Depending on the headset you are purchasing, you may have the option of different plugs. Some manufacturers may offer only a fixed wing version or a helicopter version, where others have a wider selection. Your aircraft will typically only accept one type of plug, so it is important to make sure you order the correct one.
Below you will find a comprehensive dive into the various plugs and what they are used for/who uses them etc. to help you work out what you need! And if you have any questions at all or just need some help working out whats what, then please just contact us, we are here to help!
Quick Quide:
Or check below for more detailed descriptions.
- For General Aviation, fixed-wing training Pilots and most Boeing 737's (Cessna, Piper, etc.) → GA Dual Plugs (PJ-068 & PJ-055)
- For Helicopter Pilots → U174/U (Helicopter Plug)
- For Corporate Jets & Panel-Powered Aircraft → LEMO 6-Pin
- For Airbus Pilots → XLR-5 (Airbus Plug)
- For Military Aircraft → U384/U (Military Standard Plug) (Not covered below)
Also see below the detailed plug descriptions for some information about ANR vs PNR and the use of Bluetooth in aviation headsets.
1. General Aviation (GA) Dual Plugs (PJ-068 & PJ-055)
The standard for general aviation (GA) aircraft, these two separate plugs (one for the headphones and one for the microphone) are commonly used in piston-engine planes like Cessnas and Pipers.
Usage:
- Most commonly used in general aviation (GA) aircraft, such as Cessna, Piper, Beechcraft, and Diamond.
- Works with standard avionics found in piston-powered and light twin-engine aircraft.
- Easy to find adapters to convert to other plug types.
- Requires an external battery pack for ANR headsets.
Description & Technical Details:
- PJ-068 (Speaker/Audio Plug):
- 6.35 mm (1/4-inch) diameter
- TRS (Tip-Ring-Sleeve) connector for mono audio output
- PJ-055 (Microphone Plug):
- 5.25 mm (0.206-inch) diameter
- Tip-Sleeve (TS) connector for microphone input
- Power Source: No built-in power for Active Noise Reduction (ANR); requires a separate battery pack if ANR is needed.
2. U174/U (Helicopter Plug)
The U174 (or Heli, or NATO) plug is used on Helicopters. It is a single plug for both the earphones and microphone, and is a bit shorter and fatter than the GA plugs. Helicopter headsets will also typically have a coiled cord, rather than a straight cord like GA headsets.
Usage:
- Standard for both civilian and military helicopters, such as Bell, Sikorsky, and Airbus helicopters.
- Common in rotorcraft that use high-impedance systems.
- Not compatible with fixed-wing aircraft without an adapter.
Description & Technical Details:
- Connector Type: Single cylindrical plug (U174/U), also known as TP-120.
- Size: 7 mm (0.276-inch) diameter.
- Pin Configuration: Four-conductor plug (TRRS: Tip-Ring-Ring-Sleeve).
- Power Source: No built-in power; ANR headsets require an external battery pack.
3. LEMO (6-Pin)
A six-pin connector used in high-end general aviation and corporate aircraft with built-in panel power. It powers ANR headsets without batteries and offers a single-plug solution.
Usage:
- Common in high-end general aviation (GA) and corporate aircraft.
- Found in aircraft with built-in headset panel power, such as Cirrus and some Beechcraft models.
- Provides direct power for ANR headsets, removing the need for a battery pack.
Description & Technical Details:
- Connector Type: 6-pin circular LEMO connector.
- Power Source: 12-28V DC power supplied by the aircraft.
- Pin Configuration:
- Pin 1 – Microphone Input
- Pin 2 – Microphone Ground
- Pin 3 – Audio Left
- Pin 4 – Audio Right
- Pin 5 – Ground
- Pin 6 – Power
4. XLR-5 (Airbus/Panel Power)
A five-pin XLR connector found in Airbus aircraft and some business jets. Like the LEMO plug, It provides power for ANR headsets directly from the aircraft, eliminating the need for batteries.
Usage:
- Used primarily in Airbus aircraft and some business jets.
- Provides a power source for ANR headsets
Description & Technical Details:
- Connector Type: 5-pin XLR (male plug).
- Power Source: 5V DC power supplied by the aircraft.
- Pin Configuration:
- Pin 1 – Microphone Ground
- Pin 2 – Microphone Signal
- Pin 3 – Headphone Ground
- Pin 4 – Headphone Signal
- Pin 5 – Power for ANR
A quick word on ANR vs PNR headsets:
Aviation headsets come in two main types based on noise reduction technology: Active Noise Reduction (ANR) and Passive Noise Reduction (PNR). The key difference lies in how they reduce ambient noise in the cockpit.
ANR headsets use built-in microphones and electronic circuitry to actively cancel low-frequency noise. They work by detecting incoming noise and generating an opposite sound wave to neutralize it. This makes them highly effective in reducing engine and wind noise, particularly in louder aircraft like turboprops and jets. ANR headsets require a power source, either from an internal battery pack or panel-powered systems like LEMO or XLR-5 connections. Pilots who fly frequently or take long flights often prefer ANR headsets for their superior comfort and reduced fatigue.
PNR headsets, on the other hand, rely solely on soundproofing materials such as thick ear seals to block noise. They are more affordable and don’t require a power source but generally don’t provide as much noise reduction as ANR headsets. PNR headsets are a popular choice for student pilots or those flying in quieter general aviation aircraft where excessive noise isn’t a major issue.
Do I need Bluetooth?
Bluetooth functionality in aviation headsets enhances communication and connectivity by allowing pilots to wirelessly connect to external devices. While it does not replace the primary aircraft radio system, Bluetooth is commonly used for connecting to smartphones, tablets, and electronic flight bags (EFBs) like ForeFlight or Garmin Pilot. This enables pilots to receive ATIS (Automatic Terminal Information Service) updates, make phone calls on the ground, or listen to music during non-critical flight phases.
Many high-end ANR headsets, such as the Bose A30,Lightspeed Delta Zulu and the Haast HA-600A feature Bluetooth for hands-free communication and audio streaming. Some headsets also allow pilots to mix Bluetooth audio with intercom transmissions, ensuring they never miss critical radio communications. While Bluetooth adds convenience, its use in high-workload flight environments should be managed carefully to avoid distractions.
Headset Plug Adapters
Most plug types listed above can use a simple plug adapter to change your headset to another plug type. Almost all plug types have an adapter to all other plug types.
Downunder Pilot Shop stock a range of adapter cables for converting one type of headset plug to another. You can find them here.
