68-20-06 NAVION: Amendment 39-663. Applies to Navion through Navion H airplanes.
Compliance required within the next 50 hours time in service after the effective date of this AD, and each annual inspection thereafter.
To prevent failure of the Rudder Horn, P/N 145-24401, accomplish the following:
Inspect for horizontal cracks or corrosion in the edge of the rudder horn. These cracks would appear as delaminations or swelling under the paint. Replace corroded or cracked rudder horns with new or unused part of the same part number or Federal Aviation Administration approved equivalent part before further flight.
This amendment becomes effective October 3, 1968.