In The Case of the Visiting Sultan, Juan Laroula was an employee and the personal pilot of American master criminal Rocky Cordova. A Mexican pilot who served with the U.S. Army Air Force during the Second World War, Laroula served for two years on the cargo route transporting war supplies from the West coast of Africa to Egypt.
Laroula flew Rocky Cordova's Cobra attack aircraft when he and his employer planned to ambush the Mosquito of the Sultan of Lashanti while it was enroute to London. Unfortunately for Laroula, Biggles was also flying a Mosquito as a decoy. Laroula took the bait and attacked Biggles thinking he was the Sultan. In the ensuing dogfight, Biggles hit Laroula several times, holing his fuel tanks. Laroula turned his aircraft and fired his guns. His tracer cut through the vapour trail of his own damaged aircraft, causing an explosion which killed both himself and Cordova, who was a passenger on board the Cobra.