AD 86-12-04
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
Cracking in the horizontal stabilizer center section rear spar upper chord near each beam gusset plate.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Eddy current inspect the horizontal stabilizer center section rear spar upper chord for cracks in the areas of each beam gusset plate prior to specified landing counts. Repeat inspections at intervals not exceeding 4,500 landings. Repair or replace the chord if cracks are found, following specified service bulletin instructions.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to the accumulation of 50,000 landings; or prior to 50,000 landings after chord replacement; or prior to 35,000 landings after modification per SB 737-55-1034 Part II; or within 500 landings after the AD's effective date (June 30, 1986); whichever occurs latest, unless accomplished within the last 4,000 landings.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 737 series airplanes certificated in any category, as listed in Boeing Service Bulletin 737-55-1034 dated April 12, 1985.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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