# SDR 98ZZZX355

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 21, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- System (JASC): [3416 · Altimeter, Barometric/Encoder](https://openairdocs.org/jasc/3416)
- Part: Altimeter
- Part number: 5035P2
- Condition: Binding
- Location: Encoder Mesh
- Component: Unitedinst
- 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/98ZZZX355

## Discrepancy

WHEN RECEIVED, THIS ALTIMETER WAS STUCK AT 7,000 FEET.  DISASSEMBLY REVEALED 2 CONDITIONS THAT CAUSED THE HANG-UP PROBLEM.  THE ENCODER MESH WAS BINDING AND THERE WAS NO END SHAKE IN THE ROCKING SHAFT.  THE MOUNTING CONFIGURATION FOR THE ENCODER IS INADEQUATE FOR SUPPORTING THE GEAR MESH ACCURATELY.  THE MECHANISM CASTING IS UNSTABLE WHICH ALLOWS THE END SHAKES ON THE CRITICAL SHAFTS TO CLOSE IN.  NOTE:  THIS WAS A FACTORY SEALED ALTIMETER.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.