But the avionics were showing their age. Buttons on the radios and transponder were wearing out from sheer hours of use. Display streaks on the MFD made you think it had been left out in the rain. The GPS database could no longer be updated with all modern approach fixes. The autopilot ready light no longer lit. The engine monitor sort-of told you the EGTs and CHTs if you brought your reading glasses and the sun wasn't too bright.