AD 72-02-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | 411 | Airworthiness Directives; CESSNA Models 411, 411A, 421, 421A and 421B Airplanes |
| aircraft | Cessna Aircraft Company | 411A | Airworthiness Directives; CESSNA Models 411, 411A, 421, 421A and 421B Airplanes |
| aircraft | Cessna Aircraft Company | 421 | Airworthiness Directives; CESSNA Models 411, 411A, 421, 421A and 421B Airplanes |
| aircraft | Cessna Aircraft Company | 421A | Airworthiness Directives; CESSNA Models 411, 411A, 421, 421A and 421B Airplanes |
| aircraft | Cessna Aircraft Company | 421B | Airworthiness Directives; CESSNA Models 411, 411A, 421, 421A and 421B Airplanes |
Unsafe Condition
Propeller separation in flight as a result of rough engine operation.
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Required Actions
Check torque on propeller attachment nuts using specified torque values and adapters. Perform detailed inspection if nuts are loose. Modify engine tachometer with yellow arcs, install operational placards, replace Airplane Flight Manual pages with specified revisions, and obtain approval for equivalent methods if needed.
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Compliance Time
within the next 50 hours' time in service after the effective date of this AD
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Affected Aircraft
Cessna Models 411, 411A, 421, 421A, and 421B (up to and including Serial Number 421B0147)
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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