AWO.A.EFVS.107 CS AWO.A.EFVS.107 Enhanced flight vision system (EFVS) safety assessment

The safety assessment should show that the applicant's specific installation meets all the integrity criteria for the aircraft systems and for the EFVS. All aircraft configurations to be certified should be addressed.

The applicant may need to assess by flight test or simulation the effects of combinations of EFVS malfunctions that are not classified as Catastrophic by the functional hazard analysis (FHA) (to support compliance demonstration to CS 23.2500(a), CS 23.2500(b), CS 23.2510, CS 23.2605 or CS 25.1309, as applicable).

The overall level of safety of the aircraft is based on installed equipment. A complete system safety assessment (SSA) should be conducted. The SSA should consider the potential for hazardously misleading information (HMI) being presented to the flight crew. Examples of HMI that should be considered include at least information providing attitude, altitude, and distance cues as outside terrain imagery, frozen and offset imagery.

EFVS fail-safe features

The normal operation of the EFVS may not adversely affect, or be adversely affected by, other normally operating aircraft systems. Detected malfunctions of the EFVS which could cause display of misleading information should be annunciated and the misleading information removed. The criticality of the EFVS's fun ction to display imagery, including the potential to display HMI, should be assessed according to CS 25.1309 and AMC 25-11. Likewise, the hazard effects of any malfunction of the EFVS that could adversely affect interfaced equipment or associated systems should be determined and assessed according to CS 25.1309 and AMC 25-11. Similar criteria can be found in CS 23.2510. This requirement should be met through an SSA and documented via fault tree analysis (FTA), failure mode and effects analysis (FMEA), and failure mode and effects analysis substantiation (FMEA substantiation), or equivalent safety documentation.

[Issue: CS-AWO/2]