The aircraft configuration is determined based on the data from the TLARs. For this, the information about the possible propulsion types, mounting positions and number of engines are used.
!!! note
If no matching radii of gyration are found, a critical message is shown and the values for the radii are set to the ones for a jet with two wing mounted engines to keep the workflow running. It is the user's responsability to check the validity of the chosen calculation methods and the results.
#### 2. Using the LTH Tables (*Luftfahrttechnisches Handbuch*)
The LTH provides tabulated values and empirical methods specific to various aircraft configurations. These tables account for typical mass distributions and structural layouts. They are more accurate than Raymer’s approach but require knowledge of the specific aircraft class and design. The `calculate_inertia_by_lth_method` function is tailored specifically for conventional tube-and-wing configurations. This method uses aircraft mass properties like the OEM, the payload mass ($m_{payload}$) and the fuel mass ($m_{fuel}$) and geometric dimensions such as wing span $b$ and fuselage length $l$. All cross-product terms ($I_{xy}$, $I_{xz}$, etc.) are set to $0$, assuming symmetry.
