# SDR 98ZZZX3232

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 9, 1998
- Submitted: March 26, 2000
- Operation: General aviation
- Filed by: [Rockwell Collins Inc, repair station KI2R953K](https://openairdocs.org/faa-repair-station/KI2R953K/rockwell-collins-inc.md) (OpenAirDocs)
- Aircraft: N85CR
- Make and model: Beech 400A
- Registry model: [Beech 400A](https://openairdocs.org/model/hawker-beechcraft-400a) (OpenAirDocs)
- Aircraft serial: RK22
- System (JASC): [3411 · Pitot/Static System](https://openairdocs.org/jasc/3411)
- Part: Pressure Switch
- Part number: 654A59
- Condition: Leaking
- Location: Pitot System
- 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/98ZZZX3232

## Discrepancy

DURING UNSCHEDULED TEST OF PILOT'S PITOT/STATIC SYSTEM, DETERMINED A SUBSTANTIAL LEAK EXISTED.  THE LEAK WAS TRACED TO THE HORIZONTAL STABILIZER DE-ICE SYSTEM DIFFERENTIAL PRESSURE SWITCH (REF:  DESIGNATION S39B).  THE UNIT IS LEAKING FROM PITOT TO STATIC SIDE INTERNALLY.  RECOMMEND CHECKING PITOT/STATIC SYSTEM FOR LEAKS WHENEVER THERE IS A SIGNIFICANT MISMATCH BETWEEN NR 1 AIRSPEED AND NR 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.