The people who made the dumb mistake that led to the Alaska Airlines blowout that could have been deadly quite easily were all union members. They worked around the system, removed bolts, did some work, forgot to put back bolts in. (I say they because Boeing, negligently, has no records of who did what, so the whole team of 20 people is responsible).

The main theme for Boeing in the past few decades has been lowering costs. Be it by forcing the hands of unions to lower salaries and benefits, or moving production to non-union places (787s in South Carolina), or offloading as much design and manufacturing work to subcontractors as possible, spinning off "unrelated" business such as manufacturing. Most of those were absolute disasters.