What suffix is used for an aircraft with No DME and a transponder?

The suffix used for an aircraft with No DME and a transponder is indeed represented by the specific letter assigned in aviation communication protocols. In this context, the suffix indicates the capabilities of an aircraft.

For an aircraft that does not have DME (Distance Measuring Equipment) but is equipped with a transponder, the suffix /X is utilized. This is part of a system that helps air traffic control and other aircraft understand the equipment and capabilities of the flying vehicle. The /X designation implies that while the aircraft can be tracked via radar because of the transponder, it does not possess DME functionality, which is used to determine distance from a ground-based station.

Thus, by employing this suffix, controllers can make informed decisions about navigation, separation, and communication with the aircraft based on its capabilities. The other suffixes represent different combinations of available equipment and are not applicable in this situation.