CAA (Compagnie Aerienne Africain), they have ~ 2 MD-80s and one B727 freighter.
I believe Bravo Air Congo is still flying (at least they were in late Dec when I left DRC), they had a couple DC-9's but their fleet and route network had shrunk considerably because of an incident/accident in the Equator region (Mbandaka? Gemena? Anyone know the facts, I hear varying stories on this).
There is another company, Transair? that flies a DC-8 between Kinshasa and Lubumbashi, I think they have a YS-11 that is working in Katanga.
In Lubumbashi, Air Katanga or ITAB operate a couple old school Hawker bizjets. There are also a couple flight departments for mining operators.
I'd suspect there's some other Congolese jet activity in N'djili like Kabila's B727 and Gulfstream, but haven't been there lately.
jt