Transponders

[Ljbarry]

I don't think clippers came from the the factory with transponders but they do have an electrical system correct? When did the CAA or FAA require the installation of transponders and was it retroactive to older planes like clippers? Aircraft without an engine driven electrical system are exempt but clippers have one?

[Jim Hann]

The answer is the FAA does not require a transponder in ANY aircraft. It requires it to operate in certain AIRSPACE. The exemption to the transponder requirements for aircraft without an engine driven electrical system is primarily for the "Mode C veil" which in 2020 will become the "ADS-B veil" within 30 nm of a Class B airport but outside the B airspace. You still need to get "special" permission as outlined in the regs for operating inside the Class B without a transponder. It does also limit those aircraft to below either 10,000' MSL or 2,500' AGL depending on the elevation of the ground you are flying over.