47-27-01: Wing inspection (tank area)
FAA order 47-27-01 is an airworthiness directive. The FAA's subject line: Wing inspection (tank area). It names Waco VKS-7: about 12 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: airframe structure.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Waco Aircraft Company, The
- Models
- UKS-7, VKS-7 (Army UC-72D), VKS-7F
- On this site
- Waco VKS-7 12 registered
Dates and paperwork
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (1,261 characters)
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.)
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 5, 2026. Connections as data: /graph/directive/47-27-01.json · aircraft systems.