A small population of large (“heavy”) transport and vintage aircraft powered by commensurately large air-cooled radial and liquid-cooled inline piston engines remains active in the U.S. and abroad that cannot be operated on any fuel other than 100/115-octane leaded aviation gasoline.

The archipelago nation of the Philippines has had a long relationship with the United States dating from the end of the Spanish-American war in 1898 when the islands were ceded to the U.S. as a protectorate, in effect, becoming an American colony and Southeast Asian outpost.

It's one of your worst nightmares. You’ve captained a trip to a remote area of an African country, and your first officer and one of the executive passengers have contracted a local disease — maybe dengue fever, but you’re not sure. The trip came up fast, and researching disease hazards and health care infrastructure was definitely not on your mind. But it sure is now, as you scramble to cope with a situation you never had time to envision.