AD 86-18-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 737-100 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-200 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-200C Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-300 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-400 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-500 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-600 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-700 Series | BOEING Model 737 Series Airplanes |
| aircraft | The Boeing Company | 737-800 Series | BOEING Model 737 Series Airplanes |
Unsafe Condition
Self-locking nuts (P/N BACN10JC12CM and P/N BACN10JC12CD) installed at the Body Buttock Line (BBL) 70.85 wing-to-body splice plate, thrust reverser secondary deactivation pin, and vertical fin front spar to closure rib attachments have insufficient self-locking torque characteristics.
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Required Actions
Within 18 months after the effective date, check the self-locking nuts for proper self-locking torque per Boeing Service Letter 737-SL-27-38. Replace any nut not meeting torque criteria prior to further flight. Alternate compliance may be approved by the FAA Manager, Seattle Aircraft Certification Office.
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Compliance Time
Within the next 18 months after the effective date of this AD
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Affected Aircraft
Boeing Model 737 series airplanes, line numbers 930 and above, listed in Boeing Service Letter 737-SL-27-38 dated January 16, 1986.
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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