The use of DDS has gained widespread adoption in command-and-control applications due to its support of the publish-subscribe communications model typically found in such systems. DDS has been field-proven in extremely complex systems consisting of thousands of endpoints with high data rates and stringent latency budgets. Nevertheless, DDS has yet to gain traction in avionics applications due primarily to their certification requirements. However, the same data-centric publish-subscribe communication and performance drivers that make DDS so attractive in the bit tactical systems also exist in avionics systems. This presentation will discuss research and prototype work towards the definition of a "safety critical" profile of DDS. We will describe an analysis of the DDS minimum profile features and relative code complexity oriented towards identifying which features could be implementable within the size constraints imposed by a "safety-certifiable" version of DDS. We identify a candidate subset of the minimum profile that has been found to meet the requirements of many avionics applications, and the lessons learned from implementing a "small footprint" version of DDS. Issues regarding the interoperability between a safety-critical implementation of DDS and a full-featured DDS implementation will be presented, along with the Quality of Service necessary and proposed for a small-footprint DDS for safety critical applications.