AD 67-20-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Pacific Propeller, Inc. | A6441FN-606 | ALLISON - AERO PRODUCTS Models A6441FN-606 and A6441FN-606A Propellers |
Unsafe Condition
Retention bolts may fail, leading to serious overspeeds and reduced effectiveness of the propeller pitch lock under remote combinations of critical component failures.
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Required Actions
Install Part No. 6859637 restrictor in the increase pitch port of each hub island and replace the eight master gear retention bolts with P/N 6859881 bolts. Actions must be accomplished as outlined in specified Allison documents.
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Compliance Time
On or before November 1, 1967
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Affected Aircraft
Pacific Propeller, Inc. Models A6441FN-606 and A6441FN-606A Propellers
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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