Narrative:

I was grinding [internal] chamfers on an oil pressure regulator housing and it was determined that there was not currently a method to measure the chamfer to ensure that it was in tolerance in-accordance with (in accordance with) figure 901; page 902. Item number 2 of that figure; references a chamfer between two internal diameters and states the tolerances as 0.030 inch to 0.050 inch depth x 43 to 47 degrees. There are specific measurements called out for the finish diameter of the internal bore and concentricity requirements between the larger internal diameter and the repaired bore. But there are no specific concentricity called out for the chamfer.

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Original NASA ASRS Text

Title: A Shop Mechanic reports about an FAA Inspector who questions why repair procedures on their PW JT8-217 engine oil pressure regulating valves do not have specific degree concentricity requirements for the chamfers around the internal bore openings.

Narrative: I was grinding [internal] chamfers on an oil pressure regulator housing and it was determined that there was not currently a method to measure the chamfer to ensure that it was in tolerance In-Accordance With (IAW) Figure 901; Page 902. Item number 2 of that figure; references a chamfer between two internal diameters and states the tolerances as 0.030 inch to 0.050 inch depth x 43 to 47 degrees. There are specific measurements called out for the finish diameter of the internal bore and concentricity requirements between the larger internal diameter and the repaired bore. But there are no specific concentricity called out for the chamfer.

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.