Various improved versions of the Halifax were introduced, incorporating more powerful engines, a revised defensive turret layout and increased payload. It remained in service with Bomber Command until the end of the war, performing a variety of duties in addition to bombing. Additionally, specialised versions of the Halifax were developed for troop transport and paradrop operations. Following the end of the Second World War, the RAF quickly phased the Halifax out of service, after the type was succeeded in the strategic bombing role by the Avro Lincoln, an advanced derivative of the Lancaster. During the post-war years, the Halifax was operated by the Royal Egyptian Air Force, the French Air Force and the Royal Pakistan Air Force. The type also entered commercial service for a number of years, used mainly as a freighter. A dedicated civil transport variant, the Handley Page Halton, was also developed and entered airline service. 41 civil Halifax freighters were used during the Berlin Airlift. In 1961, the last remaining Halifax bombers were retired from operational use.