I worked at Lockheed Martin as a Systems Engineer for a few years. Everything we worked on as a project was waterfall. We did annual training using the method

I worked at Lockheed Martin as a Systems Engineer for a few years. Everything we worked on as a project was waterfall. We did annual training using the methodology and did exercises around it as well. I think it's rather commonplace for defense contractors and wouldn't be surprised if this were still the case for Boeing.