65-19-01 AIR and SPACE: Amdt. 39-122 Part 39 Federal Register August 25, 1965. Applies to Model 18A Gyroplanes, Serial Numbers 18-7 through 18-28.
Compliance required before further flight unless already accomplished.
To prevent further failures of main rotor blade retention bolts while supporting the blade near the tip to prevent contact with the droop stops, replace three main rotor blade retention bolts, P/N RO-U18-2136-11, and nuts, P/N MS-20364-1614, with new main rotor blade retention bolts and nuts furnished by the manufacturer after August 4, 1965, and torque the nuts to 45 - 50 foot pounds dry thread torque value.
This directive effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated August 10, 1965.