H ANDS ON HOMEBUILDER’S HANDBOOK
Here’s a good illustration of attention to detail. This builder did a good job of making sure to tighten jam nuts (and mark with torque seal afterward), and he also remembered to install large-diameter washers on the rod ends to help ensure that they don’t come completely apart should they fail. The only mistake was getting torque seal on the thread of his rod end on the pushrod that comes into the picture from the lower left.
Little Things It all comes down to the details BY JOE NORRIS
ATTENTION TO DETAIL. THAT’S what it finally comes down to. All the little things that go into building an aircraft are what take up much of the time and effort. But it’s those little things that can really set the aircraft apart from the rest, so it pays to spend that time and effort as you work on your project.
This is a good-looking safety wire installation on propeller bolts. In each case, the wire is installed to work against the counterclockwise rotation of the bolt.
90 Sport Aviation April 2011
I want to talk a little bit about the nuts and bolts of building an aircraft, as seen through the eyes of the designated airworthiness representative (DAR). The fact is, a lot of the attention to detail I’m referring to is directly related to actual nuts and bolts! One of the many things a DAR is looking at while performing the airworthiness inspection on a homebuilt is the hardware, things like the proper type of bolt in a particular application, proper application of mechanical safety (cotter pin or safety wire), proper tightening of jam nuts, etc. There are a lot of places on a homebuilt where these items come into play, so there are lots of potential opportunities to miss the details. In my experience, the most often missed of all these details is the tightening of jam nuts on pushrod ends. I’ve found at least one loose jam nut on almost every aircraft I’ve inspected. In one case, every jam nut on the airplane was loose! Make sure to check all the jam nuts after completing your rod end adjustments. This is a great spot to employ torque seal to mark the alignment so you can see if it backs off. This stuff comes in handy
PHOTOGRAPHY BY JOE NORRIS
for both the builder and the inspector. The builder can use torque seal to mark a connection or adjustment that is complete, and when the inspector sees torque seal on the connection, he or she will know that the builder completed the task. (The inspector will check to make sure things are tight anyway!) Take time to watch the Hints for Homebuilders clip on torque seal application (find a link at www. SportAviation.org). Another detail that I often find to be in need of some attention is safety wire installation. I frequently find safety wire that is overtwisted, installed backward (i.e., not in the tightening direction), or just simply not installed at all. There’s a bit of an art as well as science involved in proper installation of safety wire, so a little practice is a good thing. You’ll probably go through a little bit of safety wire before you get the knack, but it’s worth the time and effort. Check out my article “Safetying Nuts and Bolts” in the April 2010 issue of EAA Sport Aviation for more info. You can also find good info on safetying in Chapter 7 of FAA Advisory Circular 43.13-1B, Acceptable Methods, Techniques, and Practices. Speaking of the art of safety wire, one place where this is especially true is when safetying turnbuckles. The proper way to do this isn’t readily apparent, and looking at the illustrations in AC 43.13 Many builders use the “single wrap” method as shown in the top photo. I prefer the “double wrap” method, similar to what’s shown in the bottom photo. Either is acceptable.
PHOTOGRAPHY BY JOE NORRIS AND PAT PANZERA
www.eaa.org 91
H ANDS ON HOMEBUILDER’S HANDBOOK
only goes so far. Take a look at my Hints for Homebuilders video clip on turnbuckle safetying for a good primer on how it’s done (look for a link on www.SportAviation.org). Another detail where spending a little time with the thinking cap on will pay dividends is routing of lines, wires, and cables. Some builders do a pretty good job of this, but many seem to only think about the single system they’re working on and forget about what’s going to come later. You really want the area under your cowling or behind your instrument panel to look like a well-laid-out road map rather than a bowl of spaghetti. Spend some time thinking about the whole project, including continued airworthiness concerns (in other words, how you’re going to access stuff for maintenance) when routing lines, cables, and wires. A little time spent during the construction process will pay you back handsomely down the road. Remember, building an aircraft isn’t one big project. It’s a series of small projects. Spend time thinking about the little things. Joe Norris, EAA Lifetime 113615, is EAA’s homebuilders’ community manager. He is a technical counselor, flight advisor, CFI, A&P-IA mechanic, and a designated airworthiness representative.
AS VITAL AS
VISION
What’s waiting for you out there? Comprehensive in-flight weather data from XM WX Satellite Weather delivers the full scope of your surroundings with radar, lightning, winds aloft and more. Enjoy enhanced situational awareness and efficiency while you fly. Make XM WX a permanent part of your cockpit. And never fly blind again.
w w w. X M W X W E AT H E R . c o m
1 - 8 8 8 - 3 5 5 - 0 1 2 4 8 AM - 5 P M E S T
Hardware and required monthly subscription sold separately. Subscription fee is consumer only. Other fees and taxes, including a one-time activation fee, may apply. All programming fees and weather data are subject to change. XM WX weather data displays and individual product availability vary by hardware equipment. Reception of the XM signal may vary depending on location. Subscriptions subject to Customer Agreement included with the XM Welcome Kit and available at xmradio.com and are available only in the 48 contiguous United States. XM WX is a trademark of XM WX Satellite Radio Inc. The XM WX service is not for “safety for life”, but is merely supplemental and advisory in nature, and therefore cannot be relied upon as safety-critical in connection with any aircraft or other usage. XM is not responsible for accidents resulting from or associated with use of the XM WX Service. Contact XM WX Satellite Radio by phone at 800.985.9200 to subscribe to XM WX Weather. ©2010
92 Sport Aviation April 2011
PHOTOGRAPHY BY JOE NORRIS
