Pilots are weird about tech. We fly planes worth millions with glass cockpits that look like something out of a sci-fi movie, yet many of us still carry a little plastic calculator in our flight bags. Or worse, a cardboard sliding wheel called an E6B that dates back to World War II. But if you walk into any flight school today, you’ll see the CX 3 flight computer everywhere. It’s basically the gold standard for the FAA written exam, and honestly, it’s one of the few pieces of aviation gear that actually lives up to the hype.
It’s fast.
The ASA CX-3 isn't just a calculator; it’s a dedicated machine built for a very specific purpose: making sure you don't run out of fuel or get lost in the clouds. While your iPad is great, it can die. It can overheat on a hot dashboard in a Cessna 172. It can get "lost" in a software update right when you need to calculate your crosswind component. The CX-3 just works. It’s got that rugged, "I don't care if you drop me" feel that flight instructors love.
What the CX 3 flight computer actually does for you
Most people think a flight computer is just for multiplying numbers. Nope. The CX 3 flight computer handles everything from basic arithmetic to complex wind vector analysis. Imagine you’re planning a cross-country flight from Chicago to Nashville. You’ve got a headwind of 15 knots at 240 degrees, and your true airspeed is 110 knots. Doing that math by hand with a pencil and a rotating wind face is a recipe for a headache. With the CX-3, you just punch in the numbers, and it spits out your groundspeed and wind correction angle in seconds.
It’s got functions for things you didn't even know you needed until you're halfway through a private pilot ground school course. We’re talking pressure altitude, density altitude (which is a literal lifesaver in high-altitude airports like Denver), and weight and balance. If your plane is too tail-heavy, you’re going to have a bad day. The CX-3 makes it easy to see if you need to move that heavy flight bag from the aft baggage compartment to the floorboard.
The interface is kinda retro. It’s got a color screen, but it’s not a touchscreen. This is actually a good thing. When you’re bouncing around in light turbulence, trying to tap a specific pixel on an iPhone is impossible. Tactile buttons are your best friend when the air gets messy. You can feel the click. You know the input went through.
Passing the FAA Written Exam
This is the big one. This is the real reason people buy the CX 3 flight computer. The FAA is incredibly strict about what you can bring into the testing center. You can't bring your phone. You can't bring a programmable calculator that might have cheat sheets hidden in the memory. But the CX-3 is FAA-approved.
Because it’s specifically mentioned in FAA Order 8080.6, the proctors at the testing center won't give you a hard time. It doesn't have a QWERTY keyboard, which is one of the weird rules the FAA has. If it has a full keyboard, it's a "computer" and it's banned. Since the CX-3 uses a standard keypad, it passes the test.
Honestly, trying to do the E6B "Whiz Wheel" during a timed exam is stressful. You’re trying to line up tiny little black lines while your hands are sweating. The CX-3 removes that mechanical error. If you type in the right numbers, you get the right answer. Period. It takes the "did I slide the rule correctly?" anxiety right out of the equation.
Why it beats the old school E6B
Look, there’s a certain "cool factor" to using the old manual E6B. It makes you feel like Chuck Yeager. But in reality, it’s slower and less accurate. The CX 3 flight computer can solve for a variable in a "Cloud Base" problem or a "Top of Descent" calculation faster than you can find your pencil.
📖 Related: OpenAI ChatGPT Gender Identity: Why the Bot Doesn't Have One (and Why We Keep Giving It One)
Think about it this way: the manual wheel requires you to keep track of decimal places in your head. Is it 15 gallons or 150? The CX-3 keeps the units straight for you. It handles conversions between Celsius and Fahrenheit, liters and gallons, and nautical miles to statute miles. If you’ve ever tried to calculate fuel burn for a four-hour flight and accidentally used the wrong unit, you know how terrifying that mistake can be.
- Weight and Balance: You can save profiles for different aircraft.
- Memory: It remembers your last calculation even if it shuts off.
- Backlight: Essential for night flying when you can't see your lap.
- Endurance: It runs on four AAA batteries for a crazy long time.
Wait, let's talk about the batteries for a second. Some people complain that it doesn't have a built-in lithium-ion rechargeable battery. I disagree. If you're at the airport and your flight computer is dead, you can find AAAs in the vending machine or at the front desk. If a proprietary lithium battery dies, your flight is cancelled.
The learning curve is real
Don't buy this the night before your checkride. It’s intuitive, but it’s not "iPhone intuitive." You have to understand the menus. It uses a hierarchical structure. You go into the "FLT" (Flight) menu for things like wind and groundspeed, or the "SYS" (System) menu to change the brightness.
I’ve seen students get frustrated because they couldn't find the "Leg Time" function. It’s there, but you have to know where to look. Spend a few hours with the manual—yes, the actual manual—and practice the sample problems. Once it clicks, it’s like an extension of your brain.
Is it worth the price?
Usually, the CX 3 flight computer retails for somewhere around $100 to $120. That sounds like a lot for a calculator. You could buy a fancy dinner or a couple of hours of fuel for that. But consider this: you will use this device from your very first flight lesson all the way through your Commercial Pilot certificate and maybe even your ATP (Airline Transport Pilot) rating.
It’s an investment in accuracy. In aviation, "close enough" isn't really a thing. If you're off by 5 degrees on your wind correction over a 200-mile leg, you’re going to be miles off course. The CX-3 eliminates that drift.
Common misconceptions about the CX-3
Some people think it’s "cheating." I’ve heard old-school pilots say that if you can't use the manual wheel, you shouldn't be in the cockpit. That’s nonsense. We don't use sextants for navigation anymore, and we don't need to struggle with 1940s slide rules if we have better tools.
Another myth is that it’s hard to update. It actually has a USB port. You can plug it into your computer and update the firmware if ASA releases new features or fixes. That’s pretty sophisticated for a "calculator." It ensures the device stays current with any changes in FAA testing standards.
💡 You might also like: Isaac Newton Explained: What the Legend is Really Best Known For
One thing to watch out for: the screen can be a bit hard to read in direct, high-noon sunlight if you don't have the brightness turned up. But compared to the old LCD screens on the silver Sporty’s computers from ten years ago, the CX-3 is a massive leap forward.
Practical steps for new users
If you just picked up a CX 3 flight computer, don't just toss it in your bag. First, go into the settings and set your favorite units. If you fly a plane that uses Gallons per Hour (GPH), make sure it’s not set to Liters.
Next, practice the "Wind" function until you can do it without thinking. Input: Track, True Airspeed, Wind Direction, and Wind Speed. Output: Heading and Groundspeed. This is the bread and butter of cross-country planning. If you can do this in under 15 seconds, you’re ready for the written exam.
Finally, learn the "Favorite" button. You can bookmark the functions you use most often. This saves you from scrolling through menus while you're trying to fly the airplane. It’s a small detail, but it makes a huge difference in "cockpit management," which is a fancy way of saying "not being overwhelmed while flying."
The Verdict on the CX-3
Is it perfect? No. The buttons can feel a little "clicky" and loud in a quiet testing center. It’s a bit bulky in a pocket. But in terms of reliability and functionality, nothing else really touches it. It bridges the gap between the ancient manual methods and the overly complex iPad apps that do everything for you.
It keeps you involved in the math without making you do the grunt work. That’s the sweet spot for a pilot. You want to understand why the plane is moving that way, but you want the result to be perfect.
Take these steps to master your CX-3:
- Download the digital version first. ASA actually has an online browser-based version and an app. Use the free or cheap version to see if you like the menu logic before dropping $100 on the hardware.
- Verify the firmware. When you get the physical unit, check the version number. If it’s old, use the USB port to get the latest features.
- The "Four-AAA" Rule. Always keep a spare set of four AAA batteries in your flight bag. The CX-3 gives you a warning when the juice is low, but don't tempt fate during a checkride.
- Practice "Reverse" Planning. Use the CX-3 to calculate a flight plan, then double-check it with a manual E6B once or twice. It builds your confidence in the device and keeps your manual skills from getting too rusty.
- Use it for Weight and Balance every single time. Don't eyeball it. Plugging the numbers into the CX-3 takes 60 seconds and gives you a definitive "C.G. is within limits" answer that you can show an examiner with confidence.
The CX 3 flight computer isn't just a gadget; it's a piece of professional equipment. Treat it like one, and it'll probably outlast your first three headsets.