# AD 64-28-01: Hub Spiders

- Type: Airworthiness directive
- Status: Current
- Products: Hartzell Propeller HC-12X20-1, HC-12X20-2, HC-12X20-3, HC-12X20-5 and HC-12X20-7
- Effective: June 18, 1965
- Superseded by: Nothing supersedes this AD
- Product type: Propeller
- Amendment: 39-14
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8C08DF153CF668A386256CE90046923C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/64-28-01

## The airworthiness directive

64-28-01 HARTZELL: Amdt. 39-14 Part 39 Federal Register December 16, 1964. Applies to Models HC-12X20-1, -2, -3, -5, and -7B Propellers Equipped with C-49-2B and C-49-2C Hub Spiders Having Serial Numbers 4220 through 5400 Installed on Downer (Republic) RC-3; Navion, Navion A; and Grumman G-44 Series Aircraft.

Compliance required as indicated.

As a result of loss of propeller blade due to failure of a hub spider, accomplish the following:

  (a) Visually inspect propeller hub spiders for cracks in accordance with Hartzell Service Bulletin No. 32 amended August 11, 1964, within 10 hours' time in service after the effective date of this AD, and at intervals thereafter not to exceed 25 hours' time in service from the last inspection until modification in accordance with Hartzell Service Bulletin No. 32 amended August 11, 1964, is accomplished. Replace cracked parts before further flight

  (b) Replace propeller hub spiders having accumulated less than 400 hours' time in service since new or last overhaul in accordance with Hartzell Service Bulletin No. 32 amended August 11, 1964, prior to the accumulation of 500 hours' total time in service since new or last overhaul.

  (c) Replace propeller hub spiders having accumulated 400 or more hours' time in service since new or last overhaul in accordance with Hartzell Service Bulletin No. 32 amended August 11, 1964, prior to the accumulation of 100 hours' time in service after the effective date of this AD.

(Hartzell Service Bulletin No. 32 dated March 9, 1955, amended August 11, 1964, covers this subject.)

This directive effective January 15, 1965

Revised April 8, 1965.

Revised June 18, 1965.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS P-845](https://openairdocs.org/tcds/P-845): Hartzell Propeller Inc.; names 5 of 9 models: HC-12X20-7, HC-12X20-5, HC-12X20-3, HC-12X20-2, HC-12X20-1

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

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