Sometimes called the walk-around, the Cessna 172 preflight checklist is the initial inspection a pilot makes of the aircraft right before they take it flying.
It’s a vital safety check to ensure that that plane is airworthy–that is, it has everything it legally needs to fly and is in good condition to do so.
Most pilots conduct the walk-around in three separate phases.
- Initial cockpit check and quick walk-around to check the lights (master switch on)
- Detailed walk-around inspection (master switch off)
- Final walk-around before departure (more on this one in the tips section)
As you become a pilot, the preflight checklist is one of the first things you’ll learn. This guide will help you master it quickly.
What is the Purpose of a Preflight?
Most airplanes are very well-maintained. To meet FAA regulations, a mechanic must thoroughly inspect the plane at least once a year.
But the planes you train in or rent will likely be inspected more often, every 100 hours. So why is the preflight so important?
To put it simply, planes break–a lot.
Think of all those student pilot landings your trainer has survived. And those countless hours in the air, with its engine running at more than 80 percent power.
Airplanes are complex, to begin with, and they are roughly used. All of this takes its toll.
Plus, stuff happens.
Vibrations loosen screws, corrosion takes its toll on metal parts, mechanics accidentally rig the flight controls backward, fuel caps don’t get closed and let rain in, line personnel put in Jet A fuel in a moment of distraction–the list goes on and on.
The smallest things can make a big difference when you are 3,000 feet in the air and 20 miles from the nearest airport.
All of this adds up to the fact that a careful and thorough preflight is one of the biggest things you can do to mitigate risk during a flight.
A preflight assures you that the plane is in good shape, which goes far beyond the legal definition of “airworthy.”
6 Tips for Preflighting the Cessna 172
Here’s a list of tips to keep in mind when preflighting your plane. For a close look at the walk-around process, check out our Cessna 172 preflight video above.
A Preflight Begins the Moment You See the Plane
Preflights are all about inspecting things and being observant.
When you start, you’ll focus on the individual tasks that your instructor teaches you from the checklist.
But the idea of a Cessna 172 preflight checklist is much more than that–it’s the act of looking at the plane closely and observing differences. So what has changed since the last time you flew, and why?
The preflight encompasses much more than the 172 checklist says it does.
For example, if the last pilot left the windscreen smeared with bug guts, you must clean it. You can’t spot other planes in the air without a clean windscreen!
Details like this are seldom on the checklist but are nonetheless very important.
To that end, get out of the mindset that a preflight is limited to a few items on the checklist. Look your plane up and down from the moment you walk up to it on the ramp. That’s when a preflight really starts.
Don’t be Rough
Too many students grab the flight controls and mash them to their stops.
This is very rough on the linkages and cables, plus it can actually warp the skin of the plane. Another example is when you slam the doors instead of activating the latches with care.
Yes, it will probably be fine, and yes, it is a rental.
But it’s also your airplane for the day, and there’s no need to beat it up. Take care of your plane, and it will take care of you. Plus, less frequent replacements mean your school can keep the rental costs down!
Triple-Check the Fuel Visually
Fuel is a big deal.
Your engine needs a constant supply of pure, clean fuel to run. Nearly all engine failure incidents are tied to fuel starvation or fuel contamination.
Therefore, it only makes sense to be as careful as possible when checking your fuel’s quantity and quality.
Quantity is checked visually by seeing it at the top or bottom of the filler neck.
You know how many gallons are in the tank at those two points. Anywhere else, and you don’t know. If it’s below the filler neck, the only way to know is to use a straw-style calibrated fuel gauge.
Never take off if you can’t visually confirm precisely how many gallons are on board. And never trust the plane’s fuel gauges for this purpose–they can be inaccurate.
Quality is checked by taking sump samples from each of the 13 fuel sumps on the 172. Check the fuel is indeed 100LL by color and scent. Make sure there is no water present, and if there is, drain it out completely.
Know What Keeps Things Together
Despite their complicated designs and space-age looks, planes aren’t that complicated or magical.
They are held together with nuts and bolts. Make sure those nuts and bolts are there!
That means knowing which ones you can visually check and what they look like. If you see a castellated nut, ensure it has a cotter pin (like on the elevator trim tab).
If a nyloc nut (sometimes called an elastic stop nut) is used, make sure you can see three full threads of the bolt showing.
Do a Final Walk-Around
Have you ever heard the saying, “Don’t miss the forest for the trees”?
It means that by focusing on the individual trees, you can’t appreciate the beauty of the forest as a whole. This applies to Cessna 172 preflights, too. You’re taught to look at little things–nuts and bolts, fuel samples, paperwork–and all of that can make you forget to open your eyes and be observant.
The final walk-around is about stepping back from the plane and taking a final look at your plane from a distance.
Is it sitting level? Are the tires equal? Are both flaps extended the same? Did you put the fuel caps back on and close the oil compartment?
Are there any mysterious puddles under the plane? Have you untied all three tie-downs? Don’t laugh–a final walk-around can save you some serious embarrassment on the ramp.
If You Aren’t Sure, Ask
Finally, remember that it takes many hours of flying and many Cessna 172 preflight checklists to become an expert.
Few pilots can claim to have seen it all. Ask your flight instructor if you aren’t sure how something is supposed to look or if something is wrong. When in doubt, don’t go.
A good starting guide to preflights is the FAA’s Airplane Flying Handbook, Chapter 2: Ground Operations.