47-34-02 BEECH: (Was Mandatory Note 3 of AD-770-1 and Mandatory Note 4 of AD- 765-1.) Applies to D18S, D18C and D18C-T Airplanes Which Do Not Have Drain Provisions at Bulkhead No. 15.
Compliance required prior to December 1, 1947.
To provide additional drainage, to prevent freezing of trapped moisture in the tail cone which could jam the elevator control system, a 3/4-inch diameter hole should be drilled near the front of the tail cone outer section on the centerline of the lower surface. A suitable marine grommet should be installed to provide for negative pressures. Also a 1/2-inch diameter hole should be drilled on each side of the jack pad through the lower part of bulkhead No. 15.
(Beech Service Bulletin D18-46 covers this same subject.)