top of page
Below is a sample chapter from my book, Mullane's Guide to Learning to Fly: Deep Dives into Select Topics for Today's Student Pilot
Click here to see a full list of chapters and topics covered

Click here to purchase the book at Amazon.

Click here to purchase a signed copy.

Copyright 2023 Patrick Mullane, All Rights Reserved

From Chapter 2: I'll Take the Beginner Package

And now for some controversy …

The E6B is a rectangular slide rule device with a circular slider that allows an aviator to make all sorts of useful calculations before and during a flight. It will tell you the distance flown given a ground speed and time. It will tell you what direction to point the nose of the airplane to correct for wind pushing you off course. It can even do unit conversions. It can do these and many, many more functions. Its versatility is amazing when you consider that the original E6B came into existence in the late 1930s thanks to the work of an enterprising navy lieutenant and aviator named Philip Dalton. 

I found a picture of Dalton at about 30 years old, and he looks like the sort of guy who would invent a flight computer. With large ears and a pronounced nose, he fits the visual stereotype of a nerd quite well. And I say that with adoration and a sense of comradery. I fancy myself a nerd. My undergraduate degree is in mathematics; I stood in line for hours the week the first iPhone was released to purchase the revolutionary device; I had a Commodore 64 computer shortly after its release in 1983 and learned to program in BASIC on the 64K machine; I had a large collection of Star Wars action figures adorning the shelves of my late-teen bedroom. My nerd credentials are stout. So, I consider Dalton a brother from another mother.

Dalton was clearly a bright guy. He studied physics at Cornell, got his master’s degree in the same subject at Princeton, and then secured a PhD at Harvard, where his thesis was on the topic of artillery fire control, a subject that I suspect has not been studied at Harvard since. Improving on his own original invention, Dalton eventually had a sellable product that he called the “Dalton Aerial Dead Reckoning Slide Rule Model B.” Eventually, the device got its current, more famous (at least in the aviation community) name from the Army; E6B is nothing more than a government part number. That said, many ardent fans reject this sterile name, instead calling it the “whiz wheel.” It’s unclear to me if the name refers to the E6B itself or is some sort of self-congratulatory moniker for the user of the device who might fancy himself or herself a “whiz” for mastering its many functions. The passion about the E6B and the pride demonstrated by those zealots who use it makes me suspect the latter.

It’s a testament to Dalton that a device he invented about 30 years after the Wright Brothers first flew was being purchased by me 81 years after his death. I can’t think of another instance of such longevity for a manual device that does what an app on a phone can do faster and more accurately. 

Yes, the E6B is the Swiss Army Knife of the analog aviation world, performing its myriad functions without a single microchip or battery. But there are a million inventions from years ago that we don’t hold onto as we have the E6B when more convenient and accurate alternatives come along. Do you use a slide rule to calculate the square footage of your living room? I doubt it. Do you take an abacus to the grocery store? Do you carry leeches with you on business trips in case you find yourself not feeling well?

You can’t even make the argument that the E6B teaches you the math of the calculations it performs. It doesn’t. Remember, it’s a computer, although not an electronic one. It does the work for you. 

“But it never runs out of power” is a common retort from those who disagree with me, noting that any alternative to the E6B like a mobile phone app, an electronic flight bag (EFB) application, or a standalone E6B electronic calculator relies on batteries. To that I say, “so what?” I have an electronic E6B app on my iPhone and two iPads I carry when I fly. Are all three of them going to run out of power at the same time? To those who might suggest it’s indeed a possibility, I’d point out that my triple redundancy in flight computation is more robust than the redundancy in many aircraft systems that are much more critical to safety. Yet we happily hop into our general aviation (GA) planes anyway. 

It’s also important to note that while I reference EFBs (like ForeFlight or Garmin Pilot) as substitutes for the E6B, those amazing applications don’t even require you to do discreet calculations in the same way you might on a manual or electronic E6B. They do all the necessary computations behind the scenes seamlessly, allowing you to do a preflight plan more accurately and safely and, most importantly, make in-flight changes very easily in a much less distracting way with fewer inputs. In fact, since getting my private pilot certificate, I’ve not used an E6B once.


At the risk of belaboring the point, imagine an alternate universe where Dalton never created the E6B back in the 1930s. In a world where the manual slide rule never existed, anybody who started training sometime in the last decade would have gone through that training using electronic devices to do preflight planning and in-flight calculations. New pilots would never have known the joys of spinning the whiz wheel. Then, one day in our alternate universe, you’re sitting in the bathroom, flipping through a Sporty’s catalog (don’t roll your eyes, you know you do it) and see a full-page ad touting a new, manual flight calculation device, $35 for a metal one and $15 dollars for a plastic one. It’s less accurate than the electronic alternatives you’ve been using. It’s hard to read the numbers on it. It will take a while to learn how to use it. It’s difficult to use in flight. But good news: you’ll have it in case everything you own runs out of power. Would you buy it? No, you wouldn’t. The fact is that if Dalton had had access to an electronic computer of the kind we know today when he was at Cornell in the early part of the twentieth century, he would never have designed the E6B as a slide rule. It would have been an app represented by an icon on your phone.

You can tell by the way I started the discussion of the E6B that I knew I was wandering into touchy territory by insinuating that the manual version is a waste of (admittedly not too much) money. Indeed, it’s uncomfortable for me to talk about the “E6B question” after just spending so much effort writing about the wonders of the tight-knit aviation community. But with respect to the E6B, it’s as if we are a great religion where, like a lot of religions, a schism formed that separated one faction from another and created a world where compromise is just not possible. 

I’m not going to do much to bridge that divide here. To those who love the whiz wheel, good for you. Go crazy spinning your wheel, marking your dots, sliding your rule, and reading your answer in three-point font. Take pride in your ability to use it as you might in your ability to operate a rotary phone or a toilet with a flush pull-handle mounted from a box above the commode. But don’t try to convince the rest of us, especially those new, impressionable student pilots, you must learn how to use it. You don’t.

Click here to purchase the book at Amazon.
Click here to purchase a signed copy.

bottom of page