AD 49-11-01

Airworthiness directive · Carter Fuel Pump Rework · Sierra Hotel Aero Navion (Army L-17A) and Navion A (Army L-17B and L-17C)

Models
Navion (Army L-17A), Navion A (Army L-17B and L-17C)
Data sheet
TCDSA-782
Registered aircraft
633 matched by model
Product
Aircraft · Small airplane

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.

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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 TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft · 633

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

By aircraft maker
  • Ryan285 aircraft
  • North American249 aircraft
  • Navion99 aircraft
By year built
19461963
Registered aircraft by year built: 485 aircraft
1946103
1947133
1948143
194978
195021
19511
19531
19561
19582
19591
19631

148 with no year recorded

By model

Aircraft

See all 633 aircraft