After spending nearly half a billion dollars on 20 planes to outfit the Afghan Air Force, the Defense Department turned around and scrapped 16 of the aircraft for 6 cents on the pound—just $32,000, the Special Inspector General for Afghanistan Reconstruction has learned.

The Defense Logistics Agency carried out the planes’ destruction at Kabul International Airport as the SIGAR was investigating the Defense Department’s failed program to outfit the Afghans with a fleet of twin propeller military transport aircraft. The G222 aircraft, manufactured in Italy, proved impossible for the Afghan military to maintain and the Pentagon terminated the program in March 2013, three months after the SIGAR initiated its investigation. By then, the department had spent at least $486 million on the aircraft.

SIGAR determined that the aircraft flew only 234 hours out of 4,500 required from January through September 2012.

In a pointed letter to Air Force Secretary Deborah James, John Sopko requested all documentation surrounding the decision to scrap the planes along with an explanation. Specifically, he wants to know why the planes weren’t flown out of the country to be sold elsewhere and what steps the department took to obtain a refund.

What’s more, Sopko wants to know the end use of the scrap metal sold to an Afghan company and the ultimate fate of parts that weren’t scrapped, such as engines and brass components. In a country where such materials often end up as components in weapons used against U.S. troops, the answers could prove deeply troubling to U.S. and Afghan officials.

The remaining four aircraft of the original 20 are at Ramstein Air Force Base in Germany. In a separate letter to Defense Secretary Chuck Hagel, Sopko requested advance notice before the remaining planes are moved or destroyed.