# This file is part of FAST-OAD_CS23-HE : A framework for rapid Overall Aircraft Design of Hybrid
# Electric Aircraft.
# Copyright (C) 2025 ISAE-SUPAERO
import numpy as np
import openmdao.api as om
[docs]
class LCCMaintenanceMiscellaneousCost(om.ExplicitComponent):
"""
Computation of the annual miscellaneous cost of the aircraft. The calculation is adjusted
based on the cost rate from https://www.guardianjet.com/jet-aircraft-online-tools and
https://planephd.com/wizard.
"""
[docs]
def setup(self):
self.add_input(
name="data:TLAR:flight_hours_per_year",
val=283.2,
units="h",
desc="Expected number of hours flown per year",
)
self.add_input(
"data:weight:aircraft:OWE",
units="kg",
val=np.nan,
)
self.add_output(
"data:cost:operation:miscellaneous_cost",
val=200.0,
units="USD/yr",
desc="Annual airframe maintenance material cost per aircraft",
)
self.declare_partials(of="*", wrt="*", method="exact")
[docs]
def compute(self, inputs, outputs, discrete_inputs=None, discrete_outputs=None):
owe_clipped = np.clip(inputs["data:weight:aircraft:OWE"], 500.0, None)
outputs["data:cost:operation:miscellaneous_cost"] = inputs[
"data:TLAR:flight_hours_per_year"
] * (-22.8 + 0.0459 * owe_clipped)
[docs]
def compute_partials(self, inputs, partials, discrete_inputs=None):
owe_clipped = np.clip(inputs["data:weight:aircraft:OWE"], 500.0, None)
partials["data:cost:operation:miscellaneous_cost", "data:TLAR:flight_hours_per_year"] = (
-22.8 + 0.0459 * owe_clipped
)
partials["data:cost:operation:miscellaneous_cost", "data:weight:aircraft:OWE"] = np.where(
inputs["data:weight:aircraft:OWE"] == owe_clipped,
0.0459 * inputs["data:TLAR:flight_hours_per_year"],
1e-6,
)