Al,
I can see justification for requiring that a transponder be TSOd. A bad transponder doesn't just mess up its own plane, it could, in theory, lock up the entire transponder system in that area. Bad juju in a controlled airport situation. When it comes to transponders, how can an inspector know it "meets the requirements" of the TSO if it doesn't have the TSO certification? So, your "jerk" requires that TSO certification. However, this doesn't apply to an altimeter or any other instrument in the Ercoupe, at least not for our kind of flying. Are we agreed that for instruments other than transponders, no TSO is required? (Note that Linda has already jumped through the hoops to figure out TSO requirements for the com radios. http://edburkhead.com/Ercoupe/radio_tso_requirement.htm ) Ed
