Duncan Aviation Avionics Instruments Technicians work on hundreds of radar units a year performing repairs and overhauls. On a weekly basis they receive units with squawks that can be attributed to corrosion.
While a radar unit is at Duncan Aviation for repair or overhaul, it is thoroughly inspected, repaired and cleaned of all corrosion. A protective coating is applied on the circuit boards to help prevent corrosion from taking hold.
Although corrosion cannot be totally prevented, there are preventative maintenance steps an operator can take in order to slow the process down.
Because radar units are located inside the radome at the nose of the aircraft, it is very important the cone has a solid seal against the fuselage to keep rain and other contaminants out of the area and away from the avionics units.
If the radome doesn’t seal properly, the aircraft’s radar will quickly become corroded. We’ve had radar units back in the Duncan Aviation Avionics Shop within a month of overhaul due to advanced corrosion inside the radome area.
The radome is made of fiberglass with a rubber seal around the edge to prevent moisture entering into this protected area. Over time, due to routine maintenance, as the radome is opened and closed the rubber seal can begin to chafe against the aircraft and become damaged. This could allow rain and moisture to enter that will cause major corrosion issues if not caught early.
If you begin to see the rubber seal looking worn or find moisture inside the radome area, we recommend you begin to use an RTV sealant around the cone as an added precaution.
TDR 94/94D Common Error Codes
Aircraft Compass System Alignment Formulae