Airworthiness Directive · Amendment 39-15042 · Air Tractor, Inc. Model AT-602 Airplanes
Air Tractor, Inc. Model AT-602 Airplanes
This AD applies to Model AT-602 airplanes, all serial numbers through 602-0695 that:
(1) Have horizontal stabilizer brace tube assembly, part number (P/N) 30012-7, installed; and
(2) Are certificated in any category.
We are adopting a new airworthiness directive (AD) for certain Air Tractor, Inc. (Air Tractor) Model AT-602 airplanes. This AD requires you to install access holes to do repetitive detailed visual inspections for cracks in the horizontal stabilizer brace tube assembly, and if any cracks are found as a result of a visual inspection, to replace the horizontal stabilizer brace tube assembly with a new design horizontal stabilizer brace tube assembly. The installation of the new design horizontal stabilizer brace tube assembly is terminating action for the repetitive inspection requirement. This AD results from two reports of Model AT-602 airplanes with cracked horizontal stabilizer brace tube assemblies. We are issuing this AD to detect and correct cracks in the horizontal stabilizer brace tube assembly, which could result in failure of the horizontal stabilizer. This failure could affect the ability to control pitch with consequent loss of control.
To address this problem, you must do the following, unless already done:
| Actions | Compliance | Procedures |
|---|---|---|
| (1) Do the following: (i) Install access holes for visual inspection of the P/N 30012-7, horizontal stabilizer brace tube assembly. (ii) Conduct a detailed visual inspection for cracks in the P/N 30012-7 horizontal stabilizer brace tube assembly. | Install the access holes and do the initial inspection upon accumulating 2,000 hours time-in-service (TIS) or within the next 60 days after June 12, 2007 (the effective date of this AD), whichever occurs later. Repetitively inspect thereafter at intervals not to exceed 100 hours TIS. Replacement of the P/N 30012-7 horizontal stabilizer brace tube assembly with a new design P/N 30766-1 horizontal stabilizer brace tube assembly following paragraph (e)(2) of this AD is terminating action for the repetitive inspection requirement of this AD | Follow Snow Engineering Co. Service Letter #235, dated August 25, 2004, revised October 24, 2006. |
| (2) Replace the P/N 30012-7 horizontal stabilizer brace tube assembly with a new design P/N 30766-1 horizontal stabilizer brace tube assembly | Before further flight after any inspection required by paragraph (e)(1) of this AD where cracks are found. The installation of a new design P/N 30766-1 horizontal stabilizer brace tube assembly is terminating action for the repetitive inspection requirement of this AD | Follow Snow Engineering Co. Service Letter #129A, dated August 7, 2004, revised November 15, 2005; Snow Engineering Co. Service Letter #235, dated August 25, 2004, revised October 24, 2006; and Snow Engineering Co. Drill Template—602, Drawing Number SL129-602, dated August 2, 2004. |
| (3) Do not install any P/N 30012-7 horizontal stabilizer brace tube assembly | As of June 12, 2007 (the effective date of this AD) | Not Applicable. |
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
