By DAVE HUGHES, FAA
Some general aviation aircraft owners may not recognize the consequences of waiting to install Automatic Dependent Surveillance-Broadcast (ADS-B) Out until they discover in 2020 that they cannot easily fly out of their home airport.
Many GA airports are located in or near airspace that requires ADS-B equipage. Without ADS-B Out onboard, pilots will need to seek exceptions from air traffic controllers to depart from their home airport, which might not be granted or could lead to delays.
In 2010, the FAA published a rule mandating the use of ADS-B Out by Jan. 1, 2020, in most airspace where a transponder is required today.
Pilots who fly from GA airports in or near congested airspace may not have studied how Class B and C airspace or a Mode C veil might affect their operations to and from their home airport. ADS-B Out is required in all three of these types of airspace under the FAA rule.
You should confirm whether the following types of ADS-B airspace could affect your operations:
- Class B airspace: Airspace from the surface to 10,000 feet above mean sea level surrounding the busiest 37 airports in terms of Instrument Flight Rules (IFR) operations. Airspace configuration is individually tailored and consists of a surface area and two or more layers. Class B is designed to contain all published instrument procedures once an aircraft enters the airspace.
- Mode C Veil: This airspace within a 30-nm radius of a Class B airport from the surface to 10,000 feet requires aircraft to have a Mode C transponder with altitude reporting.
- Class C airspace: Class C airspace usually consists of a 5-nm radius core surface area from the surface up to 4,000 feet above the airport elevation, and a 10-nm radius shelf area that extends no lower than 1,200 feet up to 4,000 feet above airport elevation. These airports have an operational control tower, are serviced by a radar approach control, and have a certain number of IFR operations. There are more than 120 Class C airports in the United States.
Class B and C airspace is shaped like an inverted wedding cake. Even if a general aviation airport is not covered by the bottom layer, an aircraft may pass through Class B or C airspace on the way to or from a runway. The Mode C Veil around 37 Class B airports with a 30-nm radius extends from the surface to 10,000 feet.
GA hotspots often correlate to congested airspace where ADS-B is mandated in New York, Florida, California, and Texas.
“This is where the highest density of general aviation aircraft is located and where there are a lot of Class B and C airports,” said Jens Hennig, vice president of operations for the General Aviation Manufacturers Association (GAMA).
Nationwide, more than 20,000 general aviation aircraft are based at airports under a Mode C Veil, and those owners need to recognize how little time they have left to install ADS-B before the FAA rule takes effect.
“There are many general aviation pilots who do not fully understand where rule airspace is located,” Duke said. “Pilots should investigate how rule airspace affects them and take action soon.”