TailplateTailplate
Run a report

Airworthiness Directive 2008-21-08

recurring
Official AD 2008-21-08 · FR doc E8-24137 · 2008-10-16 · airframe

Airworthiness Directives; Air Tractor, Inc. Models AT-402, AT-402A, and AT-402B Airplanes

What this AD requires

We are adopting a new airworthiness directive (AD) for certain Air Tractor, Inc. (Air Tractor) Models AT-402, AT-402A, and AT-402B airplanes. This AD requires you to repetitively visually inspect the rudder and vertical fin hinge attaching structure for loose fasteners and inspect the rudder or vertical fin skins, spars, hinges, or brackets for cracks and/or corrosion. This AD also requires you to replace any damaged parts found as a result of the inspections and install an external doubler at the upper rudder hinge. Installation of the external doubler at the upper rudder hinge is terminating action for the repetitive inspection requirements. This AD results from a report of a Model AT-402 airplane with a loose upper rudder hinge caused by fatigue. We are issuing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges, or brackets; or corrosion of the rudder and vertical fin hinge attaching structure. Hinge failure adversely affects ability to control yaw and has led to the rudder folding over in flight. This condition could allow the rudder to contact the elevator and affect ability to control pitch with consequent loss of control.

Repetitive inspection. Re-inspect every 100 hours. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2008-21-08 applies to

MakesAir Tractor
ModelsAT-402, AT-402A, AT-402B
Serial-conditional — narrows to serials 0694–1176.

Whether AD 2008-21-08 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.

How AD compliance is recorded

A valid compliance record (14 CFR 43.9) states:

Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.
Date — When the work was done.
Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.
Signature & certificate — The A&P/IA who returned it to service, with certificate number.
Is AD 2008-21-08 complied with on your aircraft?

Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.

Look up a tail number →Read the full directive (Federal Register)

Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.