ATSA ATC Simulation: Collision Game and Math Explained

The ATSA's ATC simulation shows numbered dots (candidates also call them balls) moving in straight lines across a simple radar-like map. Your job is to prevent collisions by typing the number of a dot to remove it, ideally removing as few dots as possible. Scenarios start with two slow dots and build up to seven or more. In a second part, short arithmetic questions with four answer choices flash up while the traffic keeps moving, so you have to divide your attention between separation and math.

The FAA doesn't publish how this section looks or how it's scored, and the items are proprietary to the test vendors. This guide relies on candidate reports from 2016 onward and on Pearson VUE's statement that the ATSA covers "decision-making ability, spatial awareness, multitasking, and working memory, among others." Treat specific keys, counts and timings as candidate-reported and subject to change.

What the section asks you to do

Part 1: collisions only

A detailed 2016 write-up on the pointSixtyFive controller forum, and later candidate posts, describe the first part like this:

• Dots numbered 1 to 9 fly in from outside the map, each on a straight path, at different speeds and headings.
• If two dots are going to collide, you remove one of them by typing its number on the numeric keypad. Removing both isn't necessary.
• If nothing needs removing, you press 0. The 2016 writer warned not to press it too soon, because once you do, you can't remove any more dots in that scenario.
• Early scenarios are simple; later ones have around seven to nine dots at once, and some collisions come within a second or two of a scenario starting.

Candidate-reported, and not entirely consistent: a 2022 candidate said they didn't see the "press 0" rule in the on-screen instructions and that dot speeds looked similar to each other, while others describe it clearly and mention varied speeds. A 2021 candidate said collided dots turned red, which was the only immediate feedback they noticed anywhere in the test. Read the instructions on the day, twice if needed.

Part 2: collisions plus math

The second part keeps the traffic and adds arithmetic questions, reportedly shown on screen alongside the traffic with four answer choices. Candidates describe:

• Addition, subtraction, multiplication and division, some with fairly large numbers.
• Questions visible for only about two to three seconds, then disappearing. The 2016 writer noted you could still answer after a question vanished, until the next one appeared.
• Answer choices reportedly listed in ascending order, lowest first.
• Answer keys that changed over time: function keys with an overlay in 2016, and A, S, D and F after Pearson VUE began administering the test, according to a 2021 candidate.

Several candidates describe the math as nearly impossible to finish exactly in the time given. One who reported a Best Qualified result in 2021 wrote that they couldn't really solve the questions and believed the test was checking their ability to decide quickly. That's one person's experience, not a scoring rule, but it's a useful reminder not to let the math swallow your attention.

How it's scored, as far as anyone knows

The FAA hasn't published the scoring for any ATSA subtest. The 2021 DOT privacy impact assessment only says the vendors' scores are combined by an FAA algorithm into a single ATSA result. The 2016 candidate write-up believed you earn more credit for removing the fewest dots necessary and for avoiding collisions. Those two aims, plus answering the math, are the sensible things to optimize:

1. No collisions. A collision is the one clearly bad outcome.
2. No unnecessary removals. Removing a dot that wasn't in conflict, or removing both dots in a pair, is inefficient.
3. Math answered. Accuracy where you can, a quick best estimate where you can't.

Our practice version scores those three things separately so you can see which one is costing you, but that's our design choice, not a copy of the real scoring.

Worked example: fewest removals

An original illustration. Four dots are on screen:

• Dot 3 is heading east along the upper part of the map.
• Dot 5 is heading east along the lower part of the map.
• Dot 8 is heading south, and its path crosses both dot 3's line and, later, dot 5's line at the moments each of them arrives there.
• Dot 1 is heading west in a corner, away from everyone.

There are two conflicts, 8 with 3 and 8 with 5, and one dot in common. Removing 8 solves both with a single keypress. Removing 3 and 5 would also prevent both collisions, but takes two removals. Dot 1 is irrelevant; leave it. Once 8 is gone and nothing else converges, you'd press 0, if that's what the instructions ask for.

Spotting conflicts faster

Scan for crossing lines, then check timing

Two dots can only collide if their paths cross. First look for paths that intersect, then ask whether both dots will reach the crossing point at about the same time. A fast dot far away and a slow dot close by can arrive together; two dots at similar speeds and similar distances from the crossing usually will.

Deal with the most urgent conflict first

Whatever is closest to colliding gets the first keypress. Resist fully analyzing the whole screen before acting when a pair is about to meet.

Look for the common dot

When one dot is involved in more than one conflict, removing it is almost always the efficient choice.

Watch for head-on and same-line traffic

Dots moving toward each other on the same line close their gap at their combined speed and are easy to underestimate. A faster dot catching a slower one on the same path is the other easily missed case.

Be ready from the first second

Candidates report collisions that happen very soon after a scenario begins. Keep your fingers on the keypad between scenarios and look for the fastest-closing pair first.

Handling the math without losing the traffic

If the options are listed lowest to highest, as candidates report, a rough estimate often gets you to the right answer faster than exact calculation. Original examples:

• 462 − 238. The last digits give 2 − 8, so borrow: the answer ends in 4. Size: a little over 200. Pick the option around 224 that ends in 4.
• 46 × 21. 46 × 20 is 920, plus 46 is 966. If you only have a second, "about 950 to 1,000" plus "ends in 6" usually eliminates three options.
• 1,944 ÷ 24. 24 × 80 is 1,920, so the answer is just over 80. With four ascending options, the one just above 80 is your pick.

A practical rhythm: glance at the math, estimate the magnitude, look back at the traffic, then answer. If a conflict is developing, handle the traffic first. Whether an unanswered math item scores worse than a wrong one isn't published; the 2016 writer said the instructions didn't say whether guessing hurt.

Common mistakes

• Removing both dots in a conflicting pair.
• Removing dots "just in case" when their paths never meet.
• Pressing 0 before the picture is settled, which (per candidate reports) locks you out of removing anything else.
• Staring at a hard multiplication while a collision happens.
• Typing the wrong number under pressure. Candidates mention fat-fingering the keypad; practice on a real numeric keypad.
• Practicing only with busy screens. A 2022 candidate found the gradual build-up from two dots different from the always-busy practice software they'd used.

How to practice

Mental math apps help with the arithmetic, and any game that makes you predict moving objects helps a little with the traffic. What they don't train is doing both at once on a keypad, which is the point of this section.

Our ATC Simulation demo uses original, generated scenarios that ramp from two dots upward, with a part that adds multiple-choice math. It's built from public descriptions, so the visuals and pace won't match the real test exactly, and no practice tool can guarantee a band. The spatial habits from Visual Relationships and the keypad speed from Number Differences both carry over. For the bigger picture, see the ATSA overview, how results are grouped in ATSA score bands, and pricing.

Frequently asked questions

Should I remove both dots that are going to collide?

No. Candidate reports agree that removing one dot of the pair prevents the collision, and the aim is to remove as few dots as possible.

What does pressing 0 do in the ATC simulation?

Candidates describe 0 as the way to indicate that no dots need removing, and warn that once you press it you can't remove any more in that scenario. At least one candidate didn't see this rule in the instructions, so check what your version says.

How hard is the math?

Candidates describe a mix of operations with some large numbers, shown for only a few seconds with four ascending answer choices. Many say they couldn't solve every question exactly and relied on estimation.

Which matters more, the traffic or the math?

The FAA hasn't published the weighting. Collisions are the clearest failure in a task modeled on air traffic control, so most candidates prioritize the traffic and estimate the math.