By Lisa Turner, EAA Lifetime 509911
This piece originally ran in Lisa’s Airworthy column in the April 2025 issue of EAA Sport Aviation magazine.
Lauren stood back and admired her handiwork. The garage cabinets would be perfect for the construction of her first airplane. Twelve feet in length, the assembly had cabinets with doors and inside shelving on both ends. A workbench was sandwiched between them with a lighting kit above and storage drawers underneath.
“Wow, that’s a cabinet set all right,” said Sam as he walked into the workshop.
“Now we just need an airplane kit,” Lauren said.
“It’s on its way. What’s this bag of hardware here?” Sam pointed to a bar stool with an unopened plastic bag.
“I have parts left over!”
“The old parts-left-over dilemma. Common practice is to throw them away or dump them into the hardware drawer. It’s not like you’re building an airplane.”
“I will be.”
“Right, okay, I’ll get serious.” Sam looked at the hardware carefully. “This is an anti-tip-over hardware set. It should have been installed before the doors went on the side cabinets.”
“Now you tell me.”
“It’s important. You don’t want this thing falling over on you.”
“I can’t believe I missed that in the instructions.”
“That’s why we have inspection checklists for airplanes.”
Preclose Inspections
If you are building or restoring an airplane, you know details matter. You also know that the order of the details matter. Here are the top mistakes builders make and some tips to smooth the way.
Forgetting About the Extras
How could this happen? Surely, we have a detailed checklist for our restoration or for our homebuilt project. You may be surprised to discover that some things get left off the lists. I visited one project as a technical counselor and asked the builder where the VHF antenna was. It was a composite aircraft, and the tail is a great place to install the vertically oriented antenna.
“Uh-oh.”
We looked closely at the manual, and there was the recommendation to place the VHF antenna inside the structure. By then it was too late. The builder added an antenna externally, but it would have been better to locate it within the composite structure for neatness and appearance. Here are some tips.
- Antenna placement and wiring. Antenna installation details are often overlooked because the manufacturer leaves the decisions about placement up to the builder. If you don’t understand electrical circuits and signal theory (most of us don’t), then you may not understand why bigger is better on a ground plane (the grounded side of the antenna) and why antenna orientation matters. The answer here is to scour the manual before you close up any areas, and get professional help if you need it.
- Pitot and static lines. Verify where these will run and mark them.
- Lighting, accessories, and miscellaneous items. Before you close up sections of your aircraft, check components and placements.
- Custom-built aircraft. Is your project a one-off or original design? If so, spend plenty of time on the precover items and check thoroughly before closing things up. I highly recommend a dedicated precover checklist for your specific project. A starter checklist is included here.
Forgetting About the Routine
Once again, when you have your mind on other assemblies, it’s easy to forget items unless you have a checklist.
- Spare channels for wiring. Every aircraft is different, but they all need safe and easy areas to run wiring and cables. When I ran channels in my airplanes, I underestimated what I would need. Composites are unforgiving; run more channels than you think you’ll need.
- Removable instrument panel. When you wire the back of your panel, I recommend you make the harness long enough so that you can completely remove the panel and flip it for inspections or for repair and upgrade work in the future. Yes, it adds a little weight and cost. But you will decide it was worth it when you have to pull the panel out.
- Electrical bundle ties and clamps. Make sure these are secure and there is no chafing anywhere.
- Cable clamps. Control cables should be arranged for a straight run without binding and securely fastened to structure.
- Fuel and hydraulic lines secured.
- Do bellcranks and push-pull tubes, if you have them, move in the right direction?
- Fabric covered? Make sure there’s no interference with lacing cord in cavities.
Forgetting About the Hardware
- It’s human nature to finish an assembly, mark it off on the list, and move on. Then we put the skins, metal panels, or fabric on and forget to check for correctly placed nuts, bolts, safeties, push-pull rods, and jam nuts.
- Check all controls for full movement. You’ll have a sinking feeling if you forget this and everything is inside, buttoned up, and controls won’t operate stop to stop.
Forgetting Access Panels
- This is less likely because most kits and most plans have these clearly marked. But even on restorations, they can be overlooked. They can be put in later but are harder to install.
- Accidental extras. Even surgeons can leave extraneous stuff in bodies. Make sure you didn’t leave cloths, tools, wires, or anything else inside before enthusiastically closing every panel up.
Missing Corrosion and Defects in a Restoration
Restorations are special animals. Every single one is a little different in terms of what you find when you open it up. This is why pictures and labeling are so important.
One of the items we miss is finding all of the corrosion spots and structural damage in structure. The time to do this is well ahead of precover. Do this when you have the project completely apart. This is also the time to check service bulletins, manufacturer letters, advisories, and airworthiness directives.
Tips for Inspections
- Check with the builders’ and owners’ groups for your specific aircraft. Find out if others will share any inspection checklists with you before you start your own.
- Regardless of the material your aircraft is constructed from, go through the instruction manuals and the plans several times, looking specifically for internal finish inspections, precover inspections, and the detail on wiring and cable routing.
- Restorations should merit this same procedure, although it may be more difficult because you may not have detailed instructions or clear plans. The trick here is in the beginning of your project, rather than the end.
- Inspect section by section rather than all at once.
- Eliminate distractions before you begin any inspection.
- Get other expert eyes on the internals before closing up. Read off your checklist and let them look. An A&P mechanic, fellow builder, or technical counselor is best.
Your homebuilt aircraft kit (or plans) may not have a specific checklist for close-up or precover inspections. This is also true for many restorations. In this case, start your checklist early in the process. Specifically, go through all the procedures and instructions thinking about the details that need to go on the list. This may feel like overkill, but the moment you avoid having to tear fabric off or cut into a composite structure is the moment you will thank yourself for undertaking the time-consuming task of thinking this all the way through.
Lisa Turner, EAA Lifetime 509911/Vintage 724296, is a retired avionics manufacturing engineer, an EAA technical counselor/flight advisor, and A&P mechanic. Lisa has authored six books. Dream Take Flight details her Pulsar building and flying adventures, and For the Love of an Airplane is the biography of Jerry Stadtmiller, a man who restored more than 100 antique aircraft to flying condition. Learn more at DreamTakeFlight.com. Write Lisa at Lisa@DreamTakeFlight.com.