EUROCAE ED-249 PDF

Purpose

This MASPS provides high level system requirements for an Aircraft State Awareness SVS (ASA SVS). This document expands the previously defined DO-315A intended function of an SVS beyond that of supplemental view of the external scene to include enhanced aircraft attitude and energy state awareness. This document defines a system that is intended to be presented full-time on the pilots’ full color Primary Flight Displays (PFD).

Features of an ASA SVS may also be implemented on a Head-Up Display (HUD) or equivalent and standards for this are defined herein. If a HUD replaces the requirement for an HD PFD, this document may not contain all the appropriate requirements to perform the intended function and an additional assessment will need to be performed for compliance. Wherever the term HUD is used in this document, it is meant to be inclusive of a HUD equivalent type device such as a head worn display (HWD).

ASA SVS is intended to prevent the occurrence of spatial disorientation by supporting the pilots’ continuous awareness of attitude, altitude, topography and energy state (speed, acceleration and altitude) related to the flight path and perceived motion of the aircraft. In addition to reducing the risk of controlled flight into terrain (CFIT) it is intended that an SVS meeting this MASPS will reduce the risk of loss-of-control inflight (LOC-I) accidents by preventing the attainment of any unusual (i.e., not normal) attitude and/or energy states that could result in a LOC-I.

NOTE: The Commercial Aviation Safety Team (CAST) chartered the ASA Joint Safety Analysis Team in 2010 to investigate LOC-I accidents and incidents in which the flightcrew lost awareness of the airplane’s attitude and/or energy state. 274 intervention strategies (IS) were identified as mitigations to the standard problems observed in the LOC-I accident analysis. The CAST ASA Joint Safety Intervention Team reviewed the IS and developed 11 new safety enhancements (SE) including training, operations and design implementations. This MASPS was created in support of the desire to provide an industry standard for SE-200: Virtual day visual meteorological condition (VMC) displays (such as synthetic vision or an equivalent system) with energy state symbology cues. While SE-200 was identified as the highest rated design intervention in terms of risk reduction percentage. it is recognized that there exist many other impactful design interventions for reducing LOC-I that are not covered in this MASPS, e.g., Bank Alerting with Recovery Guidance (SE-201), Bank Angle Protection (SE-202), and Low Speed Alerting (SE-192).