Abstract: A surface heat exchanger for an aircraft turbomachine includes a support wall, a panel parallel to the support wall, partitions connecting the wall to the panel to define channels in which an air flow flows, and fins situated in the channels. The panel has a central part parallel to the wall and a downstream part that is inclined with respect to the wall. An upstream end is connected to the central part and a downstream end is situated at a distance from the wall and delimits with the latter a main outlet of the channels. The downstream part has fixed flaps disposed one after another so as to delimit between one another additional outlets of the channels.