# AD 66-23-02: Corrosion Pits

- Type: Airworthiness directive
- Status: Current
- Products: Sensenich Propeller Manufacturing Fixed-Pitch Metal Propellers
- Effective: May 16, 1967
- Superseded by: Nothing supersedes this AD
- Product type: Propeller
- Amendment: 39-289
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/488D6A0BE3672E0286256966006CA66A.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/66-23-02

## The airworthiness directive

66-23-02 SENSENICH: Amdt. 39-289 Part 39 Federal Register September 22, 1966. Applies to All Fixed-Pitch Metal Propeller Models with Water-Soluble Mid-Blade Decals.

Compliance required within the next 20 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent further mid-blade propeller failures resulting from corrosion pits that initiate fatigue cracks under the water-soluble mid-blade decal, accomplish the following:

  (a) Soak water-soluble mid-blade decals (Sensenich Propeller Bulletin No. R-12 describes decals) with paint remover and rub off with a rag. (Scraping or sanding of decals may inadvertently obscure evidence of possible corrosion.)

  (b) Apply dye penetrant to the mid-blade area and inspect for corrosion and cracks with a glass of at least three power.

  (c) Remove corrosive pits 0.015 inch deep or less by sanding with a 220 grit wet or dry abrasive paper and polishing with a paper of 320 grit or finer.(d) Clean area thoroughly and reinspect in accordance with (b) to insure that the removal of all corrosive pits has been accomplished. Clean and spray repaired area with a clear lacquer.

  (e) Replace before further flight any propeller having corrosive pits 0.015 inch deep or greater or having cracks with a propeller of the same model number that has been inspected and repaired as necessary in accordance with this AD.

(Sensenich Propeller Bulletins Nos. R-11, dated March 1, 1966; R-12 dated August 1, 1966, and R-12A dated February 6, 1967, pertain to this subject.)

This supersedes AD 66-11-03.

This directive becomes effective October 1, 1966.

Revised May 16, 1967.

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

## NTSB investigations that cite this AD (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB ATL86FA082](https://openairdocs.org/ntsb/ATL86FA082), Feb 27, 1986: Beech A23 (N3536R), Russellville, AL, substantial damage, 2 fatal

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