The Pentagon quietly ended a program to train Afghan Air Force pilots in the United States after nearly half of the course attendees disappeared, according to a Defense Department watchdog report released this week.

More than 40 percent of the Afghan pilots sent to train on the AC-208 Combat Caravan lightweight reconnaissance aircraft went absent without leave while in the United States, according to a quarterly report of the Special Inspector General for Afghanistan Reconstruction, or SIGAR. The report, which was released Tuesday, did not detail precisely how many Afghan pilots deserted the training program, which has been conducted at the Fort Worth Meacham Airport in Texas.