The NATA Alternative Means of Compliance (AMOC) for AD 2005-12-51 (T-6/SNJ/Harvard wing attach angles) extends the upper angle inspection interval to 1000 hours time-in-service (TIS). Some areas of the lower attach angles still require inspection every 200 hours TIS, but the total area of the lower angles requiring inspection is greatly reduced under the NATA AMOC.
In order to begin using the inspection intervals of the NATA AMOC all the upper and lower attach angles must have been inspected per AD2005-12-51 within the previous 200 hours TIS. The NATA AMOC inspection intervals may then be used for the next 1000 hours TIS after which another complete inspection of all the top and bottom angles is required. The inspection intervals then revert back to that of the NATA AMOC for the next 1000 hours and so on.
The NATA AMOC allows the use of either dye penetrant or eddy current methods of crack detection. Those providing eddy current inspections must possess specific FAA approvals to perform an eddy current inspection on the attach angles. If cracks, corrosion or other damage is found, the entire affected attach angle must be replaced. As per NAA Structural Repair Instructions T.O. AN01-60F-3 no splicing or repairs to wing attach angles are permitted.
NATA members may purchase the AMOC for $350, which is aircraft-specific, by serial # (must be provided at time of purchase).
You may purchase the AMOC online or contact NATA for further information. (The link will only work if you are logged in.)