AD 66-07-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 707-100 Long Body | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-100B Long Body | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-100B Short Body | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-200 | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-300 Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-300B Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-300C Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 707-400 Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 720 Series | BOEING Models 707, 720 and 720B Series Airplanes |
| aircraft | The Boeing Company | 720B Series | BOEING Models 707, 720 and 720B Series Airplanes |
Unsafe Condition
Failure of the main landing gear rear axles due to hydrogen embrittlement or stress corrosion.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 800 hours' time in service after the AD's effective date, inspect the main landing gear aft axle for corrosion or inadequate lubrication, remove corrosion, grease the axle, and before further flight. At each aft wheel brake change, repeat inspection. Inspect chrome-plated axles for cracks, remove chrome plate and rework defects if found. Do not chrome plate axles after the AD's effective date.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 800 hours' time in service after the effective date of this AD, unless already accomplished, and thereafter at each aft wheel brake change.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Models 707, 720, and 720B Series airplanes except those with axles modified per Boeing Service Bulletin 2028, 2221, 2246, or specific models like 707-121B, 707-139B, 707-131B, 707-300B, 707-300C Series, or modified with 4 Brake Rod configuration.
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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