Avionics upgrade acceptable to the CAA/JAA
A friend is currently in the process of an avionics upgrade in his TB-20 over in the States. He's going to be going for a Sandel EHSI, Engine Monitoring Display unit by a company called Advanced Control Systems and possibly an electronic ADI (if he can find one small enough). The copilot instrumentation will remain analogue. He eventually wishes to bring he's aircraft over to the UK with a view to convert it on to the G register! Where can I find information on whether or not any of the kit he is planning to Install will be acceptable to the CAA/JAA a.) Generally and b.) for IFR flying?
Thanks