Narrative:

Contractor ordered the raw stock as post heat treat and received it as such.airline had paid contractor to make a lot of 8; to be used on our airplanes. There were several in use already. The manufacturing data wasn't clear; (that) the heat treat had yet to be done.the B737-900 was aog (aircraft on ground) for this part. Contractor determined that a repair doubler they had installed on aircraft did not get the required heat treatment. I was presented with another doubler that was supposed to have the heat treatment completed.the certification for the part also had information relating to the hardness of the material under H900 code results. The 'a'; or annealed; code had no results shown. I interpreted this as having the treatment H900 complete. A batch of 8 was made; to be used on airline's airplanes and were here as repair parts for that airline only. I inspected the data and one part; and determined that this part was fabricated correctly using the structural repair manual (srm); reference 57-51-02 repair 1. I created a parts transfer form and sent part to where it was put on aircraft. I was informed a week later that the heat treatment was not performed on this part and the results were only values that would be achieved when the H900 treatment is accomplished. I and everyone involved was misunderstanding the data.

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Original NASA ASRS Text

Title: An Inspector reported that a Maintenance Contractor had installed a doubler repair on a B737-900 aircraft without the proper heat treatment process being applied to the doubler. The replacement doubler he inspected also did not have the heat treatment accomplished because of a misunderstanding of manufacturer's data.

Narrative: Contractor ordered the raw stock as post heat treat and received it as such.Airline had paid Contractor to make a lot of 8; to be used on our airplanes. There were several in use already. The manufacturing data wasn't clear; (that) the heat treat had yet to be done.The B737-900 was AOG (Aircraft on Ground) for this part. Contractor determined that a repair doubler they had installed on aircraft did not get the required heat treatment. I was presented with another doubler that was supposed to have the heat treatment completed.The certification for the part also had information relating to the hardness of the material under H900 code results. The 'A'; or annealed; code had no results shown. I interpreted this as having the treatment H900 complete. A batch of 8 was made; to be used on airline's airplanes and were here as repair parts for that airline only. I inspected the data and one part; and determined that this part was fabricated correctly using the structural repair manual (SRM); reference 57-51-02 repair 1. I created a parts transfer form and sent part to where it was put on aircraft. I was informed a week later that the heat treatment was not performed on this part and the results were only values that would be achieved when the H900 treatment is accomplished. I and everyone involved was misunderstanding the data.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.