Unfortunately, corrosion under antennas is usually not found until an equipment failure is noticed. By that time, it might be too late. Most antennas are mounted to the airframe with a minimal amount of protection because bonding is critical.
Duncan Aviation recommends taking a proactive approach during a structural “C” inspection or pre-buy evaluation to remove the fuselage pressure vessel antennas and inspect for corrosion. This is especially important if the aircraft has lived its life in a corrosive saltwater environment or is showing less than optimal outside paint protection.
This is one of those decisions that is hard to justify, due to cost and access involved. However, it is often very cost effective in the long run and can provide peace of mind.
The FAA Updates 5G Guidance In Safety Alerts For Operators
Do I Need An Avionics Service Plan During Heavy Maintenance?
Don’t Go To The Las Vegas Formula One Races (Or Anywhere) Without An AOG Plan
Why Are Accurate Equipment Lists Critical To Avionics Warranty Programs?
Proper ART-2000/2100 Radar Shutdown Procedures to Prevent Unwanted Squawks