Looking for Phd research topic - real time/embedded systems/communication buses etc.

I am in the middle of my Phd studies. My master thesis was related to
embedded systems and remote monitoring of traffic. Since I have been
always passionately interested in aviation, aircrafts etc. I would
like to mix business (I work in the travel industry) with pleasure
now. I am looking for an interesting topic connected with:
- real time/embedded systems in aviation
- communication buses, measurement systems in aircrafts
- certification of hard real time systems in aviation

I do not count on any sort of scholarship etc. just looking for
something interesting I could focus on during next 2-3 years.

Thanks in advance for your suggestions,
sebastian