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Preflight precisionPreflight precision

Turn a cursory once-over of the airplane into a proactive safety tool

Your preflight inspection: Simultaneously it is the most important, yet most underappreciated part of any flight. Important because it is your one and only chance to verify that the equipment you rely upon to keep you up in the air is working. Underappreciated because very few pilots give it the attention that they should. Why?

"Most pilots have never been scared into realizing that their lives literally depend on their airplane's performance," said Bob Doohen, director of aircraft maintenance at FlightSafety Academy. "We've become pretty nonchalant about our machines. We just expect them to work flawlessly all the time, and that includes our airplanes."

Matt Thurber, editor of Aviation Maintenance magazine, learned early in his flying career to take advantage of what a good preflight has to offer. "I was a fish spotter spending 12 to 14 hours a day in a Piper Super Cub, [flying] 200 miles offshore," said Thurber, an ATP, CFII, and airframe and powerplant mechanic with inspection authorization. "There was no place to land if I had a problem, so preflights have always been really important to me."

Doohen and Thurber agreed that while most students and private pilots understand the importance of the preflight, many have never been taught how to do it properly. That's the reason Doohen initiated "maintenance briefing" classes for the cadets at FlightSafety Academy in Vero Beach, Florida.

Preflighting 101

Developing the right mindset is key to improving your preflight skills. Thurber believes that most pilots have already mentally "departed" before they begin the preflight. "There is a big difference between the way a pilot and a mechanic preflight an airplane," he explained. "Pilots are optimists -- they are going flying, and nothing is going to get in their way. Mechanics are pessimists -- they approach an airplane thinking about what will they find wrong that will keep them from flying today.

"You almost have to put on a separate hat to do a preflight. Instead of thinking that you don't want to find anything wrong so you can go flying, you need to think that this is your last chance to check the airplane over and make sure it is ready to fly," Thurber continued. "Once you are mentally able to switch gears between the two, you are ready to do a preflight that is going to be much more than just a cursory look at the airplane."

Giving students this "mechanic's perspective" is the goal of Doohen's maintenance briefing courses. "It's a lack of understanding that leads to frustration and cutting corners," he said. "Most pilots just don't really understand what they are looking at and what they should be looking for, so they don't want to waste time doing it. Every pilot should know and understand the major components of the airplane they fly. That way they'll know if something is not right."

You don't have to attend an academy to learn what you need to know about the various systems in order to do a good preflight. The easiest way is to get with your flight school's or FBO's mechanic and ask him or her to walk you through a general review of the various aircraft components and systems so you'll know how to spot a problem.

Until you have a chance to set up your own "maintenance brief," Doohen offered some tips on how you can look like a pro during your next preflight. The first tip is to use the checklist that came with the airplane. You already use it for all other phases of your flight, so why try to commit the preflight to memory?

"A preflight is a visual inspection of the entire airplane," Doohen explained. "But the areas to really concentrate on are the control surfaces, landing gear, engine, and the runup."

Preflighting control surfaces

Everybody gives the ailerons and elevator a cursory push and pull during a preflight. They move; you move on. But do they move in the right direction? Too many accidents have been caused by crossed controls. Also, how do the hinges and connections look?

"As you move the control surfaces, listen carefully to the sound they make," Doohen said. "There really shouldn't be any. If you hear scraping sounds, have a mechanic check it out. There could be too much play in the control cables." (See "Systems Made Simple: In Control," January 2004 AOPA Flight Training.)

When you get to the tail, grab hold of the front of the vertical stabilizer and give it a tug. No, it's not supposed to move. And don't just look at the antennas; give them a gentle nudge to make sure they're on there to stay. Who knows, one may have struck a bird.

While you're doing all this, you're inspecting the leading edges and overall condition of the aircraft's skin for dings, dents, wrinkles, cuts, and the like.

Preflighting landing gear

"The landing gear takes a real beating on any aircraft," Doohen said. "I compare a good landing to jumping off an eight-foot ladder. Do that a few times and your feet, ankles, knees, back, and neck will understand what happens to the gear components and airframe." And that's a "good" landing -- ouch!

What should you check? On a fixed-gear airplane, look at the area where the landing gear attaches to the wing or fuselage. Are there any cracks or deformed areas? Do the tires have the proper inflation, or are there any flat spots? (See "Systems Made Simple: Revere the Gear," p. 50.)

Now step back and look at the way the airplane sits. Is it level on the gear? Does the gear look straight? Thurber shared a story of a student who was preflighting a Cessna 172 and discovered that the previous pilot had apparently landed on the nosegear. "The nosegear was at an odd angle, and we found the firewall was trashed," he said. "If the student hadn't questioned it, there could have been a serious accident."

Preflighting the engine

Rightfully, the engine should get the majority of your preflight attention. The problem is, opening the cowling for inspection is not a realistic option for the majority of training and rental aircraft. But Doohen offers some tips to help you get the most from what you can see.

He suggests using a flashlight to look inside the inlets on either side of the propeller. And please, make sure the mags are off. Always treat the propeller with the respect that it deserves. You only have to move a propeller a couple of inches to get the engine to start if the mags are hot, or if a p-lead -- the wire that grounds a magneto and prevents it from firing -- is broken.

What are you looking for? "Anything that doesn't look right," Doohen said. "Fresh oil, loose wires or connectors, or parts that don't look the way they should." If there's any doubt, ask a mechanic to come see what's up. Next, look down inside the oil filler/access door and up through the nosegear opening under the cowl. While you're down there, give the exhaust pipe a jiggle -- like the stabilizer, it's not supposed to move, although it may be very hot if the airplane just returned from a flight.

If your airplane has cowl flaps, you can look up inside for oil streaming down or parts hanging in there. Being at the bottom of the engine, stuff will gravitate there. Also, take a look on the ground under the engine -- see any parts lying there?

This all may seem all too simple, but the FAA's accident records are filled with reports of pilots missing one of these obvious signs -- only to learn about it after it was too late.

Airworthy versus flyworthy

OK, so the airplane looks mechanically sound and ready to fly. The preflight's done, right? Wrong. "Most students -- and pilots -- don't understand the concept of basic airworthiness," Thurber said. "It's defined right on the airworthiness certificate that's in the airplane. Every student and instructor should take the time to review it, because there are seemingly simple things that can be wrong with an airplane that can make it unairworthy in the eyes of the FAA."

How simple? How about a burned-out landing light, or a frayed seat belt, or a missing shoulder harness clip. You get the idea. "Students just assume it's all OK if their instructor doesn't say anything, but it's not," Thurber said. "Imagine showing up for your flight test and not having an airworthy aircraft. It's a quick way to get shot down."

Have you ever inspected the maintenance logbooks before a flight? "I tell all my students that before they ever fly any airplane they need to look at the logs," Doohen said. "If the FBO won't let you see them and they don't have a good reason, find somewhere else to rent." Why are the logs so important? "They're the only way to know if annuals, airworthiness directives, and other inspections are up to date," he said. Without written proof, there's no way to know if the airplane is in compliance with the federal aviation regulations, he said. (See "What Makes Your Aircraft Legal to Fly?" September 2004 AOPA Flight Training.) Many FBOs don't keep maintenance logbooks at the front desk, but if you suspect something is amiss, ask to see them. Another source of information is the airplane's squawk sheet -- a record of "squawks," or maintenance alerts, made by students and renter pilots.

Preflighting your aircraft's logbooks

What should you look for when you review your aircraft's maintenance logbooks? "Prior to any flight the owner/operator-that means you-must determine that the aircraft is airworthy," said Don Doohen, director of maintenance for FlightSafety Academy. "This should start with reviewing the aircraft logbooks for the following items-and you would be wise to record the information in case you are involved in an FAA ramp inspection." Here are the key areas to examine:

  • Is the aircraft in compliance with required inspections? For a rental aircraft, it would be a hundred-hour inspection-or an annual inspection-in the last 100 hours of operation.

  • Has the aircraft had an annual inspection in the past 12 months?

  • Find the last transponder, encoder, altimeter, and static system checks. They are required every 24 calendar months. The log entry must state that the listed equipment has been inspected in accordance with FAR 91.411 and found to comply with FAR 43 Appendix E.

  • The ELT must be inspected and signed off every 12 calendar months in accordance with FAR 91.207(D). The ELT battery date must also be current.

  • All of the airworthiness directives (ADs) must be complied with. Maintenance personnel are required to make a logbook entry when an AD is complied with, and if it is a recurring AD, they are required to record when the AD is due again.

    For more on the subject, see "What Makes Your Aircraft Legal to Fly?" (September 2004 AOPA Flight Training).

One last chance to preflight

Everything's in compliance, the engine is running, and we're in the run-up area. We're closer to flying, but the detailed preflight isn't done yet. Doohen stressed the need to do the runup without wearing your headset. "It's one of my pet peeves with all students today," he said. "They put their headsets on before startup and keep them on until after shutdown. With a headset on, you'll never know what your engine sounds like."

So, while you're watching for the expected mag drop, lift at least one of the ear cups and listen to the engine. Do you hear anything that may indicate fouled plugs, exhaust leaks, a collapsed flame tube, a stuck valve, or anything else that isn't "right?" It's far better to catch it now than after the runway is behind you.

"If you know what a good engine sounds like, it's easy to spot a bad-running engine," he added. "All you have to do is listen."

A good preflight begins when the last flight is over

Tying down the airplane after a flight is a good time to begin the next preflight. Check it over for signs of a bird strike or any fresh oil or hydraulic leaks. Were you a bit too heavy-footed on the brakes when landing? That could result in a flat spot on a tire. If so, take a look and don't be embarrassed to tell the folks inside the FBO.

"If there is anything about the airplane that doesn't seem right, it's your responsibility to tell the people who operate it -- even if you think it is your doing," Thurber said. "In aviation there are no 'lost points' for bringing up a problem that you may have caused. Not telling someone won't make it go away, and the bottom line is you want to make sure the airplane is safe for the next person who flies it."

Learning how to properly perform a thorough preflight inspection -- and approaching the task from the perspective of a mechanic -- will help you to assure a safe and uneventful flight. Your instructor, perhaps in conjunction with an aircraft mechanic, can help you to reach this level of proficiency.

Dale Smith is an aviation journalist living in Jacksonville, Florida. A private pilot, he has been flying for 28 years.

Want to know more?

Links to additional resources about the topics discussed in this article are available at AOPA Online.

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