47-10-29 LOCKHEED: (Was Mandatory Note 32 of AD-763-3.) Applies to All Model 49 Serials Prior to 2080 on Which Metal Ailerons Are Installed.
Compliance required prior to April 1, 1947.
Between aileron Stations 69.5 and 99.7, install drain holes in the lower aileron surface outboard of each rib and forward of each stringer (17 holes total).
(LAC Service Bulletin 49/SB-214 covers this same subject.)