Originally Posted by
much2much
transponder malfunctioning on mode c , reading 15000ft at 2000 . 11000 at 1100.. its not connected to a encoding alt ie is blind , any ideas??
In every instance where I have seen similar symptoms the remote encoder itself had failed. They don't seem very reliable but they are easy to function check and unless mounted in a silly place, usually easily replaced and not that expensive (By airplane standards I mean).