# AD 64-20-01: Pitch Change Blocks

- Type: Airworthiness directive
- Status: Current
- Products: Hartzell Propeller HC-C2Y and HC-E2Y
- Effective: August 28, 1964
- Superseded by: Nothing supersedes this AD
- Product type: Propeller
- Amendment: 39-803
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/56B338559E68D24886256965005F1EF5.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/64-20-01

## The airworthiness directive

64-20-01 HARTZELL: Amdt. 803 Part 507 Federal Register August 28, 1964. Applies to Models HC-C2YK-1/7666-2 Serial Numbers AW-1 to AW-603 and HC-E2YL-2B/7663-4 Propellers Serial Numbers BG-1 to BG-777.

Compliance required as indicated.

There have been incidents of failure of the plastic pitch change blocks in Hartzell HC- E2YL-2B and HC-C2YK-1 propellers which resulted in severe roughness or vibration in flight. To correct this condition, accomplish the following:

  (a) Inspect propeller blades for pitch change movement and replace plastic pitch change blocks as necessary in accordance with Hartzell Service Bulletin No. 86 revised June 17, 1964, within 10 hours' time in service after the effective date of this AD unless already accomplished within the last 10 hours' time in service, and thereafter within every 10 hours' time in service from the last inspection.

  (b) When the modification specified in Hartzell Service Bulletin No. 86, revised June 17, 1964, has beenaccomplished, the repetitive inspections specified in paragraph (a) may be discontinued.

(Hartzell Service Bulletin No. 86, revised June 17, 1964, covers this same subject.)

This directive effective August 28, 1964.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS P-920](https://openairdocs.org/tcds/P-920): Hartzell Propeller LLC; names 1 of 4 models: HC-C2Y
- [TCDS P9EA](https://openairdocs.org/tcds/P9EA): Hartzell Propeller LLC; names 1 of 3 models: HC-E2Y

## 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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