MOC 3 VTOL.2300 Validation of Electronic Flight Control Laws (FCL) in Fly-by-Wire flight control systems

• n/a found in: Small Category VCA (Revision 0) SC-VTOL (Oct 2024)

MOC 3 VTOL.2300 Validation of Electronic Flight Control Laws (FCL) in Fly-by-Wire flight control systems n/a Compliance of the electronic flight control laws should be considered satisfactory when an adequate substantiation of validation activities is shown and formalised in the compliance documents. (a) Formalisation of compliance demonstration strategy In order to demonstrate compliance with an adequate level of formalisation, the following should be performed and captured within compliance documents: (1) Determination of flight control characteristics that require a detailed and specific validation strategy for [VTOL.2135](#_DxCrossRefBm1877490390), [VTOL.2145](#_DxCrossRefBm1877490414), [VTOL.2300](#_DxCrossRefBm1877490411), [VTOL.2500](#_DxCrossRefBm1877490409), [VTOL.2510](#_DxCrossRefBm1877490363) compliance and Modified Handling Qualities Rating Method (MHQRM) demonstration; (2) Substantiation of the proposed validation strategy (e.g. analyses, simulator tests, flight tests) covering the characteristics and features determined above. (b) Validation activities For the substantiation of the proposed validation strategy, the applicant should perform the following activities: (1) Identify the objectives (intended function) of each function. (2) Check proper integration of each FCL function in the EFCS (Electronic Flight Control System) against objectives (e.g. rig-test, offline/piloted simulation, flight test, …). (3) Check compatibility of each function with other functions acting on the same control surface/actuator: (i) Identify potential interface problems with other functions, (ii) Define test conditions (e.g. rig-test, offline/piloted simulation, flight test, …), (iii) Particular consideration should be given to actuator limitations and the resulting coupling of the remaining control authority between different control functions. (4) Check compatibility of each function in all applicable modes with other functions at aircraft level: (i) Identify potential interface problems with other functions on aircraft level, (ii) Define test conditions (e.g. rig-test, offline/piloted simulation, flight test, …). (5) Analyse failure conditions for each function: (i) Identify failure conditions and classify the severity of failures in accordance with [VTOL.2510](#_DxCrossRefBm1877490363), (ii) Define test conditions for verification of failure conditions severities (e.g. rig-test, offline/piloted simulation, flight test, …). (iii) Where functions are acting on the same control surface/actuators, particular consideration shall be given to coupling of failures in these functions (including control margin dependencies) as well as the overall redundancy management between these functions (including actuator limitations). (6) Document all steps. (c) Characteristics For the validation activities identified by the paragraphs (b) 2 to 5 above, the following should be covered in particular: (1) Definition of priorities between FCL functions acting on the same control surface / actuator (e.g. priorities, mixing-laws, …), (2) Multi-objective optimisation (e.g. trajectory, energy consumption, passenger comfort), including trading one criterion (e.g. airspeed) vs others in extreme conditions, (3) Transition between different FCL modes with and without failures (e.g. blending, fading-in/fading-out, smoothness of transition, …), (4) Effects of erroneous input data (e.g. air data, aircraft configuration, …), (5) Discontinuities and non-linearities, (6) Control law interfaces, (7) Voting mechanisms, (8) Protections priorities (e.g. entry/exit logic conditions not symmetrical), (9) Determination of critical scenario for multiple failures. The validation strategy should include but should not be limited to operational scenarios. The determination that an adequate level of validation of the FCL design has been achieved should be based on engineering judgment. (d) Documentation to be provided The applicant should prepare a checklist with a defined set of test cases based on experience, and provide the FCL Validation methodology and strategy for verification by the Agency. (e) Auditing The Applicant should perform adequate auditing and the Agency may define a related Level of Involvement in such audits. Compliance should be shown in conjunction with the following requirements: [VTOL.2135](#_DxCrossRefBm1877490390), [VTOL.2145](#_DxCrossRefBm1877490414), [VTOL.2500](#_DxCrossRefBm1877490409) and [VTOL.2510](#_DxCrossRefBm1877490363).