47-43-10 LOCKHEED: (Was Mandatory Note 21 of AD-723-3.) Applies to All Model 18 Serial Numbers.
Compliance required prior to February 1, 1948.
Inspect all Alfite Model 2CD1722 operating heads for the CO2 bottles (fire extinguishing system) and nitrogen bottles (emergency landing gear extension system) to determine whether these heads have been stamped with the letter "L" adjacent to the swivelnut. If the head is not marked in this manner, disassemble the head and examine the cable sheave for part number. All 2CD2248 sheaves should be reworked by rounding the inner shoulder of the ramp at its lower end throughout a distance of 1 1/4 inches, to eliminate possible jamming of the mechanism. When reworked sheaves are installed, the operating heads should be identified by the letter "R" stamped adjacent to the swivelnut.
(Lockheed Service Bulletin 18/SB-140 covers this same subject.)