Yes, HyperCard was pretty hot at the time. The most impressive thing I know that was made in HyperCard was the original version of the Myst computer game. Avionics pretty much refers to the electronics on an airplane. Most of what I did on that project was work on the system call interface for the little real-time operating system that supported the navigation, communications, and weapon control software. 

https://en.wikipedia.org/wiki/Myst