diff --git a/aviary/subsystems/aerodynamics/gasp_based/test/test_gasp_aero_coeffs.py b/aviary/subsystems/aerodynamics/gasp_based/test/test_gasp_aero_coeffs.py
index ca205cffa2..080c3b29b1 100644
--- a/aviary/subsystems/aerodynamics/gasp_based/test/test_gasp_aero_coeffs.py
+++ b/aviary/subsystems/aerodynamics/gasp_based/test/test_gasp_aero_coeffs.py
@@ -2,6 +2,7 @@
 
 import openmdao.api as om
 from openmdao.utils.assert_utils import assert_check_partials, assert_near_equal
+from openmdao.utils.testing_utils import use_tempdirs
 
 from aviary.subsystems.aerodynamics.gasp_based.gasp_aero_coeffs import (
     AeroFormfactors,
@@ -15,6 +16,7 @@
 tol = 1e-8
 
 
+@use_tempdirs
 class TestAeroCoeffs(unittest.TestCase):
     def test_aero_coeffs(self):
         aero_coeffs = AeroFormfactors()
@@ -87,6 +89,7 @@ def test_multiengine(self):
         assert_check_partials(partial_data, atol=1e-12, rtol=1e-14)
 
 
+@use_tempdirs
 class FormFactorTest(unittest.TestCase):
     """Test fuselage form factor computation and SIWB computation."""
 
@@ -112,6 +115,7 @@ def test_case1(self):
         assert_check_partials(partial_data, atol=1e-11, rtol=1e-11)
 
 
+@use_tempdirs
 class BWBFormFactorTest(unittest.TestCase):
     """Test fuselage form factor computation and SIWB computation"""
 
diff --git a/aviary/subsystems/aerodynamics/gasp_based/test/test_gaspaero.py b/aviary/subsystems/aerodynamics/gasp_based/test/test_gaspaero.py
index cbbb15e67c..8fccb92f3d 100644
--- a/aviary/subsystems/aerodynamics/gasp_based/test/test_gaspaero.py
+++ b/aviary/subsystems/aerodynamics/gasp_based/test/test_gaspaero.py
@@ -1969,6 +1969,3 @@ def test_case1(self):
 
 if __name__ == '__main__':
     unittest.main()
-    test = AeroGeomTest()
-    # test.test_case1()
-    test.test_case_multiengine()
diff --git a/aviary/utils/preprocessors.py b/aviary/utils/preprocessors.py
index 9d86203a11..c5dda38dba 100644
--- a/aviary/utils/preprocessors.py
+++ b/aviary/utils/preprocessors.py
@@ -1199,5 +1199,9 @@ def _get_engine_variables():
     for item in get_names_from_hierarchy(Aircraft.Engine):
         yield item
 
+    excluded_names = [
+        Aircraft.Nacelle.TOTAL_WETTED_AREA,
+    ]
     for item in get_names_from_hierarchy(Aircraft.Nacelle):
-        yield item
+        if item not in excluded_names:
+            yield item
diff --git a/aviary/validation_cases/validation_data/test_data/bwb300_baseline_FLOPS_data.py b/aviary/validation_cases/validation_data/test_data/bwb300_baseline_FLOPS_data.py
index d9dcad79b7..7ad6da3310 100644
--- a/aviary/validation_cases/validation_data/test_data/bwb300_baseline_FLOPS_data.py
+++ b/aviary/validation_cases/validation_data/test_data/bwb300_baseline_FLOPS_data.py
@@ -368,7 +368,7 @@
 outputs.set_val(Aircraft.Nacelle.MASS, 0.0, 'lbm')  # WNAC
 nacelle_wetted_area = np.array([613.74211034217353])  # SWET(5)
 outputs.set_val(Aircraft.Nacelle.WETTED_AREA, nacelle_wetted_area, 'ft**2')
-outputs.set_val(Aircraft.Nacelle.TOTAL_WETTED_AREA, 2 * nacelle_wetted_area, 'ft**2')
+outputs.set_val(Aircraft.Nacelle.TOTAL_WETTED_AREA, 2 * nacelle_wetted_area[0], 'ft**2')
 
 outputs.set_val(Aircraft.Paint.MASS, 0.0, 'lbm')  # WPAINT, WTPNT
 
diff --git a/aviary/validation_cases/validation_data/test_data/bwb_detailed_FLOPS_data.py b/aviary/validation_cases/validation_data/test_data/bwb_detailed_FLOPS_data.py
index 6866f54a80..1cbd9f28da 100644
--- a/aviary/validation_cases/validation_data/test_data/bwb_detailed_FLOPS_data.py
+++ b/aviary/validation_cases/validation_data/test_data/bwb_detailed_FLOPS_data.py
@@ -366,7 +366,7 @@
 outputs.set_val(Aircraft.Nacelle.MASS, 0.0, 'lbm')  # WNAC
 nacelle_wetted_area = np.array([498.26822066])  # SWET(5)
 outputs.set_val(Aircraft.Nacelle.WETTED_AREA, nacelle_wetted_area, 'ft**2')
-outputs.set_val(Aircraft.Nacelle.TOTAL_WETTED_AREA, 3 * nacelle_wetted_area, 'ft**2')
+outputs.set_val(Aircraft.Nacelle.TOTAL_WETTED_AREA, 3 * nacelle_wetted_area[0], 'ft**2')
 
 outputs.set_val(Aircraft.Paint.MASS, 0.0, 'lbm')  # WPAINT, WTPNT
 
diff --git a/aviary/validation_cases/validation_data/test_data/bwb_simple_FLOPS_data.py b/aviary/validation_cases/validation_data/test_data/bwb_simple_FLOPS_data.py
index 184176d609..044b2f01a4 100644
--- a/aviary/validation_cases/validation_data/test_data/bwb_simple_FLOPS_data.py
+++ b/aviary/validation_cases/validation_data/test_data/bwb_simple_FLOPS_data.py
@@ -318,7 +318,7 @@
 outputs.set_val(Aircraft.Nacelle.MASS, 0.0, 'lbm')  # WNAC
 nacelle_wetted_area = np.array([498.26822066])  # SWET(5)
 outputs.set_val(Aircraft.Nacelle.WETTED_AREA, nacelle_wetted_area, 'ft**2')
-outputs.set_val(Aircraft.Nacelle.TOTAL_WETTED_AREA, 3 * nacelle_wetted_area, 'ft**2')
+outputs.set_val(Aircraft.Nacelle.TOTAL_WETTED_AREA, 3 * nacelle_wetted_area[0], 'ft**2')
 
 outputs.set_val(Aircraft.Paint.MASS, 0.0, 'lbm')  # WPAINT, WTPNT
 
diff --git a/aviary/validation_cases/validation_data/test_data/large_single_aisle_1_FLOPS_data.py b/aviary/validation_cases/validation_data/test_data/large_single_aisle_1_FLOPS_data.py
index 60c275555a..c7441edee7 100644
--- a/aviary/validation_cases/validation_data/test_data/large_single_aisle_1_FLOPS_data.py
+++ b/aviary/validation_cases/validation_data/test_data/large_single_aisle_1_FLOPS_data.py
@@ -329,7 +329,7 @@
 outputs.set_val(Aircraft.Nacelle.WETTED_AREA, nacelle_wetted_area, nacelle_wetted_area_units)
 
 outputs.set_val(
-    Aircraft.Nacelle.TOTAL_WETTED_AREA, 2 * nacelle_wetted_area, nacelle_wetted_area_units
+    Aircraft.Nacelle.TOTAL_WETTED_AREA, 2 * nacelle_wetted_area[0], nacelle_wetted_area_units
 )
 
 outputs.set_val(Aircraft.Paint.MASS, 306.2, 'lbm')
diff --git a/aviary/validation_cases/validation_data/test_data/large_single_aisle_2_detailwing_FLOPS_data.py b/aviary/validation_cases/validation_data/test_data/large_single_aisle_2_detailwing_FLOPS_data.py
index 738269ad3d..292de5202e 100644
--- a/aviary/validation_cases/validation_data/test_data/large_single_aisle_2_detailwing_FLOPS_data.py
+++ b/aviary/validation_cases/validation_data/test_data/large_single_aisle_2_detailwing_FLOPS_data.py
@@ -324,7 +324,7 @@
 nacelle_wetted_area_units = 'ft**2'
 outputs.set_val(Aircraft.Nacelle.WETTED_AREA, nacelle_wetted_area, nacelle_wetted_area_units)
 outputs.set_val(
-    Aircraft.Nacelle.TOTAL_WETTED_AREA, 2 * nacelle_wetted_area, nacelle_wetted_area_units
+    Aircraft.Nacelle.TOTAL_WETTED_AREA, 2 * nacelle_wetted_area[0], nacelle_wetted_area_units
 )
 
 outputs.set_val(Aircraft.Paint.MASS, 582.3, 'lbm')
diff --git a/aviary/validation_cases/validation_data/test_data/multi_engine_single_aisle_data.py b/aviary/validation_cases/validation_data/test_data/multi_engine_single_aisle_data.py
index 5321c2cbf9..a20315ac64 100644
--- a/aviary/validation_cases/validation_data/test_data/multi_engine_single_aisle_data.py
+++ b/aviary/validation_cases/validation_data/test_data/multi_engine_single_aisle_data.py
@@ -361,7 +361,7 @@
 
 outputs.set_val(
     Aircraft.Nacelle.TOTAL_WETTED_AREA,
-    2 * nacelle_wetted_area,
+    2 * nacelle_wetted_area[0],
     nacelle_wetted_area_units,
 )
 
diff --git a/aviary/variable_info/variable_meta_data.py b/aviary/variable_info/variable_meta_data.py
index 76f32adfbe..ec4b068497 100644
--- a/aviary/variable_info/variable_meta_data.py
+++ b/aviary/variable_info/variable_meta_data.py
@@ -4423,7 +4423,6 @@
     units='ft**2',
     desc='total nacelles wetted area',
     default_value=0.0,
-    multivalue=True,
 )
 
 add_meta_data(