# SDR 97ZZZX830

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 13, 1997
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N575W](https://openairdocs.org/aircraft/N575W), registered now
- Make and model: Beech C-99
- Registry model: [Beech C-99](https://openairdocs.org/model/beech-c-99) (OpenAirDocs)
- Aircraft serial: U204
- System (JASC): [2913 · Hydraulic Pump (Electric/Engine), Main](https://openairdocs.org/jasc/2913)
- Part: Power Pack
- Part number: 993880029
- Condition: Malfunction
- Location: Lt Mlg
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/97ZZZX830

## Discrepancy

NITROGEN PRE-CHARGE LEAKED PAST ACCUMULATOR PISTON CAUSING PRESSURE BUILD-UP IN RETRACT SIDE OF LANDING GEAR SYSTEM AND COLLAPSE OF LEFT MAIN GEAR WHILE AIRCRAFT WAS BEING TOWED.  SUBMITTER STATED LATER DASH NUMBER HYDRAULIC POWER PACK INCORPORATES A VENT VALVE TO PRECLUDE THIS PRESSURE BUILD-UP IN THE EVENT OF ACCUMULATOR LEAKAGE.  SUBMITTER RECOMMENDS THIS POWER PACK BE RETRO FITTED TO EARLIER AIRCRAFT.  MAIN LANDING GEAR WERE FITTED WITH SAFETY PINS FOR GROUND HANDLING OPERATIONS.

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