condition: J
Precautionary procedure: J, A

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

What was found

INSPECTION TYPE:N/A, ON CLIMBOUT LOST PRESSURIZATION AND WAS UNABLE TO CONTROL PRESSURIZATION. IN AUTO PRESS WAS UNCONTROLABLE AT 8.4PSI WENT TO MANUAL AND COULD NOT GAIN CONTROL OF PRESS. PRESS LIGHT CAME ON. DUMPED FUEL AND RTB. INSPECTED FUSELAGE EXTERIOR, NO DEFECT NOTED. SUSPECT AUTO CABIN PRESS CONTROLLER WAS INOP, MANUAL CONTROL IS NORMAL. ITEM TRANSFERRED TO MEL 21-22-1. SECURED PRESS RELIEF VALVE PER MM 21-32-01. OK FOR SERVICE.