51-14-01 BEECH: Applies to All Models 35 and A35 Aircraft Equipped With Unmodified Adel 20653 Electric Fuel Pump Installation.
Compliance was required as soon as possible, but in any event, not later than April 1, 1949.
To prevent the possibility of air leakage into the airplane's fuel system through a leaking shaft seal of the unmodified 20653 pump, this pump and associated installation components are to be removed from the airplane. Aircraft equipped with a modified fuel booster pump installation, which consists of a modified Adel 20653 electric-driven fuel pump (identified by either a 1/8 inch red band around the pump body, or the suffix "H" in the pump serial number, in series with a modified Thompson TF-1100 engine-driven fuel pump (identified by a "2" or "M2" stamped after the TF-1100 on the nameplate)) installed in accordance with Beech Installation Instructions, revised March 31, 1949, are not affected by this Airworthiness Directive.
(Beech Letter D-49-540 dated January 7, 1949, and Installation Instructions for the Model 35 Electric-Driven Auxiliary Fuel Pump, revised March 31, 1949, covers this same subject.)
This supersedes AD 49-28-02.