We made some small talk after I arrived as I took in the spacious hangar and its contents. The scratched and uneven aluminum skin was obvious from afar.

Tim was apologetic. “Once I got on the slippery slope of rationalizing why I had to have this airplane project, there was no going back. I figured I’d just bring it home and do whatever it needed.”

“No prebuy?” I asked.

Tim gave me a half-smile. “No, the owner said he had to unload it right now. That was four months ago, and he is not returning calls. I can’t find all the paperwork, there are no logs, and I’m missing some parts.”

I wanted to say something else but bit my tongue and took a deep breath. “Okay, let’s look it over, and I’ll do everything in my power to make you successful.”

“Thank you. I know you are coming into it late.”

I got out my notebook and checklists and spent two hours with Tim and Wendy. The first owner had partially assembled the sheet metal aircraft with no prior instruction on riveting. I saw laid-over rivets, rivets driven too much or not enough, missing rivets, elongated holes, and no deburring. Deep scratches trailed off from many of the rivets.

“I’m afraid you will need to disassemble almost everything and get new material from the factory. It won’t be cheap, but if you want an aircraft that is safe for flight, you’ll need to start over. And we’ll need to build you a chain of ownership since your seller did not give you a bill of sale. The manufacturer may be able to help.”

Eventually, Tim and Wendy got their airplane in the air with a happy ever after feeling. But the bite out of their wallet was enormous.

When little things become big things, they can lead to costly traps. Here are the top five, and how to avoid them.

Jumping Into an Aircraft Purchase

Although a second- or thirdhand project purchase is the most fraught with potential troubles, buying any used aircraft should involve upfront research and most certainly a prebuy inspection. Our natural tendency is to rationalize our purchase decision when the excitement is overwhelming. It’s easy to get carried away and assume everything is going to be fine. When the subsequent problem discoveries arrive, the financial shock can be high.

Avoid this dreaded transformation by making a rule for yourself: no aircraft purchases without a thorough review and inspection. You might think that this particular problem is rare. However, I have personally experienced owners telling me they were so happy to find a good deal on an airplane that they didn’t wait, didn’t inspect, didn’t research, and are now spending far more money and time than they thought they would.

Although it’s okay and natural to get caught up in an aircraft purchase, realize this trap awaits the unwary. Do your homework and due diligence first. As disappointed as you might be to reject a deal, later you will realize that it was the smart thing to do.

In addition to a review from someone who knows the airplane, you should also make sure the project carries documentation and paperwork with it. A prebuy inspection will cover these details.

The “No Big Deal” Prop Strike

You may have lived long enough to have one of those moments in which you desperately wished you could have time back. A short rewind, returning you to the previous few minutes before you hit the step stool and toolbox you forgot to put away before taxiing off. You heard the thwack as the prop hit the toolbox, and you heard the engine rpm drop.

You brake the airplane to a stop. Everything feels fine. “No big deal,” you declare. “It was only the edge of the box. How come I didn’t see that back there?” But you are surprised, and now worried, about the possible damage and its consequences. I better look at the prop, you think, as you stop the engine. As you exit the aircraft you really wish you had a few minutes of rewind time. As you see the stool flung up against the hangar door, you look at the damage to the prop tips, hoping for the best. The gouges at the tips look repairable to you, and you once again whisper to yourself, “No big deal. A file will take care of those nicks.”

Since you have a spare prop, you remove the damaged one and install the spare. You are careful now to put the step stool and tools away before taxiing off for your cross-country. No big deal?

A big deal. Of course, you would not have done these things, but I know of someone who did. Six months after the incident, the owner put the aircraft up for sale. On the prebuy, the engine crankshaft runout was out of spec, and further examination indicated that an engine teardown inspection would be required. The sale, of course, fell through.

A little thing became a big thing. Avoid this situation by beefing up your checklist so that you double-check what’s around your airplane before taxiing off, and realizing that there is no such thing as a “minor prop strike.” (See “Prop Strike,” EAA Sport Aviation, March 2018.)

Putting Your Aircraft Away Without Forethought

Whether your aircraft is an ultralight or a jet, the manufacturer has already done the work for you in specifically saying what you should think about if you’re not going to be flying for a while. I’ve seen situations where a pilot was called away unexpectedly between flights, but if the time frame extends out, they are thinking about what extra things they should check before returning the aircraft to service.

More commonly, I see the airplane simply put away to worry about later. Two weeks becomes two months, and then six. When it’s time to pull the airplane out, the auto fuel has congealed in the tanks and carburetor bowls and rust has formed on metals. Corrosion rules. A little thing, like starting the engine, is now a big thing with maintenance ahead.

Avoid this trap by having a rule. When you put the airplane away after a day of flying, ask yourself how long it will be to the next flight. What things should you do now to keep everything happy and running? Have a plan for storage with a checklist.

Weight and Balance Creep

Weight and balance creep can happen in any aircraft. You may have noticed that we usually add accessories to our airplanes rather than remove them. Just as our clothes closets tend to get fuller rather than barer, our homes, cars, and airplanes all seem to accumulate things.

On kit aircraft, weight and balance creep happens as soon as the aircraft goes together. Rarely does the project end up close to the manufacturer’s empty weight estimate. New builders tend to over-engineer the build, especially on composite aircraft. “A little extra resin might be a good idea,” the beginning builder says.

When I began building the Pulsar, my technical counselor clucked his tongue as he looked at my first layups. “I’ll tell you what. Don’t use so much resin. It does not increase strength. If you want a heavy aircraft, you can simply add some bricks to it at the end.”

Where the creep becomes a problem is when we don’t notice it over time. This also happens to certified aircraft, with the addition of accessories. “No big deal,” you say. “This accessory has negligible weight.” We fail to see that they have all added up over time and the weight is no longer “negligible.”

The penalty arrives when we under-calculate weights using the old numbers and then are surprised by handling anomalies. The errors can be high enough to change the center of gravity, leading to accidents. The other small thing that can cause big problems is not bothering to do a simple gut check on loading before a trip with passengers and baggage. How much do these things weigh and where are they going to be located in the aircraft?

Complacency and forgetting to execute the preflight checklist have caused more than one pilot to crash at the end of the runway when unsecured cargo shifted suddenly. This is another example of many small mistakes adding up to serious events.

Winging It on Kit Assembly Instead of Studying Directions

We kit builders do not do these things on purpose; we do heed directions. Sometimes we just make mistakes. When we do, it’s almost always a small item that ends up being a big one. Like the time I worked into the night. After triple-checking the plans, I installed the sump drains in the top of the wings.

I see little problems become big problems when builders think they can do better than the designer and engineer. One builder gave me a call after installing the aileron hinges where they thought they should go rather than where the instructions said they should go. The rework was substantial. In another case, the builder decided to use a different material for the wing ribs over what was specified in the plans. Fortunately, a wing failed before the aircraft entered testing. The rework was long and expensive.

We all make mistakes. We’ve all had the “please rewind” moment. The key to reducing these errors is to take a pause and regroup. As human beings, we assume we are being logical and measured when we may be wildly emotional. While this is our human condition, a pause to think through what we are really going to do will be reinforcing when it’s the right path and open up new avenues if it’s the wrong path.

Get advice from experts. This can be a technical counselor, a friend, a local mechanic or A&P, and other pilots. Go back to the books, the directions, the coursework, or the plans when you feel you are going off on a tangent.

Minimize big surprises on purchases by getting opinions from experts and paying for a prebuy using someone who knows the airplane. This is true on projects as well as flying aircraft.

If, after thinking through a course of action, you realize the project is not the right one, know that you may have avoided big surprises and even bigger expenses. You can then save your time and resources for an even happier and more exciting day getting in the air.

Lisa Turner, EAA Lifetime 509911, is a manufacturing engineer, A&P, EAA technical counselor and flight advisor, and former DAR. She built and flew a Pulsar XP and Kolb Mark III, and is researching her next homebuilt project. Lisa’s third book, Dream Take Flight, details her Pulsar flying adventures and life lessons. Write Lisa at Lisa@DreamTakeFlight.com and learn more at DreamTakeFlight.com.