AD 2021-17-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | Company | Airworthiness Directives; The Boeing Company Airplanes |
Unsafe Condition
cracks found in the front spar shear tie and at the intercostal lug fitting at certain locations
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
repetitive detailed and surface high frequency eddy current (HFEC) inspections of the front spar shear tie and intercostal lug fitting at certain locations for any cracking, and applicable on-condition actions
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 flight hours
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
all The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, 747SR, and 747SP airplanes
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.