SDR 0100226625

Service difficulty report · Controller · Boeing 747251B

Difficulty date: January 18, 2001
Submitted: January 26, 2001
Operation: Air carrier
Aircraft: N625US
Make and model: Boeing 747251B
Aircraft serial: 21707
Aircraft time: 81,965 hours, 13,958 cycles
System (JASC): 2131 · Cabin Pressure Controller
Part: Controller
Condition: Failed
Location: Cabin Pressure
Stage of operation: CL
How discovered: O
Nature of condition: J
Precautionary procedure: B, A

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

What was found

DURING CLIMB AT 24,000 FEET, THE PRESSURIZATION AUTO FAIL LIGHT ILLUMINATED ACCOMPANIED WITH THE NR 2 PACK TRIPPING AND THE PRESSURE RELIEF LIGHT ILLUMINATING. PERFORMED AN EMERGENCY DESCENT TO 10,000 FEET AND CABIN WAS CONTROLLED MANUALLY AT 14,000 FEET. AIRCRAFT RETURNED TO NRT AND LANDED WITHOUT INCIDENT. REPLACED THE CABIN PRESSURE CONTROLLER, CONTROL PANEL, AND PRESSURE RELIEF VALVE. OPERATIONAL CHECK GOOD.