BEFORE YOU BEGIN
Transponder repairs on any part of the system including wiring are considered maintenance and must be conducted by authorized persons. It is your right and obligation to select who performs maintenance and how it is conducted. You have choices and this section will provide assistance and help you guard against future problems.
Through a series of simple questions and a brief function test you will quickly determine what is wrong, what kind of maintenance should be performed, and who you could use. You will not need to remove your transponder or fly into ATC airspace.
Regardless of what you decide please get your A&P involved to pull the transponder and inspect the installation. More on this will follow, but for now consider the limitations of internet based help compared to the “hands on” evaluation from a live aircraft technician.
Equally important. Never fly into controlled airspace with a known mal-functioning transponder.Select the FUNCTIONAL TESTING link to begin.
FUNCTIONAL TESTING This section was written using clear terms and should give any pilot the direction required to make a sound maintenance decision. This is the best place to begin your troubleshooting.
AIRFRAME ISSUES Should FUNCTIONAL TESTING reveal a possible airframe related issue, such as power loss or antenna problems, this section was written to provide a licensed mechanic or technician some guidance towards a resolution.
FLIGHT TESTING This discussion involves what to do after the repair such as testing and return to service.
WHO CAN PROVIDE MAINTENANCE ON A TRANSPONDER AND SYSTEM
A transponder system may be defined as the parts that are permanently installed such as the rack or tray, wiring and connectors, circuit protection, antenna and the coax (transmission line) that supplies the antenna. Interfacing items usually include an encoder (altitude reporter) and possibly a connection to a GPS, display, control head or other item.
PRIVATE PILOT: May conduct functional testing in accordance with the manufacturer's operational instructions. A private pilot may not provide maintenance on any part of the system (even preventative).
LICENSED MECHANIC: May remove the transponder to test and inspect wiring, security and interfacing.
CERTIFIED REPAIR STATION: May provide both of the above plus recertification and repairs if appropriately rated. Many CRS holders perform testing only.
MANUFACTURER OF TRANSPONDER: May provide repairs but not authorized to recertify.
THIS AGENCY: All of the above. However unless you can bring the aircraft to us you will need a licensed mechanic to perform maintenance on the system.