# AD 47-10-30: Fuel Tank Surge Box Flapper Valves

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed 49-46
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 1 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/392C8343E90375418625696D00458DF9.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/47-10-30

## The airworthiness directive

47-10-30 LOCKHEED: (Was Mandatory Note 33 of AD-763-3.) Applies to Model 49 Serials 2047 Up to and Including 2075 and to Serials Prior to 2047 Which Have Had 68092 Surge Box Flapper Valves Replaced by 285750 Valves in Accordance With Lockheed SI-15, Dated June 18, 1946.

Compliance required prior to April 1, 1947.

Replace fuel tank surge box flapper valves, LAC P/N 285750, with new type valve, LAC P/N 285750-600.

(LAC Service Instructions 49/SI-15, revised August 10, 1946, and 49/SI-15A, revised August 3, 1946, or subsequent, cover this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-763](https://openairdocs.org/tcds/A-763): Lockheed Martin Aeronautics Company; names 1 of 6 models: 49-46

## 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: 1 (1 by airframe model, 0 by engine model)
- Makers: Lockheed 1

Models with the most aircraft:

- [Lockheed 49-46](https://openairdocs.org/model/lockheed-49-46): 1 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/47-10-30/models.md
Every aircraft: https://openairdocs.org/ad/47-10-30/aircraft.md

Its text cites no advisory circulars or STCs.

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