600840-000031 Stratus ES/ESG Installation Instructions
Rev. 2.2
Last Revised: February 20, 2018
Page 12 of 45
1.4.
Non-TSO functions
Below are Stratus ES/ESG’s non-TSO functions:
•
VFR key (and configuration).
This non-TSO function does not interfere with Stratus ES/ESG’s compliance with the
requirements of the TSOs listed in Section 1.2.
1.5.
Environmental qualifications
Stratus ES/ESG is tested to DO-160G. The Stratus ES/ESG Environmental Qualification form is
found in Appendix A of this document.
1.6.
Criticality level
Software level determination is based on the Functional Hazard Assessment (FHA) and
Preliminary System Safety Assessment (PSSA). These assessments determined that the most
severe failure conditions (see Table 3) are classified as Major. As such, the Software Assurance
Level has been determined to be Major.
Major failure conditions would reduce the capability of the aircraft or the ability of the crew to
cope with adverse operating conditions to the extent that it would be a significant reduction in
safety margins or functional capabilities or a significant increase in crew workload. Software
whose anomalous behavior would cause or contribute to a failure of the system function
resulting in a Major failure condition for the aircraft is identified as Level C.
Function
Description
Classification
ATCRBS / Mode S
Transponder
Malfunction of the ATCRBS / Mode S
transponder function without warning
Major
ADS-B Out
Broadcast of incorrect ADS-B messages
without warning
Major
GPS/SBAS Receiver
(Stratus ESG only)
Loss or malfunction of the GPS/SBAS receiver
function
Major
Pressure Altitude Output Failure of the pressure altitude output function
Major
RF Feed-Through
Malfunction of the RF feed-through function
without warning
Major
Table 3: Criticality level
