FAA Sport Pilot Airplane (SPA)Airspace and NavigationMedium
A pilot plans to fly at 4,000 feet MSL, 25 nautical miles from the primary airport of a Class B airspace area, remaining clear of the Class B lateral boundaries. What equipment is required for this flight?
- ANo special equipment is required since the aircraft remains outside the Class B lateral limits
- BAn operable Mode C transponder and ADS-B Out, because the flight is within the 30 NM Mode C veil
- CA two-way radio and transponder are required only if landing at the Class B primary airport
- DA Mode C transponder is required only if the aircraft is above 10,000 feet MSL
Show answer & explanationAnswer & explanation
Correct answer: B. An operable Mode C transponder and ADS-B Out, because the flight is within the 30 NM Mode C veil
14 CFR 91.215 requires an operable Mode C transponder (and ADS-B Out per 91.225) within 30 nautical miles of a Class B primary airport, from the surface up to 10,000 feet MSL, regardless of whether the aircraft enters the Class B airspace itself.
Why the other options are wrong
- A. Being outside Class B does not exempt the flight from the surrounding Mode C veil.
- C. The requirement is based on proximity to the primary airport, not on intent to land there.
- D. The requirement applies below 10,000 feet within 30 NM, not only above it.
Mode C Veil
An imaginary 30 NM radius circle around a Class B primary airport, from the surface to 10,000 feet MSL, within which an operating Mode C transponder and ADS-B Out are required.
- 30 NM radius from Class B primary airport
- Applies even if aircraft avoids Class B airspace itself
- Extends from surface up to 10,000 feet MSL
- Charted on sectional charts as a thin blue circle
Memory trick: 30 miles out, transponder's about