There are two solids in file body.brep and wing.brep, load them from the files.
The code snippet to do the boolean fuse operation are as below:
TopoDS_Shape aBody = ...
TopoDS_Shape aWing = ...
BRepAlgoAPI_Fuse aMakeFuse(aBody, aWing);
The generated result can pass check of following but the result is invalid:
Steps To Reproduce
restore body.brep b
restore wing.brep w
bfuse r b w