I assume they are using a Russian helicopter to keep a low profile. Something like a Chinook, Seaknight or Blackhawk would be a dead giveaway as to who the helicopter belonged to.
It probably wouldn't be all that difficult for someone like the CIA
to purchase helicopters on the black market in Africa. They had their own Air Force in Air America during the war in Southeast Asia. I wonder if the military keeps a secret fleet of foreign aircraft for ops like this? Does this thing have a registration number? Very interesting.