Certification of rotorcraft by flight simulation has been exploited in the past on a case-by-case basis to reduce the cost and flight test safety risks associated with certification. To allow the exploitation of this approach by all relevant stakeholders, it is necessary to consolidate past experience and dedicated research into a set of guidelines supported by both the industry and the certification authority. The methodology defined will include the selection of the metrics to be used for model and cueing systems fidelity. Rotorcraft models and simulation cueing systems must be evaluated in terms of agreed metrics. RoCS will develop a set of standard tools to be used to evaluate these metrics in a fast, efficient and reliable way.
Flight simulators are traditionally defined for training, with a focus on the positive transfer generated on the trainee. The development of a FS for certification purposes requires a change from this point of view, because for certification the models must be both high fidelity and physically representative of the aircraft, to ensure that the correct response of the actual aircraft will be simulated in the FS. This may also be outside of the OFE, or the envelope tested during flight tests. In this situation, pilot cueing is important as far as it is able to trigger the correct behaviour of the pilots who are testing the capabilities of the vehicle to be certified. Consequently, a new product has to be developed. It must be competitive in terms of acquisition and maintenance costs in comparison to flight tests, and affordable also by small companies, to be a driver for the development of new certified aircraft.
The introduction of a flying vehicle with a new configuration often introduces many uncertainties in the definition of the correct CS to be applied, and consequently in the choice definition of appropriate testing to demonstrate safety. The availability of guidelines for CSRFA verified on tiltrotors will represent a formidable tool to compensate for the lack of experience of both the manufacturers and the certification authorities, limiting significantly the amount of hazardous flight testing to be performed.
The industry and certification authority are engaged to define the list of certification topics that are thought to be suitable for compliance demonstration by flight simulation (WP2). A subset of these certification topics will be selected for case study in the next phase. In parallel, WP3 and WP4 will work on the identification of the starting points for the investigations, with the definition of the related simulation fidelity metrics with input from Leonardo Helicopters and the certification authority. These metrics will then be tested against the baseline simulation models and facilities available at LH, representing the current industry state-of-the-art. Additionally, in WP6 a thorough analysis of the current LH FS hardware and software, and future requirements, will be performed to develop a plan for the required initial improvement of the existing FS helicopter cabin.
The initial improvements will be implemented before the end of Phase I to enable the assessment of the agreed fidelity metrics of the LH FS with the upgraded hardware.
Phase II starts with the definition of the related simulation fidelity metrics with input from LH and the certification authority. After the identification of the capability gaps, improvements to the flight simulation models and simulator cueing environment will be investigated using models provided by LH and consortium simulation facilities.
Concerning modelling, current helicopter and tiltrotor models will be developed and tested for the specific CSRFA topics (Certification by Simulation for Rotorcraft Flight Aspects) identified for demonstration within the project. In light of the time constraints of the project, the LH simulator upgrade will be performed in parallel with the other activities. The findings of Phase II will be incorporated in a preliminary set of guidelines for interim evaluation by the certification authority. WP6, in close connection with WP4, will develop a design for the new FS hardware, which fulfils requirements (as much as possible) determined in WP4.
Phase III will see the consolidation of the final set of guidelines, their application to the LH AWARE simulation facility, and the demonstration through application to models of the Next Generation Civil Tilt Rotor Technology Demonstrator (NGCTR-TD) and the NGCTR New Tilt Rotor Concept (NGCTR-NTC). Piloted simulations will be performed, initially on the helicopter selected by LH. These will be followed by verification of the applicability of the proposed approaches to the NGCTR tiltrotor models.