AD 74-14-01

final rule
Data completeness: 60%

HARTZELL PROPELLERS Models T10173H()+(), T10176H()+(), T10178H()-(), and ()T10282H()+(), HC-B3TN-2( ), HC- B3TN-3( ), HC-B3TN-5( ), HC-B3TN-7( ), HC-B3TF-7( ), HC-B4TN-3( ) and HC-B4TN-5( ) Propellers

AD Number
74-14-01
Status
final_rule
Effective Date
Product Category
propeller
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Hartzell Propeller, Inc. HC-B3T HARTZELL PROPELLERS Models T10173H()+(), T10176H()+(), T10178H()-(), and ()T10282H()+(), HC-B3TN-2( ), HC- B3TN-3( ), HC-B3TN-5( ), HC-B3TN-7( ), HC-B3TF-7( ), HC-B4TN-3( ) and HC-B4TN-5( ) Propellers
aircraft Hartzell Propeller, Inc. HC-B4TN-3 HARTZELL PROPELLERS Models T10173H()+(), T10176H()+(), T10178H()-(), and ()T10282H()+(), HC-B3TN-2( ), HC- B3TN-3( ), HC-B3TN-5( ), HC-B3TN-7( ), HC-B3TF-7( ), HC-B4TN-3( ) and HC-B4TN-5( ) Propellers
aircraft Hartzell Propeller, Inc. HC-B4TN-5 HARTZELL PROPELLERS Models T10173H()+(), T10176H()+(), T10178H()-(), and ()T10282H()+(), HC-B3TN-2( ), HC- B3TN-3( ), HC-B3TN-5( ), HC-B3TN-7( ), HC-B3TF-7( ), HC-B4TN-3( ) and HC-B4TN-5( ) Propellers

Unsafe Condition

Blade cracks and defects in Hartzell propellers could lead to blade failures.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect blades for cracks or defects per Hartzell Bulletin No. 105 or equivalent procedure. Replace cracked or defective blades before further flight with compliant blades or those inspected and found satisfactory.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within the next 50 hours time in service for propellers with less than 950 hours, prior to 1000 hours in service for those between 950-1000 hours, or as adjusted by FAA approval.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Hartzell Propeller, Inc. models HC-B3TN-2, HC-B3TN-3, HC-B3TN-5, HC-B3TN-7, HC-B3TF-7, HC-B4TN-3, HC-B4TN-5 propellers with serial numbers below specified thresholds (e.g., HC-B3TN-2 S/N AG-275 and below).

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

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