This unusual-looking aircraft, registered as C-GSUI, is a British Aerospace Avro RJ100!

North Cariboo Air is a regional charter based in Canada. It currently operates six airplanes, two of which are RJ100s. The RJ100 is based on the BAe 146-300, but with interior, engine and avionics improvements.

Back in the day, carriers like Pacific Southwest (or PSA) and USAir operated these aircraft as regional airliners.