What is squawk code mode C?
What is squawk code mode C? Altitude SQUAWK or Mode C At one point, SQUAWK codes simply showed air traffic control where aircraft were on radar screens. However, SQUAWK codes were not able to detail how high or low an aircraft was flying. So, Altitude SQUAWK — or Mode C — was also invented.
Can I fly without a transponder?
A transponder is not required unless an aircraft is operating: In Class A, Class B, or Class C airspace. Above 10,000 feet Mean Sea Level (MSL), excluding airspace below 2,500 feet Above Ground Level (AGL).
Where is mode C required?
However, if you wish to operate in class A, B, or C airspace, or at an altitude of over 10,000' MSL, or within a 30 nautical mile radius of the primary airport in class B airspace, you will need a transponder and altitude encoder (commonly referred to as mode C).