In Biggles in the Orient, Biggles and his squadron made a transit stop at Drigh Road Airfield, Karachi, on their way to their destination Calcutta. At Drigh Road, they changed from a Wellington to a Liberator for their onward journey.
Drigh Road Airfield, Karachi, is the oldest air base in Pakistan and one of the most famous. Founded soon after RAF India Command was formed in 1918 as an aircraft depot, its main mission at the time was to receive aircraft in knocked down condition off ships, assemble, test fly and then ferry them to squadrons all over India. Here, in 1927, among a group of airmen arriving from Britain was AC2 T. E. Shaw (formerly T. E. Lawrence), who worked in the Engine Repair Shop for over a year. Lawrence's letters to his mother contain interesting details of life at Drigh Road at the time. Drigh Road was also the birth place of the Indian Air Force, as No.1 Squadron IAF was raised there on 1st April 1933 at Drigh Road, Karachi.
In 1942, the Aircraft Depot was redesignated No 1 (India) Maintenance Unit and served as the main supply base not only for the RAF in India but for all of the Burmese and Malayan campaigns. Practically every new aircraft destined for these fronts would have passed through Drigh Road.
In 1947, Drigh Road was handed over to the Pakistan Air Force and it continues to this day as PAF Faisal Airbase.
Also in Karachi was RAF Mauripur (now Masroor Airbase) which was founded in 1942 to serve as a transit airfield to relieve Drigh Road of transit traffic and allow it to focus on its role as a maintenance base. So Mauripur would have been a more appropriate transit stop for Biggles and his squadron, although Drigh Road was probably more well-known to Johns. Still, there could be plausible reasons why Biggles was taken to Drigh Road. The Wing Commander who greeted Biggles there said his "best Liberator" was waiting for him. This Liberator could have just been shipped in and gone through maintenance and test flights and was ready to be ferried to Dum Dum, Calcutta, and it was convenient for Biggles and his squadron to go along in it.