# SDR 2026F00117

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 29, 2026
- Submitted: June 1, 2026
- Operation: General aviation
- Aircraft: [N253AL](https://openairdocs.org/aircraft/N253AL), registered now
- Make and model: Lear 45LEAR
- Aircraft serial: 361
- System (JASC): [5514 · Horizontal Stabilizer Miscellaneous Structure](https://openairdocs.org/jasc/5514)
- Part: Attach Bolt
- Part number: PN4527401706003
- Condition: Defective
- Location: Zone 300
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026F00117

## Discrepancy

DURING INSTALLATION OF HORIZONTAL STABILIZER ATTACHMENT HARDWARE, MULTIPLE PRIMARY BOLTS P/N 4527401706-003 WERE FOUND TO BE DIMENSIONALLY OUT OF TOLERANCE, PREVENTING PROPER INSTALLATION OF SECONDARY BOLTS.  MEASURED INTERNAL DIAMETER (ID) OF THE PRIMARY BOLTS RANGED FROM APPROXIMATELY 0.3090" TO 0.3095", WHICH IS BELOW THE SPECIFIED DRAWING REQUIREMENT OF 0.3125" TO 0.3135". AS A RESULT, THE SECONDARY BOLTS COULD NOT BE INSTALLED AS INTENDED. ONLY ONE OF THREE RECEIVED PRIMARY BOLTS MET DIMENSIONAL REQUIREMENTS AND WAS USABLE.  ADDITIONAL MEASUREMENTS OF SECONDARY BOLTS SHOWED OUTER DIAMETER (OD) VALUES BETWEEN 0.3115" AND 0.3120", WHICH ARE CONSISTENT WITH EXPECTED DIMENSIONS, CONFIRMING THE DISCREPANCY IS WITH THE PRIMARY BOLT INTERNAL DIAMETER.  MULTIPLE PARTS WERE RECEIVED UNDER THE SAME PROCUREMENT AND DOCUMENTATION (8130 TRACE NUMBER 21081), SUGGESTING A POTENTIAL BATCH OR MANUFACTURING QUALITY ISSUE.  THIS CONDITION RESULTED IN INABILITY TO INSTALL REQUIRED HARDWARE AND REQUIRED REPLACEMENT OF NONCONFORMING PARTS. MANUFACTURER HAS BEEN NOTIFIED AND ADVISED THIS IS A VENDOR QUALITY ESCAPE REQUIRING INVESTIGATION AND CORRECTIVE ACTION.

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