What are the three types of transponders?
It automatically receives radio signals from interrogators on the ground, and selectively replies with a specific reply pulse or pulse group only to those interrogators being received in the mode in which the transponder is set. There are three main types of transponders: A, C, and S. Mode A. When the transponder receives an interrogation request, it broadcasts the configured transponder code (or squawk code). This is referred to as Mode 3A or more commonly, Mode A. A separate type of response called Ident can be initiated from the airplane by pressing a button on the transponder control panel .
What are the different transponders?
Types of Aircraft Transponders There are three primary categories of aircraft transponders: Mode A, Mode C, and Mode S. Each adds additional information and capability. Two‐way radio communications and operational transponder are normally required for operations within Class C airspace, but operations without radio communications or transponder can be conducted by LOA, facility directive, or special arrangement with Class C airspace controlling facility.Class C service requires pilots to establish two‐way radio communications before entering Class C airspace. If the controller responds to a radio call with, “(a/c call sign) standby,” radio communications have been established and the pilot can enter Class C airspace.Class A, B, and C airspace: All aircraft must be equipped with an operable Mode C transponder. Class D airspace: No transponder is required unless otherwise specified by ATC (Pilots only require two-way radio communication in this class of airspace).