SDR 2026F00117

Service difficulty report · Attach Bolt · Lear 45LEAR

Difficulty date
May 29, 2026
Submitted
June 1, 2026
Operation
General aviation
Aircraft
N253AL
Make and model
Lear 45LEAR
Aircraft serial
361
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

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

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.