There are network effects actually.

Bombardier is one of the main anchors around which many major aircraft industry company are located. In turn those suppliers also help explain the Bell Helicopter Textron plant.

I'm thinking of companies like Safran Landing Systems (formerly Messier-Dowty), Pratt-Whitney Canada (one of, if not the, largest producer of turboprops and turboshafts engines), CAE (sims, avionic), Thales (avionic), Héroux-Devtek (landing gears), etc. Plus all the smaller subcontractors.