# AD 47-27-01: Wing inspection (tank area)

- Type: Airworthiness directive
- Status: Current
- Products: Waco Aircraft Company, The UKS-7, VKS-7 (Army UC-72D) and VKS-7F
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 14 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/AABDB3AE99E8C0FC86256A4D004ADCE7.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-27-01

## The airworthiness directive

47-27-01 WACO: (Was Mandatory Note 4 of AD-648-1.) Applies to Models UKS-7, VKS-7, VKS-7F Aircraft. Compliance required not later than next periodic inspection. Inspect tank area in wings for damage to plywood tank support and wing spars caused by collection of moisture in the boxed area of the fuel tank. 1. Remove the left and right fuel tanks and inspect the condition of the plywood tank support and the front and rear spars. 2. If the plywood supports are found to be in poor condition they should be replaced using new plywood. 3. If the spars have been affected by the accumulated moisture, repairs should be made in accordance with FAA requirements or in extreme cases the spar should be replaced. 4. In order to provide drainage of the tank compartment three holes 3/16 inch in diameter should be drilled through the plywood support at the extreme rear of the support as close to the rear spar as possible without damaging the spar. These drain holes should, of course, extend through the fabric covering. 5. The drain holes should be drilled in all tank compartments at the time the fuel tanks are removed for this inspection. (The above inspection and recommended remedial measures also covered by Waco Aircraft Co. Service Letter No. 3.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS ATC 648](https://openairdocs.org/tcds/ATC%20648): The Waco Aircraft Company; names 3 of 3 models: UKS-7, VKS-7 (Army UC-72D), VKS-7F

## 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: 14 (14 by airframe model, 0 by engine model)
- Makers: Waco 14

Models with the most aircraft:

- [Waco VKS-7F](https://openairdocs.org/model/waco-vks-7f): 7 aircraft (airframe model)
- [Waco VKS-7](https://openairdocs.org/model/waco-vks-7): 5 aircraft (airframe model)
- [Waco UKS-7](https://openairdocs.org/model/waco-uks-7): 2 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/47-27-01/models.md
Every aircraft: https://openairdocs.org/ad/47-27-01/aircraft.md

Its text cites no advisory circulars or STCs.

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