# SDR WRNA200700010

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 15, 2007
- Submitted: February 19, 2007
- Operation: Air carrier
- Aircraft: [N526UP](https://openairdocs.org/aircraft/N526UP), registered now
- Make and model: Boeing 747 212B
- Registry model: [Boeing 747 212B](https://openairdocs.org/model/boeing-747-212b) (OpenAirDocs)
- Aircraft serial: 21937
- Aircraft time: 89,777 hours, 16,916 cycles
- System (JASC): [5510 · Horizontal Stabilizer Structure](https://openairdocs.org/jasc/5510)
- Part: Ball Screw
- Condition: Failed
- Location: Horiz Stab
- Stage of operation: IN
- How discovered: C
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/WRNA200700010

## Discrepancy

DURING C-CHECK, HORIZONTAL STABILIZER BALL SCREW AND BALL NUT FAILED FREE PLAY CHECK. REMOVED STABILIZER DRIVE MECHANISM, CHECKED WEAR OF PINS AND FITTINGS, FOUND IN TOLERANCE IAW 747 MM 27-41-06. REINSTALLED DRIVE MECHANISM PER 747 MM 27-41-06 AND PERFORMED BALL NUT TO BALL SCREW FEE PLAY TEST IAW SB 747 27A2396, FOUND FREE PLAY LESS THAN 0.012, WITH-IN LIMITS, ACCOMPLISHED LUBRICATION OF BALL NUT AND JACKSCREW IAW 747 MM 12-21-19 AND S/B 747-272396

---
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.