# SDR 99ZZZX3590

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 11, 1999
- Submitted: March 26, 2000
- Operation: General aviation
- Make and model: Cessna 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (OpenAirDocs)
- System (JASC): [5610 · Flight Compartment Windows](https://openairdocs.org/jasc/5610)
- Part: Windscreen
- Condition: Failed
- Location: Cockpit
- Stage of operation: CR
- Nature of condition: F
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99ZZZX3590

## Discrepancy

AIRCRAFT WAS AT 17,000 FEET, WHEN IT EXPERIENCED A CATASTROPHIC FAILURE OF THE PILOT'S WINDSCREEN CAUSING INSTANT DEPRESSURIZATION OF CABIN.  CAUSE OF THIS FAILURE AT THIS TIME IS UNKNOWN.  A POSSIBILITY IS THAT THE WINDSCREENS WERE REWORKED TO REMOVE SCRATCHES AND THIS WEAKENED THEM.

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