53-23-02 de HAVILLAND: Applies to Model DHC-2 (Beaver) Aircraft, Serial Numbers 164 to 407 Inclusive.
Compliance required not later than December 15, 1953.
When filling the fuel tanks, it is possible for spilled fuel to seep down between the fuel tank filler neck recess box and the aircraft's outer skin. This permits gasoline fumes to accumulate in the tank bays beneath the floor and can create a fire hazard. The aircraft should be inspected to ascertain if a satisfactory seal exists between the filler neck recess box (C2-FS-1005ND) and the outer skin (C2-S-829ND). If seal is unsatisfactory, fill gap with either "Goodyear Plyabond" or "Minneapolis Mining EC776" metal sealing compounds or equivalent. In the interim, until resealing is accomplished, a "No Smoking" placard should be installed in the cabin. The FAA concurs in this mandatory action by the Canadian Department of Transport.
(de Havilland Technical News Sheet No. 68, Series B, dated September 15, 1953,covers this same subject and provides resealing instructions.)