Home' RTCA Documents for Review : DO_XYZ_SPR_SC213_WG_79_OC_FRAC Contents 15
© 2018 RTCA, Inc.
Safety and Performance Requirements (SPR)
The outcome of the Safety and Performance Requirements (SPR) assessment for the ETOS
application is presented in the following where the ETOS intended function is:
An EFVS and associated aircraft systems which allows the pilot to safely track and
maintain the runway centerline during a takeoff from brake re-lease on the runway to liftoff
and climb to 35 ft. AGL, and from brake release through deceleration to a stop for a rejected
takeoff, in natural visibilities lower than authorized without the use of EFVS.
The safety and performance requirements detailed here are the requirements that resulted
from the Operational Performance Assessment (OPA, Appendix B) and the Operational
Safety Assessment (OSA, Appendix C), based on the operational requirements created
from the Concept of Operations (ConOps) or Operational Services and Environment
The OPA derives Performance Requirements (PR) by examining all Operational
Requirements (OR) and assumptions defined in the OSED. Performance Requirements
establish the minimum requirements for the ETOS application under nominal and non-
normal conditions. The OPA is found in Appendix B.
The minimum requirements were established consistent with other systems and subsystems
used for the same intended function and phase of flight.
Operational experts also provided important feedback, in operational terms, for what
minimum performance is needed from the ETOS equipment to support their operational
needs and to provide operational benefit.
Safety Requirements (SR) were derived in the OSA by considering potential Operational
Hazards to which the flight crew and/or aircraft might be exposed during the ETOS
application, in order to control the likelihood of the Operational Hazards being encountered
and their Operational Effects experienced. The structure for an OSA is found in Appendix
C including example Functional Hazard Analysis (FHA).
Two OSAs are presented. The OSAs define takeoff minima – as a function of the
prevailing natural visibility – that are achievable through the use of vision systems
technologies, treated as subsystems, which together with other subsystems including
navigational aids and/or airport lighting and/or markings, are used to accomplish the
operational goal, achieve levels of reliability, availability, and integrity appropriate to the
The two EFVS takeoff visibility minima conditions and associated OSAs are, in summary:
1. No lower than 500 ft visibility on a Type 1/E runway or equivalent/better, with at
least 2 Runway Visual Range (RVR) reports, High Intensity Runway edge Lights
(HIRLs); and an electronic definition of the runway centerline or center by means
of an XLS (Generic Landing System, described in following).
2. No lower than 1000 ft visibility and visible Runway Centerline Markings
(RCLMs) or HIRLs/Medium Intensity Runway edge Lights (MIRLs), if RCLMs
obscured. RVR reporting is not required. An electronic means to define runway
center or centerline may be used to augment this operation and is required in the
absence of visible RCLMs or HIRLs/MIRLs.
Links Archive DO-281C Navigation Previous Page Next Page