AD 99-21-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | DC-9-81 (MD-81) | Airworthiness Directives; McDonnell Douglas Model DC-9-81, -82, -83, and -87 Series Airplanes (MD-81, -82, -83, and -87), and Model MD-88 Airplanes |
| aircraft | The Boeing Company | DC-9-82 (MD-82) | Airworthiness Directives; McDonnell Douglas Model DC-9-81, -82, -83, and -87 Series Airplanes (MD-81, -82, -83, and -87), and Model MD-88 Airplanes |
| aircraft | The Boeing Company | DC-9-83 (MD-83) | Airworthiness Directives; McDonnell Douglas Model DC-9-81, -82, -83, and -87 Series Airplanes (MD-81, -82, -83, and -87), and Model MD-88 Airplanes |
| aircraft | The Boeing Company | DC-9-87 (MD-87) | Airworthiness Directives; McDonnell Douglas Model DC-9-81, -82, -83, and -87 Series Airplanes (MD-81, -82, -83, and -87), and Model MD-88 Airplanes |
| aircraft | The Boeing Company | MD-88 | Airworthiness Directives; McDonnell Douglas Model DC-9-81, -82, -83, and -87 Series Airplanes (MD-81, -82, -83, and -87), and Model MD-88 Airplanes |
Unsafe Condition
Cracking of the actuator cylinder support brackets of the slat drive mechanism assembly outside the original inspection area could cause inadvertent slat retraction in flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Perform visual and/or eddy current inspections of the actuator cylinder support brackets per specified intervals and service bulletins. Replace any cracked brackets with new parts prior to further flight. Repeat inspections at intervals not exceeding 3,000 landings until terminating action is taken.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Varies based on inspection type and prior compliance: within 30 days of AD effective date or 10,000 landings, with subsequent intervals up to 3,000 landings.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
McDonnell Douglas Model DC-9-81, -82, -83, -87 (MD-81, -82, -83, -87), and MD-88 airplanes, all serial numbers.
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.