American Airlines, using American Eagle equipment, is by far the world’s largest user of regional jets. According to ch-aviation, Eagle has currently has 582 RJs, comprising 224 E175s, 129 CRJ700s, 91 ERJ145s, 86 CRJ900s, and 52 E170s. They are flown by Envoy Air, PSA, Piedmont, Republic, and SkyWest.