diff --git a/aviary/core/aviary_group.py b/aviary/core/aviary_group.py
index c157ccdab4..84869f6789 100644
--- a/aviary/core/aviary_group.py
+++ b/aviary/core/aviary_group.py
@@ -9,8 +9,7 @@
 from dymos.utils.misc import _unspecified
 from openmdao.utils.mpi import MPI
 
-from aviary.core.post_mission_group import PostMissionGroup
-from aviary.core.pre_mission_group import PreMissionGroup
+from aviary.core.static_group import StaticGroup
 from aviary.interface.utils import set_warning_format
 from aviary.mission.energy_state_problem_configurator import EnergyStateProblemConfigurator
 from aviary.mission.solved_two_dof_problem_configurator import SolvedTwoDOFProblemConfigurator
@@ -70,7 +69,7 @@ class AviaryGroup(om.Group):
     def __init__(self, verbosity=None, **kwargs):
         super().__init__(**kwargs)
 
-        self.post_mission = PostMissionGroup()
+        self.post_mission = StaticGroup()
         self.verbosity = verbosity
         self.external_subsystems = []
         self.engine_models = []
@@ -206,6 +205,28 @@ def configure(self):
                     phase.indep_states.nonlinear_solver = om.NewtonSolver(solve_subsystems=True)
                     phase.indep_states.linear_solver = om.DirectSolver(rhs_checking=True)
 
+    def _override_verbosity(self, verbosity):
+        """
+        Overrides verbosity setting for this method.
+
+        Parameters
+        ----------
+        verbosity : int, Verbosity (optional)
+            Verbosity level requested for this method.
+
+        Returns
+        -------
+        Verbosity
+            New verbosity for this method.
+        """
+        if verbosity is not None:
+            # compatibility with being passed int for verbosity
+            verbosity = Verbosity(verbosity)
+        else:
+            verbosity = self.verbosity  # defaults to BRIEF
+
+        return verbosity
+
     def load_inputs(
         self,
         aircraft_data,
@@ -224,13 +245,7 @@ def load_inputs(
         This method is not strictly necessary; a user could also supply
         an AviaryValues object and/or phase_info dict of their own.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         # validate phase info modifier function
         if phase_info_modifier is not None:
@@ -339,17 +354,10 @@ def load_external_subsystems(self, external_subsystems: list = [], verbosity=Non
         ----------
         external_subsystems : list of SubsystemBuilders
             List of all external subsystems to be added.
-
         verbosity : int, Verbosity (optional)
-            Sets the printout level for the entire off-design problem that is ran.
+            Verbosity level for this API call.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         for subsystem in external_subsystems:
             if not isinstance(subsystem, SubsystemBuilder) and verbosity >= verbosity.BRIEF:
@@ -370,13 +378,7 @@ def check_and_preprocess_inputs(self, verbosity=None):
         This method checks the user-supplied input values for any potential problems
         and preprocesses the inputs to prepare them for use in the Aviary problem.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         aviary_inputs = self.aviary_inputs
         # Target_distance verification for all phases
@@ -559,7 +561,7 @@ def add_pre_mission_systems(self, verbosity=None):
 
         A user can override this method with their own pre-mission systems as desired.
         """
-        pre_mission = PreMissionGroup()
+        pre_mission = StaticGroup()
         all_subsystem_options = self.pre_mission_info.get('subsystem_options', {})
 
         self.add_subsystem(
@@ -569,7 +571,7 @@ def add_pre_mission_systems(self, verbosity=None):
             promotes_outputs=['aircraft:*', 'mission:*'],
         )
 
-        # TODO temporary until way to merge PreMissionGroup and CorePreMission group is found
+        # TODO temporary until way to merge StaticGroup and CorePreMission group is found
         core_subsystems = self.subsystems[0:5]
 
         # Propulsion isn't included in core pre-mission group to avoid override step in
@@ -715,13 +717,7 @@ def add_phases(self, parallel_phases=True, verbosity=None, comm=None):
         -------
         traj: The Dymos Trajectory object containing the added mission phases.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.phase_info_modifier is not None:
             self.mission_info, self.post_mission_info = self.phase_info_modifier(
@@ -824,13 +820,7 @@ def add_post_mission_systems(self, verbosity=None):
 
         A user can override this with their own postmission systems.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         post_mission = self.post_mission
         self.add_subsystem(
@@ -1111,13 +1101,7 @@ def link_phases(self, verbosity=None, comm=None):
         If a variable is common to two phases, it can be linked via a direct connection or a
         constraint.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity override for
-        # just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         self._add_bus_variables_and_connect()
         self._connect_mission_bus_variables()
@@ -1486,13 +1470,7 @@ def add_design_variables(self, problem_type: ProblemType = None, verbosity=None)
         In all cases, a design variable is added for the final cruise mass of the aircraft, with no
         upper bound, and a residual mass constraint is added to ensure that the mass balances.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         all_subsystems = self.subsystems
 
@@ -1641,13 +1619,7 @@ def set_initial_guesses(self, parent_prob=None, parent_prefix='', verbosity=None
         if not hasattr(self, 'traj'):
             return
 
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         target_prob = self
         if parent_prob is not None and parent_prefix != '':
diff --git a/aviary/core/aviary_problem.py b/aviary/core/aviary_problem.py
index c03c32afdf..e38f82714c 100644
--- a/aviary/core/aviary_problem.py
+++ b/aviary/core/aviary_problem.py
@@ -121,6 +121,28 @@ def __init__(
         #      problems don't have a consistent variable path to check the inputs later on
         self.generate_payload_range = False
 
+    def _override_verbosity(self, verbosity):
+        """
+        Overrides verbosity setting for this method.
+
+        Parameters
+        ----------
+        verbosity : int, Verbosity (optional)
+            Verbosity level requested for this method.
+
+        Returns
+        -------
+        Verbosity
+            New verbosity for this method.
+        """
+        if verbosity is not None:
+            # compatibility with being passed int for verbosity
+            verbosity = Verbosity(verbosity)
+        else:
+            verbosity = self.verbosity  # defaults to BRIEF
+
+        return verbosity
+
     def load_inputs(
         self,
         aircraft_data,
@@ -166,11 +188,7 @@ def load_inputs(
         # We haven't read the input data yet, we don't know what desired run verbosity is
         # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
         # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # usually None
+        verbosity = self._override_verbosity(verbosity)
 
         if meta_data is not None:
             # Support for custom meta_data set.
@@ -215,13 +233,7 @@ def load_external_subsystems(self, external_subsystems: list = [], verbosity=Non
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -277,13 +289,7 @@ def add_aviary_group(
         ValueError
             If ``problem_type`` is not ``ProblemType.MULTI_MISSION``.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type is not ProblemType.MULTI_MISSION:
             ValueError(
@@ -330,13 +336,7 @@ def check_and_preprocess_inputs(self, verbosity=None):
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -368,13 +368,7 @@ def add_pre_mission_systems(self, verbosity=None):
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -407,13 +401,7 @@ def add_phases(
         dm.Trajectory
             The Dymos Trajectory object containing the added mission phases.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -461,13 +449,7 @@ def add_post_mission_systems(self, verbosity=None):
             Controls the level of terminal output for this method. If None,
             uses the problem-level verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -499,13 +481,7 @@ def link_phases(self, verbosity=None):
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -537,13 +513,7 @@ def add_driver(self, optimizer='IPOPT', use_coloring=True, max_iter=50, verbosit
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         # Set defaults for optimizer, use_coloring and max_iter
         if optimizer is None:
@@ -682,13 +652,7 @@ def add_design_variables(self, verbosity=None):
         In all cases, a design variable is added for the final cruise mass of the aircraft, with no
         upper bound, and a residual mass constraint is added to ensure that the mass balances.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -725,13 +689,7 @@ def add_objective(self, objective_type=None, ref=None, verbosity=None):
         ValueError
             If an invalid ``objective_type`` or ``problem_type`` is provided.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         # This isn't really a fuel objective, it's a hybrid or compound objective
         self.model.add_subsystem(
@@ -1042,9 +1000,8 @@ def add_composite_objective(self, *args, ref: float = None):
         # weighted_str looks like:  'model1_fuelburn*0.67*0.5 + model1_gross_mass*0.33*0.5 + model2_fuelburn*0.67*0.5 + model2_gross_mass*0.33*0.5'
 
         kwargs = {}
-        if version.parse(openmdao.__version__) >= version.parse('3.40'):
-            # We can get the correct unit from the source. This prevents a warning.
-            kwargs = {k: {'units_by_conn': True} for k in obj_inputs}
+        # We can get the correct unit from the source. This prevents a warning.
+        kwargs = {k: {'units_by_conn': True} for k in obj_inputs}
 
         # adding composite execComp to super problem
         self.model.add_subsystem(
@@ -1148,13 +1105,7 @@ def build_model(self, verbosity=None):
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -1257,13 +1208,7 @@ def set_initial_guesses(self, parent_prob=None, parent_prefix='', verbosity=None
             Controls the level of terminal output for this method. If None, uses the problem-level
             verbosity.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if self.problem_type == ProblemType.MULTI_MISSION:
             for name, group in self.aviary_groups_dict.items():
@@ -1316,13 +1261,7 @@ def run_aviary_problem(
         real_time_plotting : bool, optional
             If True, enables real-time plotting of the optimization progress.
         """
-        # `self.verbosity` is "true" verbosity for entire run. `verbosity` is verbosity
-        # override for just this method
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if (
             verbosity >= Verbosity.VERBOSE or real_time_plotting
@@ -1492,12 +1431,7 @@ def run_off_design_mission(
         UserWarning
             If ``problem_type`` is ``SIZING``, or if both ``fill_cargo`` and ``fill_fuel`` are True.
         """
-        # For off-design missions, provided verbosity will be used for all L2 method calls
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         # accept str for problem type
         problem_type = ProblemType(problem_type)
@@ -1735,12 +1669,7 @@ def run_payload_range(self, verbosity=None):
         Currently only supported for the energy state equations of motion. Reserve fuel is not yet
         accounted for in the analysis.
         """
-        # For off-design missions, provided verbosity will be used for all L2 method calls
-        if verbosity is not None:
-            # compatibility with being passed int for verbosity
-            verbosity = Verbosity(verbosity)
-        else:
-            verbosity = self.verbosity  # defaults to BRIEF
+        verbosity = self._override_verbosity(verbosity)
 
         if not self.result.success and verbosity > Verbosity.QUIET:
             warnings.warn(
diff --git a/aviary/core/post_mission_group.py b/aviary/core/post_mission_group.py
deleted file mode 100644
index 48d5895f42..0000000000
--- a/aviary/core/post_mission_group.py
+++ /dev/null
@@ -1,23 +0,0 @@
-import openmdao
-import openmdao.api as om
-from packaging import version
-
-from aviary.utils.functions import promote_aircraft_and_mission_vars
-
-use_new_openmdao_syntax = version.parse(openmdao.__version__) >= version.parse('3.28')
-
-
-class PostMissionGroup(om.Group):
-    """OpenMDAO group that holds all post-mission systems."""
-
-    def setup(self, **kwargs):
-        if use_new_openmdao_syntax:
-            # rely on openMDAO's auto-ordering for this group
-            self.options['auto_order'] = True
-
-    def configure(self):
-        """
-        Configure this group for post-mission.
-        Promote aircraft and mission variables.
-        """
-        promote_aircraft_and_mission_vars(self)
diff --git a/aviary/core/pre_mission_group.py b/aviary/core/pre_mission_group.py
deleted file mode 100644
index 0122d37b95..0000000000
--- a/aviary/core/pre_mission_group.py
+++ /dev/null
@@ -1,24 +0,0 @@
-import openmdao.api as om
-
-from aviary.utils.functions import promote_aircraft_and_mission_vars
-from aviary.variable_info.functions import override_aviary_vars
-
-
-class PreMissionGroup(om.Group):
-    """OpenMDAO group that holds all pre-mission systems."""
-
-    def configure(self):
-        """
-        Configure this group for pre-mission.
-        Promote aircraft and mission variables.
-        Override output aviary variables.
-        """
-        external_outputs = promote_aircraft_and_mission_vars(self)
-
-        pre_mission = self.core_subsystems
-        override_aviary_vars(
-            pre_mission,
-            pre_mission.options['aviary_options'],
-            external_overrides=external_outputs,
-            code_origin_overrides=pre_mission.code_origin_overrides,
-        )
diff --git a/aviary/core/static_group.py b/aviary/core/static_group.py
new file mode 100644
index 0000000000..5ba7bd705e
--- /dev/null
+++ b/aviary/core/static_group.py
@@ -0,0 +1,34 @@
+import openmdao.api as om
+
+from aviary.utils.functions import promote_aircraft_and_mission_vars
+from aviary.variable_info.functions import override_aviary_vars
+
+
+class StaticGroup(om.Group):
+    """Aviary top-level group that is not a dynamic mission.
+
+    This class is used for top pre_mission and post_mission groups.
+    """
+
+    def setup(self, **kwargs):
+        self.options['auto_order'] = True
+
+    def configure(self):
+        """
+        Configure this group for pre or post mission.
+        Promote aircraft and mission variables.
+        Override output aviary variables.
+        """
+        external_outputs = promote_aircraft_and_mission_vars(self)
+
+        if not hasattr(self, 'core_subsystems'):
+            # TODO Post mission doesn't support core subsystems yet.
+            return
+
+        core_subs = self.core_subsystems
+        override_aviary_vars(
+            core_subs,
+            core_subs.options['aviary_options'],
+            external_overrides=external_outputs,
+            code_origin_overrides=core_subs.code_origin_overrides,
+        )
diff --git a/aviary/docs/examples_unreviewed/deconstructed_example.ipynb b/aviary/docs/examples_unreviewed/deconstructed_example.ipynb
index 10df31ffcc..a333b6a82e 100644
--- a/aviary/docs/examples_unreviewed/deconstructed_example.ipynb
+++ b/aviary/docs/examples_unreviewed/deconstructed_example.ipynb
@@ -149,7 +149,7 @@
     "import openmdao.api as om\n",
     "\n",
     "import aviary.api as av\n",
-    "from aviary.core.pre_mission_group import PreMissionGroup\n",
+    "from aviary.core.static_group import StaticGroup\n",
     "from aviary.mission.flight_phase_builder import FlightPhaseOptions\n",
     "from aviary.mission.energy_state.ode.energy_state_ODE import EnergyStateODE\n",
     "from aviary.models.missions.energy_state_default import phase_info\n",
@@ -215,7 +215,7 @@
     "\n",
     "prob.model.add_subsystem(\n",
     "    'pre_mission',\n",
-    "    PreMissionGroup(),\n",
+    "    StaticGroup(),\n",
     "    promotes_inputs=['aircraft:*', 'mission:*'],\n",
     "    promotes_outputs=['aircraft:*', 'mission:*'],\n",
     ")\n",
@@ -1009,7 +1009,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.11"
+   "version": "3.12.3"
   }
  },
  "nbformat": 4,
diff --git a/aviary/mission/base_ode.py b/aviary/mission/base_ode.py
index 53cfdea8d6..f541ac7a7f 100644
--- a/aviary/mission/base_ode.py
+++ b/aviary/mission/base_ode.py
@@ -21,6 +21,12 @@ def configure(self):
 class BaseODE(om.Group):
     """The base class for all ODE components."""
 
+    def __init__(self, **kwargs):
+        super().__init__(**kwargs)
+
+        # Turn on for all ODE systems.
+        self.options['auto_order'] = True
+
     def initialize(self):
         self.options.declare('num_nodes', default=1, types=int)
         self.options.declare(
diff --git a/aviary/mission/energy_state/ode/energy_state_ODE.py b/aviary/mission/energy_state/ode/energy_state_ODE.py
index 1fff10a71e..31c05d8d08 100644
--- a/aviary/mission/energy_state/ode/energy_state_ODE.py
+++ b/aviary/mission/energy_state/ode/energy_state_ODE.py
@@ -59,6 +59,7 @@ def setup(self):
         throttle_enforcement = options['throttle_enforcement']
 
         sub1 = self.add_subsystem('solver_sub', om.Group(), promotes=['*'])
+        sub1.options['auto_order'] = True
 
         use_mission_solver = self.add_subsystems(solver_group=sub1)
 
@@ -175,5 +176,3 @@ def setup(self):
             sub1.linear_solver = om.DirectSolver(assemble_jac=True)
             sub1.nonlinear_solver.options['err_on_non_converge'] = True
             sub1.nonlinear_solver.options['iprint'] = print_level
-
-        self.options['auto_order'] = True
diff --git a/aviary/mission/solved_two_dof/ode/unsteady_solved_ode.py b/aviary/mission/solved_two_dof/ode/unsteady_solved_ode.py
index 59ccd9783b..4780b481ab 100644
--- a/aviary/mission/solved_two_dof/ode/unsteady_solved_ode.py
+++ b/aviary/mission/solved_two_dof/ode/unsteady_solved_ode.py
@@ -122,6 +122,7 @@ def setup(self):
         throttle_balance_group = self.add_subsystem(
             'throttle_balance_group', om.Group(), promotes=['*']
         )
+        throttle_balance_group.options['auto_order'] = True
 
         throttle_balance_comp = om.BalanceComp()
         throttle_balance_comp.add_balance(
diff --git a/aviary/mission/two_dof/ode/flight_ode.py b/aviary/mission/two_dof/ode/flight_ode.py
index 3b9535bdfc..ec10f9c3e0 100644
--- a/aviary/mission/two_dof/ode/flight_ode.py
+++ b/aviary/mission/two_dof/ode/flight_ode.py
@@ -33,7 +33,6 @@ def initialize(self):
         self.options.declare('EAS_target', desc='Targeted EAS in knots')
 
     def setup(self):
-        self.options['auto_order'] = True
         nn = self.options['num_nodes']
         aviary_options = self.options['aviary_options']
         subsystems = self.options['subsystems']
diff --git a/aviary/mission/two_dof/ode/flight_path_ode.py b/aviary/mission/two_dof/ode/flight_path_ode.py
index 3e4b7fc3f5..17c8c7c4a7 100644
--- a/aviary/mission/two_dof/ode/flight_path_ode.py
+++ b/aviary/mission/two_dof/ode/flight_path_ode.py
@@ -38,7 +38,6 @@ def initialize(self):
         )
 
     def setup(self):
-        self.options['auto_order'] = True
         nn = self.options['num_nodes']
         aviary_options = self.options['aviary_options']
         alpha_mode = self.options['alpha_mode']
diff --git a/aviary/mission/two_dof/ode/test/test_flight_ode.py b/aviary/mission/two_dof/ode/test/test_flight_ode.py
index d854e77642..2fdcd8a372 100644
--- a/aviary/mission/two_dof/ode/test/test_flight_ode.py
+++ b/aviary/mission/two_dof/ode/test/test_flight_ode.py
@@ -156,10 +156,6 @@ def setUp(self):
 
         setup_model_options(self.prob, aviary_options)
 
-    @unittest.skipIf(
-        version.parse(openmdao.__version__) < version.parse('3.26'),
-        'Skipping due to OpenMDAO version being too low (<3.26)',
-    )
     def test_high_alt(self):
         # Test descent above 10k ft with Mach under and over the EAS limit
         self.sys.options['num_nodes'] = 2
diff --git a/aviary/mission/two_dof/ode/test/test_landing_ode.py b/aviary/mission/two_dof/ode/test/test_landing_ode.py
index 8503b80fd0..2a802c1f02 100644
--- a/aviary/mission/two_dof/ode/test/test_landing_ode.py
+++ b/aviary/mission/two_dof/ode/test/test_landing_ode.py
@@ -32,10 +32,6 @@ def setUp(self):
         setup_model_options(self.prob, options)
         self.prob.model.set_input_defaults(Mission.Landing.AIRPORT_ALTITUDE, 0, units='ft')
 
-    @unittest.skipIf(
-        version.parse(openmdao.__version__) < version.parse('3.26'),
-        'Skipping due to OpenMDAO version being too low (<3.26)',
-    )
     def test_dland(self):
         self.prob.setup(check=False, force_alloc_complex=True)
 
diff --git a/aviary/mission/two_dof/ode/test/test_taxi_ode.py b/aviary/mission/two_dof/ode/test/test_taxi_ode.py
index 79c2f0d524..2535215b5e 100644
--- a/aviary/mission/two_dof/ode/test/test_taxi_ode.py
+++ b/aviary/mission/two_dof/ode/test/test_taxi_ode.py
@@ -38,10 +38,6 @@ def setUp(self):
             0.0,
         )
 
-    @unittest.skipIf(
-        version.parse(openmdao.__version__) < version.parse('3.26'),
-        'Skipping due to OpenMDAO version being too low (<3.26)',
-    )
     def test_taxi(self):
         self.prob.setup(check=False, force_alloc_complex=True)
 
diff --git a/aviary/mission/two_dof/test/test_promotion.py b/aviary/mission/two_dof/test/test_promotion.py
index 99e64ff0f1..23c7a155d4 100644
--- a/aviary/mission/two_dof/test/test_promotion.py
+++ b/aviary/mission/two_dof/test/test_promotion.py
@@ -1,3 +1,4 @@
+from copy import deepcopy
 import unittest
 
 import openmdao.api as om
@@ -16,9 +17,11 @@ class Test2DOFMissionPromotion(unittest.TestCase):
     def test_promotion(self):
         prob = AviaryProblem()
 
+        local_phase_info = deepcopy(phase_info)
+
         prob.load_inputs(
             'validation_cases/validation_data/test_models/aircraft_for_bench_GwGm.csv',
-            phase_info,
+            local_phase_info,
             verbosity=0,
         )
 
diff --git a/aviary/subsystems/atmosphere/test/test_atmosphere.py b/aviary/subsystems/atmosphere/test/test_atmosphere.py
index aa0939363d..ca7ca04ba1 100644
--- a/aviary/subsystems/atmosphere/test/test_atmosphere.py
+++ b/aviary/subsystems/atmosphere/test/test_atmosphere.py
@@ -318,14 +318,12 @@ def test_case1(self):
             with self.subTest(var=var_name):
                 assert_near_equal(self.prob.get_val(var_name, units=units), expected, tol)
 
-        # inHg60 is a newer unit in OpenMDAO so we'll do this check only of that newer version is installed
-        if Version(openmdao.__version__) >= Version('3.42.0'):
-            with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
-                assert_near_equal(
-                    self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
-                    expected_pressure,
-                    tol,
-                )
+        with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
+            assert_near_equal(
+                self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
+                expected_pressure,
+                tol,
+            )
 
         partial_data = self.prob.check_partials(out_stream=None, method='cs')
 
@@ -400,13 +398,12 @@ def test_case1(self):
             with self.subTest(var=var_name):
                 assert_near_equal(self.prob.get_val(var_name, units=units), expected, tol)
 
-        if Version(openmdao.__version__) >= Version('3.42.0'):
-            with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
-                assert_near_equal(
-                    self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
-                    expected_pressure,
-                    tol,
-                )
+        with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
+            assert_near_equal(
+                self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
+                expected_pressure,
+                tol,
+            )
 
         partial_data = self.prob.check_partials(out_stream=None, method='cs')
 
@@ -481,13 +478,12 @@ def test_case1(self):
             with self.subTest(var=var_name):
                 assert_near_equal(self.prob.get_val(var_name, units=units), expected, tol)
 
-        if Version(openmdao.__version__) >= Version('3.42.0'):
-            with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
-                assert_near_equal(
-                    self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
-                    expected_pressure,
-                    tol,
-                )
+        with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
+            assert_near_equal(
+                self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
+                expected_pressure,
+                tol,
+            )
 
         partial_data = self.prob.check_partials(out_stream=None, method='cs')
 
@@ -562,13 +558,12 @@ def test_case1(self):
             with self.subTest(var=var_name):
                 assert_near_equal(self.prob.get_val(var_name, units=units), expected, tol)
 
-        if Version(openmdao.__version__) >= Version('3.42.0'):
-            with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
-                assert_near_equal(
-                    self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
-                    expected_pressure,
-                    tol,
-                )
+        with self.subTest(var=Dynamic.Atmosphere.STATIC_PRESSURE):
+            assert_near_equal(
+                self.prob.get_val(Dynamic.Atmosphere.STATIC_PRESSURE, units='inHg60'),
+                expected_pressure,
+                tol,
+            )
 
         partial_data = self.prob.check_partials(out_stream=None, method='cs')
 
diff --git a/aviary/subsystems/premission.py b/aviary/subsystems/premission.py
index 09e4f43015..512e408f1d 100644
--- a/aviary/subsystems/premission.py
+++ b/aviary/subsystems/premission.py
@@ -6,8 +6,6 @@
 from aviary.variable_info.functions import override_aviary_vars
 from aviary.variable_info.variable_meta_data import CoreMetaData
 
-use_new_openmdao_syntax = version.parse(openmdao.__version__) >= version.parse('3.28')
-
 
 class CorePreMission(om.Group):
     """
@@ -38,9 +36,8 @@ def initialize(self):
         )
 
     def setup(self, **kwargs):
-        if use_new_openmdao_syntax:
-            # rely on openMDAO's auto-ordering for this group
-            self.options['auto_order'] = True
+        # rely on openMDAO's auto-ordering for this group
+        self.options['auto_order'] = True
 
         aviary_options = self.options['aviary_options']
         subsystems = self.options['subsystems']
diff --git a/aviary/subsystems/propulsion/test/test_propulsion_mission.py b/aviary/subsystems/propulsion/test/test_propulsion_mission.py
index 0faddea21b..c53336b6f4 100644
--- a/aviary/subsystems/propulsion/test/test_propulsion_mission.py
+++ b/aviary/subsystems/propulsion/test/test_propulsion_mission.py
@@ -29,10 +29,6 @@ def setUp(self):
         self.options = AviaryValues()
         self.options.set_val(Settings.VERBOSITY, 0)
 
-    @unittest.skipIf(
-        version.parse(openmdao.__version__) < version.parse('3.26'),
-        'Skipping due to OpenMDAO version being too low (<3.26)',
-    )
     def test_case_1(self):
         # 'clean' test using GASP-derived engine deck
         nn = 20
diff --git a/aviary/validation_cases/benchmark_tests/test_battery_in_a_mission.py b/aviary/validation_cases/benchmark_tests/test_battery_in_a_mission.py
index cfcff344e7..4d568d0ef5 100644
--- a/aviary/validation_cases/benchmark_tests/test_battery_in_a_mission.py
+++ b/aviary/validation_cases/benchmark_tests/test_battery_in_a_mission.py
@@ -101,8 +101,8 @@ def test_subsystems_in_a_mission(self):
             f'traj.cruise2.timeseries.{av.Dynamic.Vehicle.CUMULATIVE_ELECTRIC_ENERGY_USED}'
         )
         expected_scalar_values = {
-            cumulative_energy_var: (38.46816871, 'kW*h'),
-            av.Mission.FUEL_MASS: (1249.64650547, 'lbm'),
+            cumulative_energy_var: (38.61409156, 'kW*h'),
+            av.Mission.FUEL_MASS: (1254.14061154, 'lbm'),
         }
 
         for var_name, (expected, units) in expected_scalar_values.items():
@@ -119,51 +119,51 @@ def test_subsystems_in_a_mission(self):
         expected_soc_values = {
             soc_cruise1_var: (
                 [
-                    0.9999957806265609,
-                    0.9877977965127587,
-                    0.9709679386644526,
-                    0.9656415564989798,
-                    0.9656415564989798,
-                    0.9407334200010511,
-                    0.906368905403873,
-                    0.8954935308182879,
-                    0.8954935308182879,
-                    0.8658878715348804,
-                    0.8250432325811342,
-                    0.8121172826623315,
-                    0.8121172826623315,
-                    0.7872227709968601,
-                    0.752877052113554,
-                    0.7420076253955674,
-                    0.7420076253955674,
-                    0.729820851948888,
-                    0.7130064610124855,
-                    0.7076849737044318,
+                    0.99999578,
+                    0.98775148,
+                    0.97085772,
+                    0.96551112,
+                    0.96551112,
+                    0.94050842,
+                    0.90601345,
+                    0.8950968,
+                    0.8950968,
+                    0.86537877,
+                    0.82437912,
+                    0.81140412,
+                    0.81140412,
+                    0.78641514,
+                    0.75193911,
+                    0.74102844,
+                    0.74102844,
+                    0.72879544,
+                    0.71191726,
+                    0.70657558,
                 ],
                 None,
             ),
             soc_cruise2_var: (
                 [
-                    0.7076849737044318,
-                    0.6954996910206249,
-                    0.6786873568305393,
-                    0.6733665204268243,
-                    0.6733665204268243,
-                    0.6484843167073028,
-                    0.6141555768684874,
-                    0.6032915231366659,
-                    0.6032915231366659,
-                    0.5737166802223987,
-                    0.532914551421322,
-                    0.5200020533696793,
-                    0.5200020533696793,
-                    0.49513344752347366,
-                    0.460823466208866,
-                    0.44996534857628184,
-                    0.44996534857628184,
-                    0.4377912370406455,
-                    0.4209942619176692,
-                    0.41567827333310314,
+                    0.70657558,
+                    0.69434408,
+                    0.67746797,
+                    0.67212695,
+                    0.67212695,
+                    0.64715037,
+                    0.61269144,
+                    0.60178619,
+                    0.60178619,
+                    0.5720992,
+                    0.53114236,
+                    0.51818091,
+                    0.51818091,
+                    0.49321803,
+                    0.45877799,
+                    0.44787871,
+                    0.44787871,
+                    0.43565848,
+                    0.41879792,
+                    0.41346182,
                 ],
                 None,
             ),
diff --git a/aviary/validation_cases/benchmark_tests/test_subsystems_within_a_mission.py b/aviary/validation_cases/benchmark_tests/test_subsystems_within_a_mission.py
index b0bc9bf5d1..1c7c9f23c9 100644
--- a/aviary/validation_cases/benchmark_tests/test_subsystems_within_a_mission.py
+++ b/aviary/validation_cases/benchmark_tests/test_subsystems_within_a_mission.py
@@ -1,3 +1,4 @@
+from copy import deepcopy
 import unittest
 
 import numpy as np
@@ -127,9 +128,11 @@ def test_subsystems_in_a_mission_energy_state(self):
     def test_subsystems_in_a_mission_2dof(self):
         prob = AviaryProblem(verbosity=0)
 
+        local_phase_info = deepcopy(two_dof_phase_info)
+
         prob.load_inputs(
             'validation_cases/validation_data/test_models/aircraft_for_bench_GwGm.csv',
-            two_dof_phase_info,
+            local_phase_info,
         )
 
         prob.load_external_subsystems(