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What does ATC stand for in climbing?

ATC stands for air traffic controller! If you just started climbing, chances are that you’ve seen, heard about, or used a Black Diamond tube-style belay device, but it’s been referred to as an ATC.

How often have you heard someone say, “belay me with your air traffic controller”? I never have, but I have often wondered what does ATC stand for?

The reason for this name came about because when a climber fell, their belayer literally controlled the person hanging in the air.

The Black Diamond Air Traffic Controller (ATC) is an awesome device because it can be used for belaying and rappeling.

With the two openings, we can use the device for a double rope rappel. The friction provides an easy user experience for top rope and lead belaying. The downside is that there isn’t any assisted braking functionality.

What is a tube style belay device?

Tube style belay devices are one of the most common styles for belay devices in rock climbing today. We use these ATC devices because they make belaying easier by creating friction.

An ATC needs to be clipped into the harness with a locking carabiner, the rope then runs through the bottom of the device, around the carabiner, and then back out through the top of the device.

An ATC won’t have all of the bells and whistles like an assisted braking device, but it’s extremely worthwhile for a beginner to use an ATC.

Learning proper belay technique is crucial when learning how to climb and how to belay. What if we are using an assisted braking device that happens to fail? We need a backup. And that backup is proper belay technique.

Black Diamond belay devices with a Petzl Reverso that snuck in!

Types of ATC Devices

Right now, Black Diamond makes a few different types of the ATC. Each one serves a different purpose. If you are just starting out with climbing, but think that you might eventually climb outdoors.

I highly recommend purchasing the ATC Guide. This belay device comes with the ability to be used in “plaquette mode”. This is just a fancy way to say that we can belay a climber off an anchor with an auto blocker in place.

Black Diamond ATC Belay Device


  • The most affordable option
  • Lightweight at only 60 grams
  • Simple to use


  • Can’t be used for belaying from above. Not useful for multipitch climbing
  • Does not have extra teeth for high friction mode

The Black Diamond ATC Belay Device is the original ATC. It is the original model and has beauty in its simplicity. It can handle ropes from a diameter of 7.7mm to 11mm.

The best part is that this device only weighs 60 grams, practically nothing and you’ll be able to belay and rappel with it.

Black Diamond ATC XP Belay Device


  • Extra teeth for high friction mode for belaying and rappelling
  • Lightweight, only 64 grams


  • Does not have a plaquette loop for belaying from above

The Black Diamond ATC XP is similar to the original ATC. It provides rappeling and belaying functionality, but it comes with a teeth side that lets you use the device in “high friction mode”. This high friction mode offers a 3X increase in holding and stopping power.

Personally, this is my favorite device to give to beginners. It teaches them proper belay technique.

The device still handles ropes of 7.7mm to 11mm diameter. And only weighs 64 grams! The extra friction is well worth the four grams of added weight.

Black Diamond ATC Guide


  • Extra teeth for high friction mode
  • Plaqauette loop to belay climbers from above


  • More expensive at $32
  • An extra 20 grams, heavier than the XP

The ATC Guide is hands down one of the best devices on the market. This ATC stands to be one of the most commonly used devices for outdoor climbing. It can be used for belaying, rappeling, and belaying from the top of a pitch. Belaying from the above is a crucial skill for a multi pitch climb since you’ll be climbing high off the deck. .

The device does weigh more than the previous two devices, coming in at 84 grams. It also can only handle a rope as thin as 8.1mm. But the pros far outweigh the cons for this device.

Black Diamond ATC – Alpine Guide


  • Lighter than the ATC Guide at 73 grams
  • Optimized for alpine climbing


  • Can only be used for alpine climbing, niche use case
  • Does not support larger rope diameters

This ATC device is the same as the ATC Guide, but has been optimized for alpine climbing. The ATC Guide is lighter and can handle skinnier ropes that are generally used during alpine missions. Other than that it’s the same solid device.

This device weighs 73 grams, but only supports ropes that are between 6.9mm and 9mm. However, any rope between 6.9mm and 9mm will work. Due to the diameter width restriction, this isn’t a good choice for beginner climbers. But it’s a great option for alpine climbing.

What other types of belay devices are there?

The air traffic controller is a subset of tube style belay devices. Nearly every climbing manufacturer has their own version of an air traffic controller but will be called something else. Petzl offers both the verso and reverso, which are similar to the Air Traffic Controller and Air Traffic Controller Guide.

Assisted Braking Devices

Assisted braking devices, like the Petzl GriGri, are becoming incredibly popular. Some gyms even ban the use of tube style devices. These gyms will have grigris permanently fixed to the rope.

Ultimately, I think this harms people in the long run. Climbers will miss out on perfecting their belay technique which could have serious consequences if the ABD were to fail.

Photo of author
Rob developed ORB to help himself categorize and find all the outdoor gear he needed at great prices. He loves writing about the outdoors and climbing. Rob is a certified Single Pitch Instructor through the AMGA.

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