How To Use An E6B Flight Computer

Have you ever stared down at the E6B flight computer in utter confusion and realized you have no idea how it works? Well, you’re not alone, as this is a common piece of tech that beginner aviators often get wrong.

How To Use An E6B Flight Computer

Today we are going to learn all about this piece of equipment and how it can help you on your flights.

If you’ve never flown before, you may wonder what sort of technology goes into making something like a plane fly. But how about how it can help you plan a flight?

The E6B is a circular slide rule used in aviation and is one of the very few calculating devices still found in the analog format. It was once considered the “gold standard” for aeronautical navigation.

It’s a simple device but there are some rules when using it. You will need to know these if you want to be able to make sense of it while flying.

How To Use An E6B Flight Computer

The E6B flight computer is one of those pieces of technology that can be a real challenge for new pilots.

It’s easy to look at them from the outside and think they are just glorified calculators with circles on them. And that would be true if you only knew how to use them correctly.

In reality, though, they are much more than that and can actually be extremely helpful in planning and executing your next flight. So let’s take a closer look at what they are and how they work.

First Things First: What Are They?

To understand how the E6B works, you first need to understand what it is. These are basically circular slide rules, so they measure angles by sliding along their circumference.

This means that the angle is measured by turning the slide clockwise or counterclockwise.

This is different from most other slide rules which are linear measuring tools.

Linear slide rules are great for measuring distances or lengths, but they aren’t ideal for measuring angles because they don’t allow you to turn the slide.

So why do planes even need these things? Why not just use a regular calculator? Because a normal calculator won’t tell you anything about how far away a certain point is.

That information is important for determining where to go during takeoff and landing.

So instead of having to calculate everything manually, the pilot uses the E6B to determine distance and direct him/her towards the correct location.

History Of The E6B

The E-6B, now commonly known as the E6B, was developed in the US by Lt. Philip Dalton in the late 1930s. He had been working on developing a tool that could replace the manual calculations required for navigating aircraft.

He came up with the idea of using a circular slide rule to solve problems related to navigation. This was a huge step forward in aviation since it meant that pilots didn’t have to carry around bulky paper charts anymore.

Instead, they could simply refer to a digital display, which made their lives easier.

Dalton patented his invention in 1941, and the E-6B became available commercially in 1942. The E-6Bs were manufactured by several companies including the Grumman Corporation.

How Do They Work?

How To Use An E6B Flight Computer

Now that we know what they are, let’s talk about how they work.

When you first open up the E6B, you’ll notice that it has two parts. One part is called the main body and the other is called the cover. The main body contains the actual slide rule itself and the cover holds the batteries.

You can see here that the main body is split into three sections. The top section is where you place the scales and the bottom section is where you place your numbers.

You can see that the scale is divided into four quadrants. Each quadrant represents a specific range of angles. For example, the upper left corner represents 0°-90°, the lower right corner represents 90°-180°, etc.

Once you have placed all of the numbers you wish to use on the slide, you simply slide the main body until it stops. Then you remove the cover and start reading off the results.

To find out the length of a given line segment, you simply read down the number corresponding to the angle between the starting point and the endpoint.

For example, if you were trying to find the distance between points A and B, you would start at the top left scale (0°) and move clockwise until you reach 90°.

At this point, you’d stop and read off the number 90. You then continue moving clockwise until you get to 180°. 

At this point, you stop again and read off the number 180. From there, you simply follow the same process as before until you’ve reached the final point.

If you want to find the area of a triangle, you simply add together the areas of each of its sides. To find the height of a triangle, you subtract the base from the total area.

How To Use A Circular Slide Rule In Aviation

Further to this; a circular slide rule is a type of calculator with a rotating disc rather than buttons or levers. This allows for more accurate calculations and faster results than traditional slide rules.

You might think that they were only used in aviation, but actually, they were widely used until digital calculators became popular in the 1980s.

Circular slide rules work by having two discs: One has numbers printed around its edge (like a clock face) and the other has scales printed along its circumference.

To calculate a number, simply turn the dial so that the scale closest to the number you wish to find matches up with the time displayed on the dial (see also “How Does Heads Up Display Work“).

Final Thoughts

The E6B is a useful tool to have in your pocket when flying. Its compact size makes it easy to store away in a small bag while still being able to quickly access it when required.

It also works well in a pinch – although we wouldn’t recommend using it to do any serious calculations. But it does make a good backup device for those times when you need to do some quick mental math!

Jacob Stern
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