In The Case of the Visiting Sultan, Oba I'Mobi was the Sultan of Lashanti, a West African sultanate which was also a British colony under the governorship of Sir Milton Chambers. The sultan was a young man with progressive ideas, having been educated in Britain. Among his qualifications, he possessed a "B" licence (a commercial pilot's licence) and owned an ex-R.A.F photo-reconnaissance de Havilland Mosquito. When it was time to travel to London for a colonial conference, the Sultan chose to fly to London by piloting his own Mosquito, and carry his younger son as well as his royal regalia.
When Air Commodore Raymond learned that American master criminal Rocky Cordova was in West Africa, he suspected that he might be planning to rob the Sultan by ambushing his aircraft while in transit. Diplomatic niceties made it impossible to give the Sultan regular service protection so Biggles was asked to provide some discreet cover for the flight.
After starting a rumour that the Sultan would be departing for London an hour ahead of schedule, Biggles flew a Mosquito along the Sultan's intended route as an advance decoy. As expected, he was ambushed by Rocky Cordova and his pilot Juan Laroula flying an ex-American Cobra attack aircraft. In the ensuing dogfight, Biggles outclassed his opposition and shot the Cobra down, killing both of the criminals. The Sultan's flight went through without incident and without him knowing anything about what had happened.