Applies To Certain AT-402/402A/402B, AT-502/502A/502B, AT-602, And AT-802/802A Airplanes

A Special Airworthiness Information Bulletin (SAIB) issued by the FAA provides inspection procedures and on-condition maintenance actions for the rudder upper hinge for Air Tractor, Inc. Models AT-402/402A/402B, AT-502/502A/502B, AT-602, And AT-802/802A Airplanes, all serial numbers (under Type Certificate Data Sheets A17SW and A19SW).

According to the FAA, Air Tractor, Inc. recently issued Snow Engineering Co. Service Letter (SL) #331 for all Models AT-402/402A/402B, AT-502/502A/502B, AT-602, and AT-802/802A airplanes. The SL was issued after an operator reported finding sheared rivets in the rudder upper hinge support bracket on one airplane. The SL provides owners and operators instructions for inspecting the rudder upper hinge and surrounding structure for hinge movement relative to the rudder, and for cracks in the skins, spars, hinge brackets, or doublers.

An initial inspection is specified within 100 flight hours with repeat inspections 300 hours/annually thereafter, and repair or replacement of damaged parts when found. SL #331 also requests you report your inspection results to the Air Tractor Service Department using the contact information provided.

The FAA recommends inspecting, and repairing or replacing when required, the rudder upper hinge and surrounding structure in Air Tractor, Inc. AT-402/402A/402B, AT-502/502A/502B, AT-602, and AT-802/802A airplanes using the procedures in SL #331, and to report inspection findings to the Air Tractor Service Department.

FMI: SAIB