A heat exchanger for providing thermal energy transfer between a first flow along a first flowpath and a second flow along a second flowpath has at least one plate bank having a plurality of plates, each plate having: a first face and a second face opposite the first face; a leading edge along the second flowpath and a trailing edge along the second flowpath; a proximal edge having at least one inlet port along the first flowpath and at least one outlet port along the first flowpath; and at least one passageway along the first flowpath. An inlet manifold has a first face to which the plurality of plates are mounted along their respective proximal edges. An inlet plenum has at least one inlet port and at least one outlet port. An outlet plenum has at least one outlet port and at least one inlet port. The first flowpath passes from the at least one inlet port of the inlet plenum, through the at least one passageway of each of the plurality of plates, and through the at least one outlet port of the outlet plenum. For each plate, the manifold first face has a respective associated slot capturing a portion of the plate along the proximal edge thereof to prevent extraction of the plate normal to the manifold first face.