JAKARTA — The Indonesian airline industry has made progress toward mending its reputation — amid soaring demand — after a series of spectacular crashes in recent years drew international attention to the country’s poor safety record. Now it has a new problem to deal with: drug abuse among its pilots.

The police arrested a pilot from the country’s largest private airline, Lion Air, last Saturday on suspicion of possessing crystal methamphetamine, a psychostimulant that increases alertness and concentration and can create feelings of euphoria.

It was the fourth such arrest of a Lion Air employee in seven months, raising fresh concerns about the airline industry’s safety and security standards, and heightening pressure on the government to enact stricter airline regulations.

Rising demand from Indonesia’s growing middle class has pushed airlines to add routes and purchase more planes.