# SDR DJFA2004041

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 16, 2004
- Submitted: December 20, 2004
- Operation: Air carrier
- Aircraft: N753TA
- Make and model: Beech 400A
- Registry model: [Beech 400A](https://openairdocs.org/model/hawker-beechcraft-400a) (OpenAirDocs)
- Aircraft serial: RK230
- Aircraft time: 4,995 hours, 4,077 cycles
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: Duct
- Condition: Leaking
- Location: Bleed Air Sys
- Stage of operation: CL
- How discovered: O
- Nature of condition: B
- Precautionary procedure: G
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DJFA2004041

## Discrepancy

CLIMBING TO 10,000 FT, LT BLEED AIR DUCT FAIL ANNUNCIATOR HAD ILLUMINATED.  ENG THRUST REDUCED, AND CABIN PRESSURIZATION SOURCE TURNED OFF.  TWO MINS LATER COCKPIT & CABIN HAD FILLED WITH SMOKE FOLLOWED BY EMERGENCY PRESSURIZATION VALVE OPENING.  CREW DONNED OXYGEN MASKS & GOGGLES AS SMOKE HAD BECOME FAIRLY THICK.  AN EMERGENCY WAS DECLARED & AIRCRAFT MADE AN UNEVENTFUL LANDING.  MX FOUND A Y-DUCT ON LEFT SIDE TO BE MISALIGNED AND LEAKING.  A NEW SEAL WAS INSTALLED ON THE OUTBOARD DUCT AT THE TOP OF THE FUSELAGE ABOVE THE PYLONS.  THE EMERGENCY PRESSURIZATION VALVE WAS FOUND TO BE STUCK IN THE OPEN POSITION.  A NEW VALVE WAS INSTALLED.  OPERATIONAL CHECKS WERE NORMAL.  AIRCRAFT WAS RETURNED TO SERVICE.

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