# AD 46-23-05: Horizontal Stabilizer Drain Holes

- Type: Airworthiness directive
- Status: Current
- Products: Noorduyn Army UC-64, Army UC-64A and Army UC-64B
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CAA27FBF42D0E96786256A450067ECCC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/46-23-05

## The airworthiness directive

46-23-05 NOORDUYN: (Was Mandatory Note 1 of AD-2-578-1.) Applies to Army UC- 64, -64A, and -64B Aircraft. Required at next periodic inspection. Inspect the trailing edge of the horizontal stabilizer to determine whether or not drain holes are present in the metal trailing edge cover. If the holes are not present, it will be necessary to remove enough fabric to permit inspection of the ribs. Defective or deteriorated wood must be replaced and drain holes, approximately 1/16-inch diameter, spaced to drain all pockets must be drilled.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-2-578](https://openairdocs.org/tcds/A-2-578): Noorduyn Aviation Ltd.; names 3 of 7 models: Army UC-64B, Army UC-64, Army UC-64A

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.