# AD 49-11-01: Carter Fuel Pump Rework

- Type: Airworthiness directive
- Status: Current
- Products: Sierra Hotel Aero Navion (Army L-17A) and Navion A (Army L-17B and L-17C)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 633 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/828EDFBFE4BD594686256A56006F0A8C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/49-11-01

## The airworthiness directive

49-11-01 NAVION: Applies to Airplanes Equipped With Carter Fuel Pumps Continental P/N 530509 (Carter M687-S and M688-S) or Continental P/N 50375.

To be accomplished as soon as possible but not later than April 15, 1949.

Due to Carter fuel pump lower diaphragm failures, caused by diaphragm deterioration due to excessive pump temperatures when pumps are run dry, the two Carter pumps should be connected in series to insure that fuel will be continuously flowing both pumps and that the pumps will not overheat.

It is therefore required that all parallel Carter pump fuel systems be converted to the series pump arrangement, or, as an alternative, that either an approved Ryan fuel system incorporating an Adel electric booster pump or an equivalent approved fuel system be installed.

Ryan Navion Field Service Bulletin No. 7 also covers this subject and describes means for connecting the fuel pumps in series. In addition, the daily inspections for looseness of the pump lower bowl, which are specified in section II of Ryan's Bulletin No. 7, should be continued.

This supersedes AD 48-40-01.

## 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 2 of 8 models: Navion (Army L-17A), Navion A (Army L-17B and L-17C)

## 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: 633 (633 by airframe model, 0 by engine model)
- Makers: Ryan 285, North American 249, Navion 99

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)
- [Ryan NAVION A](https://openairdocs.org/model/ryan-navion-a): 115 aircraft (airframe model)
- [Navion NAVION A](https://openairdocs.org/model/navion-navion-a): 99 aircraft (airframe model)
- [North American NAVION A](https://openairdocs.org/model/north-american-navion-a): 46 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/49-11-01/models.md
Every aircraft: https://openairdocs.org/ad/49-11-01/aircraft.md

Its text cites no advisory circulars or STCs.

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