Demonstrated productivity skills and abilities on current job plus 1 year experience at level "C", 200 hours of vocational machine shop training and 6 months evaluation period, or 1 year experience at level "D", with 270 hours of vocational machine shop training and 6 months evaluation period, or 1 year experience at level "D", with 270 hours of vocational machine shop training and 6 months evaluation period. Our systems are on board 90% of the world''s aircraft - serving commercial aviation, defense and space operators from integrated flight deck platforms with 30-plus years in service to radiation-hardened systems trusted for human spaceflight.