Hi,
About the cargo and other details: (From latest bulletin news RTBF1 mainstream belgian TV)
Plane in official leasing by the US governement.
Brussels was just a technical stop on his way from USA to the Gulf.
Diplomatics documents aboard
A official diplomatic car aboard
A diplomatic case aboard
Other goods not described in details by authorities but explained as non dangerous for the peoples or environment (the most dangerous goods is the kerosen itself)
US diplomats delegation waiting the green light from the belgian safety authorities for have acces to the plane.
Cheers.