Formalization of flight mechanical CS-25 requirements for assessments using flight simulation in preliminary aircraft design

For the development of new aircraft, manufacturers already employ numerical computation methods with increasing modelling accuracy in the early design phases, benefiting from the increasing computational power available today. These methods are utilized by the system design departments to create high-fidelity flight simulation models integrated with flight control systems. These models are then used to simulate flight tasks, assessing the impact of design decisions on the aircraft's flight mechanics, and ensuring compliance with the certification specifications. Conducting thorough and accurate assessments of these requirements using sophisticated models can significantly enhance the efficiency of the design process while reducing development costs and risks. However, directly using the certification specifications for flight simulations is not feasible. First, the requirements and their corresponding criteria need to be derived and formalized, then transformed into mathematical equations and ultimately implemented into software algorithms. Although there are existing processes to formalize and assess some requirements through simulations, these often focus on simplified and task-specific flight simulation models. As a result, adapting the models to the increasing knowledge about the aircraft and the growing level of detail in the requirements during the development process typically involves a significant amount of effort. This is where this thesis comes in. The objective is the development of a process for deriving and validating flight mechanical requirements derived from certification specifications using automated and flight simulations with a model-independent interface. The validation, implemented using software classes, of flight mechanical models at different levels of maturity, which meet certain minimum requirements, is carried out through the interface. This approach allows the utilization of high-accuracy models for more precise evaluations. The implementation of software classes enables efficient automation and scalability of the validation process, while also facilitating the reuse of these classes for different models, resulting in time and resource savings. The process is demonstrated by examples from the development of large transport aircraft to show compliance with requirements that are specified in CS-25. The work begins with an introduction to flight simulation and an overview of relevant regulations. Subsequently, a method is shown to derive and formalize flight mechanical requirements from these regulations. The class-based software architecture, developed to implement these formalized requirements, is then explained, including the necessary interfaces to the flight simulation models. The subsequent sections of the work describe the implementation and integration of these classes in the software tool MITRA (Multiobjective Evaluation of Preliminary Aircraft Designs), developed for the flight mechanical evaluation of preliminary aircraft designs. To illustrate the process, examples of formalized requirements and their verification with MITRA are shown.

Author dc:creator

• Krishnamurthy, Vikram Yadav

Advisor dc:contributor.advisor

• Luckner, Robert

Licence dc:rights.uri

• https://creativecommons.org/licenses/by/4.0/

Language dc:language.iso

en

Identifier URI

https://doi.org/10.14279/depositonce-18439

OAI identifier oai:identifier

oai:depositonce.tu-berlin.de:11303/19640