aeromaps.models.air_transport.aircraft_fleet_and_operations.load_factor.load_factor

load_factor

Module for computing aircraft load factor evolution

LoadFactor

LoadFactor(name='load_factor', *args, **kwargs)

Bases: AeroMAPSModel

Model for computing aircraft load factor evolution based on user's inputs.

Parameters:

Name	Type	Description	Default
name	str	Name of the model instance ('load_factor' by default).	'load_factor'

Source code in aeromaps/models/air_transport/aircraft_fleet_and_operations/load_factor/load_factor.py

def __init__(self, name="load_factor", *args, **kwargs):
    super().__init__(name=name, *args, **kwargs)

compute

compute(load_factor_end_year, covid_load_factor_2020, rpk, ask_init)

Execute the computation of aircraft load factor.

Historical load factor values are computed from provided RPK and historical ASK, initializes the 2019 load factor as a baseline, then projects load factor forward to end_year using a quadratic model. The 2020 value is overwritten with a Covid-19-specific value.

Parameters:

Name	Type	Description	Default
load_factor_end_year	float	Value of mean aircraft load factor in the considered end year [%].	required
covid_load_factor_2020	float	Load factor due to Covid-19 for the start_year [%].	required
rpk	Series	Total number of Revenue Passenger Kilometer (RPK).	required
ask_init	Series	Historical number of Available Seat Kilometer (ASK) over 2000-2019 [ASK].	required

Returns:

Type	Description
load_factor	Mean aircraft load factor for each year of the model period [%].

Source code in aeromaps/models/air_transport/aircraft_fleet_and_operations/load_factor/load_factor.py

def compute(
    self,
    load_factor_end_year: float,
    covid_load_factor_2020: float,
    rpk: pd.Series,
    ask_init: pd.Series,
) -> pd.Series:
    """Execute the computation of aircraft load factor.

    Historical load factor values are computed from provided RPK and
    historical ASK, initializes the 2019 load factor as a baseline, then
    projects load factor forward to `end_year` using a quadratic model.
    The 2020 value is overwritten with a Covid-19-specific value.

    Parameters
    ----------
    load_factor_end_year
        Value of mean aircraft load factor in the considered end year [%].
    covid_load_factor_2020
        Load factor due to Covid-19 for the start_year [%].
    rpk
        Total number of Revenue Passenger Kilometer (RPK).
    ask_init
        Historical number of Available Seat Kilometer (ASK) over 2000-2019 [ASK].

    Returns
    -------
    load_factor
        Mean aircraft load factor for each year of the model period [%].
    """
    for k in range(self.historic_start_year, self.prospection_start_year):
        self.df.loc[k, "load_factor"] = rpk.loc[k] / ask_init.loc[k] * 100

    # Initialization for load factor
    load_factor_2019 = self.df.loc[2019, "load_factor"]

    # Parameters for the model
    a, b = self.parameters_load_factor_model(
        self.end_year, load_factor_2019, load_factor_end_year
    )

    for k in range(self.prospection_start_year, self.end_year + 1):
        self.df.loc[k, "load_factor"] = a * (k - 2019) ** 2 + b * (k - 2019) + load_factor_2019

    # Covid-19 : à refaire proprement
    self.df.loc[2020, "load_factor"] = covid_load_factor_2020

    load_factor = self.df["load_factor"]

    return load_factor

parameters_load_factor_model staticmethod

parameters_load_factor_model(end_year, load_factor_2019, load_factor_end_year)

Compute the parameters of the quadratic model for load factor evolution.

Parameters:

Name	Type	Description	Default
end_year		Year at which the target load factor is reached [yr]	required
load_factor_2019		Load factor in 2019 [%]	required
load_factor_end_year		Target load factor in end_year [%]	required

Returns:

Type	Description
a	Second order parameter of the quadratic model
b	First order parameter of the quadratic model

Source code in aeromaps/models/air_transport/aircraft_fleet_and_operations/load_factor/load_factor.py

@staticmethod
def parameters_load_factor_model(end_year, load_factor_2019, load_factor_end_year):
    """
    Compute the parameters of the quadratic model for load factor evolution.

    Parameters
    ----------
    end_year
        Year at which the target load factor is reached [yr]
    load_factor_2019
        Load factor in 2019 [%]
    load_factor_end_year
        Target load factor in end_year [%]

    Returns
    -------
    a
        Second order parameter of the quadratic model
    b
        First order parameter of the quadratic model

    """
    # Calculate via derivative : 2ax+b
    derivative = 2 * (-5.62003082e-05) * 31 + 3.59670410e-03
    a = (
        -(load_factor_end_year - load_factor_2019 - derivative * (end_year - 2019))
        / (end_year - 2019) ** 2
    )
    b = derivative - 2 * a * (end_year - 2019)
    return [a, b]