A well-prepared person - thermal clothing, supplemental oxygen, restraint system, knowledge of the landing gear bays - could easily pull it off.
Pity that such a well prepared and well equipped person won't be living in an African slum in the first place, and hence would not be motivated to attempt such a dangerous stunt. Your run-of-the-mill desperate slum dweller has nothing to his name except the clothes on his back and has very little to no knowledge at all of the world outside his slum.
