In Biggles Makes Ends Meet, General Cotter was a United States Air Force general officer whose troops intervened at a crucial moment, overcoming the forces of Colonel Black's smuggling gang and capturing his secret island base, just as Biggles, Bertie and Algy were hard pressed and in danger of being overwhelmed.
Earlier, Bertie and Algy had managed to take photos of Colonel Black in Kuala Lumpur. Biggles had these photos wired back to London from Singapore. The U.S. authorities had been searching for the Colonel for some time and were highly excited to learn that Biggles had found him. American Headquarters in Formosa (today Taiwan) was notified, and General Cotter, apparently based there, was activated and asked to apprehend the Colonel.
When Ginger, having escaped from the secret island base, arrived at Kuala Lumpur, he received a message asking him to wait for General Cotter and guide him and his troop transport aircraft to the secret island base. The General's two Globemasters carrying a strong detachment of US marines proved more than enough to deal with any resistance and take Colonel Black into custody.