AD 91-06-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-100 Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-100B Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-100B SUD Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200B Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200C Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200F Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-300 Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747SP Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747SR Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
Unsafe Condition
Failure of wing leading edge ducts could damage wing panels and/or electrical wiring.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Conduct a penetrant inspection and proof pressure test within specified flight cycles. Repair or replace ducts if cracks or ruptures are found. Replace titanium T-ducts with Inconel T-ducts. Perform duct weld stress relieving as required.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to the accumulation of 5,850 flight cycles or within the next 1,850 flight cycles after the effective date (April 15, 1991), whichever occurs later.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 747 series airplanes, line positions 2 through 707, except Model 747-400 series, certificated in any category.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.