A Lathe Machinist reports their machine shop was recently informed they had been manufacturing repair bushings for a main landing gear secondary strut and main gear trailing arm assemblies with the wrong material for three years.

Narrative

On an Air Carrier's Regional Jet main gear; I used the incorrect revision of the Air Carrier's bshing blueprints to manufacture repair bushings. Details as follow: main gear secondary strut bushing IPC 32-10-04 (Illustrated Parts Catalog) item 390; Carrier's Engineering blueprint parts equivalent and interchangeable list; this bushing is a -17. The -17 bushing was manufactured per engineering blueprint and the material specification calls out using S-4640 material. On the [current] engineering blueprint revision; material was changed to manufacture the -17 bushing with 17-4PH material. Not aware of the blueprint change; we continued to manufacture the -17 bushing with the wrong material from [revision issue date] to date found.The Air Carrier's Regional jet main gear trailing arm assemblies part number #2309- XXXX; 2309-YYYY; 2309-ZZZZ; and 2309-XYZA bushings found in IPC 32-10-01; item 40; with PN #2309- per engineering blueprint parts equivalent and interchangeable list; this bushing is a -5. The -5 bushing was manufactured using 17-4PH material in the shop. The -5 bushing should have been S-4640 material. But on [our] engineering revision 'E' dated May 2010 the material called out changed to 304SS to be used. Not aware of the material requirements we manufactured the -5 bushing with the wrong material until found.Air Carrier's Regional Jet main gear trailing arm assemblies PN # 2309-AAAA; 2309-BBBB; and 2309-CCCC and bushings IPC 32-10-01; item 120; PN # 2309-DDDD; per Air Carrier's engineering blueprint parts equivalent and interchangeable list; this bushing is a -3. The -3 bushing was manufactured in shop using 15-5 PH material. The -5 bushing should have been S-4640 material. On Air Carrier's Engineering Revision 'E' dated May 2010 the material calls out for 15-5 PH.