AD 72-11-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | 411 | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 411A | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421 | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421A | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421B | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
| aircraft | Cessna Aircraft Company | 421C | Airworthiness Directives; CESSNA Model 411 and 421 Series Airplanes |
Unsafe Condition
Auxiliary fuel cell leakage could result in possible fire and explosion hazards from fuel vapor ignition.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect the lower wing surfaces near auxiliary fuel cells for stains/leakage. Replace leaking cells with improved cells per Cessna Service Letter ME72-8. For Model 411 (411-0001-0200), daily inspections until January 1, 1973, then mandatory replacement. For Model 411 (411-0201-0300) and Model 421 (421-0001-421B0048), inspections every 100 flight hours until improved cells are installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 10 hours' time in service after the effective date of this AD, and thereafter as specified (daily or every 100 flight hours).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Cessna Model 411 (Serial Numbers 411-0001 thru 411-0300) and Model 421 (Serial Numbers 421-0001 thru 421B0048) airplanes.
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.