M. J. Powell wrote:
Is TACAN still in use? I worked on it briefly in 1956 when I was in the
RAF.


I remember from a recent history or discovery channel program that
air-to-air tacan is still used for aerial refueling operations.

Here's a page about it from Rockwell:
http://www.rockwellcollins.com/ecat/gs/TCN-550_Tacan.html

- Ray