diff --git a/raptor/ruge_stuben/par_air_solver.hpp b/raptor/ruge_stuben/par_air_solver.hpp
index b53d03f6..26620add 100644
--- a/raptor/ruge_stuben/par_air_solver.hpp
+++ b/raptor/ruge_stuben/par_air_solver.hpp
@@ -34,7 +34,7 @@ struct ParAIRSolver : ParMultilevel {
 		ParCSRMatrix *A = levels[level_ctr]->A;
 		ParBSRMatrix *A_bsr = dynamic_cast<ParBSRMatrix*>(A);
 		if (A_bsr) extend_hier(*A_bsr);
-		// else extend_hier(*A);
+		else extend_hier(*A);
 	}
 
 private:
@@ -50,7 +50,45 @@ struct ParAIRSolver : ParMultilevel {
 		auto P = one_point_interpolation(A, *S, split);
 		auto R = local_air(A, *S, split, fpoint_distance::two);
 
+		levels.back()->P = P;
 		levels.emplace_back(new ParLevel());
+		auto & level = *levels.back();
+		auto AP = A.mult(P, tap_level);
+		auto coarse_A = R->mult(AP);
+		// auto coarse_A = AP->mult_T(P, tap_level);
+
+		level.A = coarse_A;
+
+		finalize_coarse_op(tap_amg >= 0 && tap_amg <= level_ctr + 1);
+		init_coarse_vectors();
+
+		level.P = nullptr;
+
+		delete AP;
+		delete S;
+	}
+
+	void finalize_coarse_op(bool tap_init) {
+		auto & coarse_op = *levels.back()->A;
+		auto & fine_op = *(**(levels.end() - 2)).A;
+
+		coarse_op.sort();
+		coarse_op.on_proc->move_diag();
+		coarse_op.comm = new ParComm(coarse_op.partition, coarse_op.off_proc_column_map,
+		                             coarse_op.on_proc_column_map,
+		                             fine_op.comm->key, fine_op.comm->mpi_comm);
+
+		if (tap_init) {
+			coarse_op.init_tap_communicators(RAPtor_MPI_COMM_WORLD);
+		}
+	}
+
+	void init_coarse_vectors() {
+		auto & clevel = *levels.back();
+		[global_rows = clevel.A->global_num_rows,
+		 local_rows = clevel.A->local_num_rows](auto & ... vecs) {
+			(vecs.resize(global_rows, local_rows),...);
+		}(clevel.x, clevel.b, clevel.tmp);
 	}
 
 	coarsen_t coarsen_type;
diff --git a/raptor/ruge_stuben/par_interpolation.cpp b/raptor/ruge_stuben/par_interpolation.cpp
index babadc23..6fb62909 100644
--- a/raptor/ruge_stuben/par_interpolation.cpp
+++ b/raptor/ruge_stuben/par_interpolation.cpp
@@ -2143,6 +2143,19 @@ T * create_R(const T & A,
 		return global;
 	}(local_rows);
 
+
+	auto local_rowmap = [local_rows]() {
+		auto row_start = [](int local) {
+			MPI_Exscan(MPI_IN_PLACE, &local, 1, MPI_INT, MPI_SUM, RAPtor_MPI_COMM_WORLD);
+			return local;
+		}(local_rows);
+
+		std::cout << row_start << std::endl;
+		std::vector<int> rowmap(local_rows);
+		std::iota(std::begin(rowmap), std::end(rowmap), row_start);
+		return rowmap;
+	};
+
 	auto off_proc_num_cols = rowptr_and_colmap.offd_colmap.size();
 	auto move_data = [&](offd_map_rowptr && rac, ParMatrix & mat) {
 		mat.on_proc->idx1 = std::move(rac.diag_rowptr);
@@ -2163,11 +2176,13 @@ T * create_R(const T & A,
 		                            local_rows, S.on_proc_num_cols, off_proc_num_cols,
 		                            A.on_proc->b_rows, A.on_proc->b_cols);
 		move_data(std::move(rowptr_and_colmap), *R);
+		R->local_row_map = local_rowmap();
 		return R;
 	} else {
 		auto * R = new ParCSRMatrix(S.partition, global_rows, S.global_num_cols,
 		                            local_rows, S.on_proc_num_cols, off_proc_num_cols);
 		move_data(std::move(rowptr_and_colmap), *R);
+		R->local_row_map = local_rowmap();
 		return R;
 	}
 }
diff --git a/raptor/ruge_stuben/tests/test_air.cpp b/raptor/ruge_stuben/tests/test_air.cpp
index 498e1bf1..58cf287d 100644
--- a/raptor/ruge_stuben/tests/test_air.cpp
+++ b/raptor/ruge_stuben/tests/test_air.cpp
@@ -1,6 +1,7 @@
 #include "gtest/gtest.h"
 
 #include "raptor/raptor.hpp"
+#include "raptor/ruge_stuben/par_air_solver.hpp"
 #include "raptor/tests/compare.hpp"
 
 using namespace raptor;
@@ -14,6 +15,7 @@ int main(int argc, char** argv)
     return ret;
 }
 
+#if 0
 TEST(TestOnePointInterp, TestsInRuge_Stuben) {
 	int rank; MPI_Comm_rank(MPI_COMM_WORLD, &rank);
 	constexpr std::size_t n{16};
@@ -141,7 +143,6 @@ TEST(TestLocalAIR, TestsInRuge_Stuben) {
 	}
 }
 
-#if 0
 TEST(TestLocalAIRBSR, TestsInRuge_Stuben) {
 	int rank; MPI_Comm_rank(MPI_COMM_WORLD, &rank);
 	constexpr std::size_t n{16};
@@ -198,3 +199,15 @@ TEST(TestLocalAIRBSR, TestsInRuge_Stuben) {
 	auto R = local_air(*Absr, *S, split);
 }
 #endif
+
+TEST(UpwindAdvection, TestsInRuge_Stuben) {
+	constexpr std::size_t n{100};
+	std::vector<int> grid;
+	grid.resize(1, n);
+	std::vector<double> stencil{{-1, 1, 0}};
+	auto A = par_stencil_grid(stencil.data(), grid.data(), 1);
+
+	ParAIRSolver ml;
+	ml.max_levels = 2;
+	ml.setup(A);
+}