# AD 64-09-03: Aileron Mass Balance Weight Arm

- Type: Airworthiness directive
- Status: Historical
- Products: Viking Air DHC-2 Mk.I, DHC-2 Mk.II and DHC-2 Mk.III
- Effective: May 22, 1964
- Published: April 22, 1964
- Issued: April 15, 1964
- Superseded by: [AD 2023-19-06](https://openairdocs.org/ad/2023-19-06)
- Product type: Aircraft, Small airplane
- Registered aircraft: 140 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/52210A58A3890BE486256A34006D465A.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/64-09-03

## The airworthiness directive

64-09-03 de HAVILLAND: Amdt. 718 Part 507 Federal Register April 22, 1964. Applies to All Model DHC-2 "Beaver" Aircraft.

Compliance required as indicated.

As a result of cracks and corrosion found on the aileron mass balance weight arm C2WA151 and C2WA152 or C2WA127 and C2WA128, accomplish the following inspection within 25 hours' time in service after the effective date of this AD, unless already accomplished within the last 475 hours' time in service, and thereafter within 500 hours' time in service from the last inspection.

  (a) Inspect the aileron mass balance weight arm on each aileron for cracks and corrosion, particularly around welds, using a dye penetrant and a 10-power magnifying glass, or an FAA-approved equivalent inspection. Prior to inspection, remove all paint (using a paint solvent which will not have a deleterious effect upon the base metal), grease and dirt from all surfaces involved.

  (b) If cracks or corrosion are found, replace the part witha new part of the same part number, or an equivalent, approved by the Chief, Engineering and manufacturing Branch, FAA Eastern Region, or make a repair approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. This is to be accomplished before further flight, except that one flight may be made in accordance with the provisions of CAR 1.76 for the purpose of obtaining these repairs.

(de Havilland Engineering Bulletin Series "B", No. 17, dated November 20, 1959, available from de Havilland Aircraft of Canada, Ltd., Toronto, Canada, covers this same subject.)

This directive effective May 22, 1964.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-806](https://openairdocs.org/tcds/A-806): De Havilland Aircraft of Canada Limited; names 3 of 3 models: DHC-2 Mk.II, DHC-2 Mk.III, DHC-2 Mk.I

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 140 (140 by airframe model, 0 by engine model)
- Makers: Dehavilland 135, Dehavilland Acft Of Canada 3, Dehavilland-Shawano 2

Models with the most aircraft:

- [Dehavilland DHC-2 MK. I(L20A)](https://openairdocs.org/model/dehavilland-dhc-2-mk-i-l20a): 91 aircraft (airframe model)
- [Dehavilland DHC 2 MK III](https://openairdocs.org/model/dehavilland-dhc-2-mk-iii): 24 aircraft (airframe model)
- [Dehavilland DHC-2 MK.I](https://openairdocs.org/model/dehavilland-dhc-2-mk-i): 20 aircraft (airframe model)
- [Dehavilland Acft Of Canada DHC-2 MK I](https://openairdocs.org/model/dehavilland-acft-of-canada-dhc-2-mk-i): 3 aircraft (airframe model)
- [Dehavilland-Shawano DHC-2 MK.I](https://openairdocs.org/model/dehavilland-shawano-dhc-2-mk-i): 2 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/64-09-03/models.md
Every aircraft: https://openairdocs.org/ad/64-09-03/aircraft.md

## Related documents

- [AD 2023-19-06](https://openairdocs.org/ad/2023-19-06): Airframe · Viking Air DHC-2 Mk.II, DHC-2 Mk.I and DHC-2 Mk.III. Effective Nov 6, 2023. Supersedes this AD

Its text cites no advisory circulars or STCs.

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