Tunnel Vision: A Tool for Builders

Special-interest and how-to magazines dedicate pages to tools, techniques, new products, and individual success stories, but seldom do I see words dedicated to helping someone get past the mental hurdles. Of course an article about a successful builder is motivational, but that motivation can fade quickly when you’re alone in your shop. In my 20 years supporting homebuilders, I found success is often more mental than the physical manipulation of tools. Not everyone who contacted me needed advice on removing a poorly set rivet or help interpreting plans into parts. Some needed a pep talk. But speaking the words “You’ve got this” without giving them tools to actually “get it” would prove as long-lasting as the homebuilding success stories we read. One of the tools I provided, a tool aviation supply houses don’t sell, a tool that works for me in many areas of my life, is tunnel vision.

Merriam-Webster defines tunnel vision as the “single-minded concentration on one objective.” I call it a building aid. Tunnel vision helps me move forward both when I’m paralyzed by the immense scope of an undertaking and when I’m frozen in place by minutiae. The trick is knowing when to employ it and when to set it aside.

When the Hill Feels Too Steep

The only thing I reach for faster than a pun is an analogy, so here we go. When I’m running or biking uphill I’ve learned to look no more than a foot or two in front of me. That removes the incline from my vision and the effort becomes easier. If I see the grade, it can be psychologically defeating. That technique works in homebuilding as well. When the next page in the plans has more ink than white space it’s all too easy to focus on the whole of it. It can delay taking action on the next step, and that is the first step in a project becoming abandoned. Just as uphill runs are accomplished one step at a time, and complex algebraic expressions are completed one operation at a time (an analogy within an analogy!), so too are complex (and simple) aircraft parts and assemblies.

The roadblock may be a part that needs to be bent or welded or wings that need to be rigged. None of those tasks, as a whole, can be defined by a single action. Bending a part is a series of simple tasks—all of them accomplished before the part is actually bent. Welding is a series of tasks—all of them accomplished before the part is welded. If welding worries you, you can move forward by making the individual parts and the fixture and then have them welded by a friend or a professional. To keep your project moving you need only block out the big picture and focus on the one next thing you can accomplish: a drilled hole, a filed edge, laying out a part on raw material, etc.

Mired in Minutiae

Tunnel vision becomes an enemy when we become too focused on the results we are (or aren’t) achieving. I found a common sticking point for builders was fretting over dimensions and angles. This happened to me not so long ago when I mated the forward fuselage of my Onex to the aft fuselage. I employed a digital level to square the front to the back and spent hours, spread over days, chasing fractions of a degree. I began questioning both the parts and my skills. I had done this procedure before, when I built my Sonex; similar subassemblies, similar procedure. So why the struggle? The difference, I realized, was when I built my Sonex in 2001 I used bubble levels, not digital levels. I put the digital level away and employed a bubble level on my Onex and progress began anew. (What’s more, I found the digital level could display angles to a more precise value than it could measure them. What’s the point of that?)

So how do you know when tunnel vision has you stuck? My advice is to gauge your results against common sense. (Oxford Languages defines common sense as “good sense and sound judgment in practical matters.”) For instance, when squaring Sonex wings to the fuselage a reference dimension is taken from the vertical stabilizer tail post channel to the outer aft tip of each wing. That dimension is defined as 5/32 inch greater on the left side. Builders would fret, at length (I warned you of my affinity for puns), over achieving the 5/32-inch difference precisely. It’s a dimension that’s difficult to measure precisely with a tape measure, which is the only reasonable method available to measure those distances. So it was my job to convince them the goal wasn’t to achieve exactly 5/32 inch difference, it was to square the wings to the fuselage. Being off 1/2 inch was a difference that required action; being off 1/16 inch from the 5/32-inch target had no bearing whatsoever on how the aircraft would fly.

Reaming a bearing to 0.125 inch when the plans call for 0.115 inch is a significant error, which will introduce play into a rotating assembly. Bending a part to 93° when the plans call for 91.7° is going to be acceptable in 99% of applications. Bending to 96° is not. Having 26° of maximum flap extension when the plans call for 30° is going to be acceptable on any homebuilt I can think of. Landing scenarios are so dynamic that no one can convince me that an additional 3° would make a difference.

I’m not advocating for builders to take shortcuts or accept less than they are capable of, but, as someone who has dedicated too many hours of my life to the pursuit of perfection, I am giving everyone (including myself) permission to move forward with a common-sense perspective. While it’s impossible to teach common sense, I have two filters through which one can gauge whether they are frozen in place by dimensional tunnel vision. The first is to ask how critical a dimension or angle may be. The second is to convert the difference between your results and the defined dimension into a percentage of deviation. Reaming a hole to 0.125 inch instead of 0.115 is an error of 8.6%. Not only is that a large percentage deviation, reaming is a dimensionally critical operation with negative results if done poorly. Conversely, if you are tasked with cutting a longeron to 87 9/32 inches and you come up 1/32 inch short you’ve done no harm whatsoever and the percentage of deviation is miniscule.

Frame Your Project for Success

To increase your chance of success, frame the project in your mind as a series of thousands of separate projects. Reduce the “single-minded concentration on one objective” to completing individual tasks, not to completing the aircraft. In conversations with others, by all means tell them you’re building an airplane. After all, a finished airplane is the objective. No one ever says “I’m building two wings and part of a fuselage to store in my garage,” though that is exactly what can happen when you overwhelm yourself with everything left to do rather than focus on the next hole to be drilled, the next edge to be deburred, or the next wire to route to the power bus.

Tunnel vision is a tool you can employ when your project has you feeling overwhelmed, discouraged, or stuck. It reduces a multiyear project down to the next 10 minutes. But it’s also important to recognize when tunnel vision has you frozen in place, fretting over a detail that is insignificant in the overall scope of the project.