SDR SWAA096419

Service difficulty report · Check Valve · Boeing 7373H4

Difficulty date: October 1, 2009
Submitted: October 8, 2009
Operation: Air carrier
Aircraft: N323SW
Make and model: Boeing 7373H4
Aircraft serial: 23344
Aircraft time: 72,992 hours, 65,992 cycles
System (JASC): 4950 · APU Bleed Air System
Part: Check Valve
Part number: 12355814
Part serial: 4163
Condition: Faulty
Location: Apu Bleed Air
Stage of operation: NR
How discovered: O
Nature of condition: O
Precautionary procedure: A

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

What was found

DECLARED EMERGENCY, AT 36,000 FT AIRCRAFT SLOWLY LOST PRESSURIZATION. NO LIGHT ON PRESS PANEL, OUTFLOW VALVE WAS FULLY CLOSED. PRESSURIZATION WAS REGAINED AT APPROX 14,000 FT IN DESCENT. NO POPS OR BANGS WERE NOTED. REMOVED AND REPLACED APU BLEED AIR CHECK VALVE PER MM.

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