Sometimes selecting the correct Aviation Headset is difficult, especially when you are new to the Aviation industry. Selecting the correct headset really depends on what type of aircraft you are flying and what is installed in that aircraft. For example: we know of light departments that have had panel powered plugs installed in their cockpits. The good news however, is that there are many aviation headset adapters available for sale that will help you convert your existing aviation for just about any aircraft application.
General Aviation (Fits most Fixed Wing Airplane Applications)
Dual Male Plugs - Fixed Wing
For most of the aviation community flying fixed wing aircraft, the general aviation headset plugs are the route to go. This type of plug consists of a PJ-055 or M642/4-1 (.25 inch / 6.35mm) and a PJ-068 or M642/5-1 (.206 inch / 5.25mm) plugs. The PJ-055 provides audio to the ear cups while the PJ-068 transmits data for your microphone. This type of plugs works in most all civilian and commercial airplanes, even when other options might also work. This type of plug is the safest bet if you are unsure which plug is required for your application.
Panel Powered / Lemo Plug
Some newer aircraft such as Cirrus or a Beechcraft, have a 6-pin circular type jack in your panel. This panel power plug is called a LEMO or Redel connector and is sometimes referred to as a "Bose Style connector". This aviation plug allows the pilot bypass the requirement of batteries in their ANR (Active Noise Reduction) headset. Depending on the aircraft, installation kits are available from many different avionic and completion shops.
U-174/U or U-93A/U Plug
Most helicopters are equipped with a system that requires a short single plug. It's slightly shorter and wider than the traditional general aviation headset plugs. This single plug known as a U-174/U or a U93A/U (7.1 mm / 0.281 inch diameter) provides data from both the microphone as well as to the ear cups.
Airline & Corporate Aviation
XLR-5 Plug (AirBus) & XLR-3 Plug
Although most airline and corporate aircraft utilize the standard dual male plugs, or Lemo Plugs(Panel Powered.) Like the Lemo Plug the XLR Plugs can provide power to the headset to bypass the requirement of batteries to utilize ANR.
Military aircraft of all types generally utilize a single U-93A plug. plug which is the same size found in a civilian helicopter (U-174/U). Although they utilize the same style and size plug as the U-174/U plug found in civilian aircraft, military aviation headsets are normally low impedance instead of high impedance. Therefore, although they look similar, civilian and military headsets are not interchangeable without the appropriate adapter.
Aviation Headsets normally come in two different cord types. The most common cord is the straight cord. Coiled cords are available with some headset models and are most often found in helicopters vs fixed wing aircraft.