AD 91-20-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 737-300 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
| aircraft | The Boeing Company | 737-400 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
| aircraft | The Boeing Company | 737-500 Series | Airworthiness Directives; BOEING Model 737-300, -400, and -500 Series Airplanes |
Unsafe Condition
Uncommanded stabilizer movement in the static position due to potential failure of the stabilizer trim jackscrew actuator and auxiliary brake assembly.
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Required Actions
Remove the existing stabilizer trim jackscrew actuator and replace it with a modified stabilizer trim assembly having a redesigned auxiliary brake assembly per Boeing Service Bulletin 737-27-1161. An alternative method of compliance may be used if approved by the FAA Manager, Seattle Aircraft Certification Office.
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Compliance Time
within 36 months after the effective date of this AD
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Affected Aircraft
Boeing Model 737-300, -400, and -500 series airplanes listed in Boeing Service Bulletin 737-27-1161, dated November 1, 1990.
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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