AD 2005-14-12
Unsafe Condition
Propeller mounting bolts, part number B-3339, from LFC Manufacturing Lot No. 12 or Lot No. 56, may fail to properly absorb installation torque or exhibit material surface pitting, leading to improper securing or failure of the propeller mounting bolts, which could result in separation of the propeller from the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Initial visual inspection and torque check of all eight mounting flange bolts when P/N B-3339 bolts from LFC manufacturing Lot No. 12 or Lot No. 56 are present. Repetitive torque checks on all eight mounting flange bolts for affected airplanes, with different intervals depending on the airplane model. Replacement of all P/N B-3339 bolts from LFC Manufacturing Lot No. 12 or Lot No. 56 with bolts that are not from these lots or FAA-approved equivalents. Mandatory replacement of all P/N B-3339 bolts from LFC Manufacturing Lot No. 12 or Lot No. 56 within 12 months after the effective date of the AD.
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Compliance Time
Within 50 hours time-in-service (TIS) or 12 months after the effective date of the AD, whichever occurs first, for the initial inspection and torque check. Repetitive torque checks are required at intervals specified in the AD, depending on the airplane model.
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Affected Aircraft
Hartzell Propeller Inc. models HC-B3TN-2, HC-B3TN-3, HC-B3TN-5, HC-B3MN-3, HC-B4TN-3, HC-B4TN-5, HC-B4MN-5, HC-B4MP-3, HC-B4MP-5, and HC-B5MP-3 propellers installed with propeller mounting bolts, part number B-3339, from LFC Manufacturing Lot No. 12 or Lot No. 56.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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