Production ran from 1983 until 2002. Manufacture of an improved version known as the Avro RJ began in 1992. A further-improved version with new engines, the Avro RJX, was announced in 1997, but only two prototypes and one production aircraft were built before production ceased in 2001. With 387 aircraft produced, the Avro RJ/BAe 146 is the most successful British civil jet airliner programme. The BAe 146/Avro RJ is a high-wing cantilever monoplane with a T-tail. It has four turbofan engines mounted on pylons underneath the wings, and has retractable tricycle landing gear. The aircraft has very quiet operation, and has been marketed under the name Whisperjet. It sees wide usage at small, city-based airports such as London City Airport. In its primary role, it serves as a regional jet, short-haul airliner, or regional airliner, while examples of the type are also in use as private jets. The BAe 146/Avro RJ is in wide use with several European-based carriers such as CityJet. The largest operator of the type, Swiss Global Air Lines, retired its last RJ100 in August 2017. Firefighting air tanker conversions Firefighting air tanker versions of both the BAe 146 and the Avro RJ85 have been manufactured by the conversion of aircraft previously operated by airlines in scheduled passenger service. These aircraft have been used in fighting bushfires in Australia. For more details on the BAe 146, click here.