# AD 47-21-04: Fuel Scupper Drain Line

- Type: Airworthiness directive
- Status: Current
- Products: Sierra Hotel Aero Navion (Army L-17A)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 373 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1D5155BFAC995C9086256A56006E0D81.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-21-04

## The airworthiness directive

47-21-04 NAVION: (Was Mandatory Note 3 of AD-782-3.) Applies to Serial Numbers NAV-4-2 Through 21, 24 Through 29, 32, 35, 36, 40, 42 Through 47, 57, 192, 199, 251.

To be accomplished not later than August 1, 1947.

The original fuel filler scupper will collect spilled gasoline since no drain line is provided. In addition, the thickness of material is insufficient to prevent damaging by the filler hose nozzle. To eliminate these conditions, a redesigned scupper with drain line is to be installed per NAA Drawing 145-89010.

(NAA Field Service Bulletin No. 2 covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-782](https://openairdocs.org/tcds/A-782): Sierra Hotel Aero Inc.; names 1 of 8 models: Navion (Army L-17A)

## 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: 373 (373 by airframe model, 0 by engine model)
- Makers: North American 203, Ryan 170

Models with the most aircraft:

- [North American NAVION](https://openairdocs.org/model/north-american-navion): 203 aircraft (airframe model)
- [Ryan NAVION](https://openairdocs.org/model/ryan-navion): 170 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/47-21-04/models.md
Every aircraft: https://openairdocs.org/ad/47-21-04/aircraft.md

Its text cites no advisory circulars or STCs.

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