Perfecting Your Preflight Inspection
Maintenance-related problems are one of the deadliest causes of accidents in general aviation (GA). Contributing to this is a pilot’s failure to identify maintenance discrepancies because of a lack of knowledge or improper techniques used during the preflight inspection of the aircraft — red flags that could have been easily discovered and mitigated with more rigorous scrutiny. Enhancing your relationship with your aircraft’s history and your mechanic are both critical components of an advanced preflight and can make the difference between a safe flight and your last flight.
Just How Well Do You Know Your Aircraft?
Advanced preflight is a practice that helps aircraft owners and pilots become more aware of all the safety-related data pertaining to their aircraft. In addition to using the preflight checklist, it focuses on being more cognizant of who maintains your aircraft and how to apply a detailed approach to your preflight inspection based on a review of the aircraft’s maintenance history. The foundation of any effective preflight inspection is knowledge: knowledge of your aircraft’s history, its systems and components, and its propensity for possible failures or vulnerabilities — the sometimes-inconspicuous items not always covered in an Airworthiness Directive (AD) or a manufacturer’s Service Bulletin.
A quality records review is the best way to acquire an intimate knowledge of an aircraft’s maintenance history. You should examine all available resources, including logbooks and records, maintenance manuals, ADs, manufacturer’s service letters, and bulletins, as well as any repair and alteration history. This can take some serious probing, so be sure to ask an AMT, a type club member, or even your local FAASTeam representative if you need assistance.
Once you’ve gathered all of your aircraft’s resources, separate your research into six major groups:
- Airframe records and documents
- Powerplant records and documents
- Propeller records and documents
- Avionics records and documents
- Accessories records and documents (if contained separately)
- AD Compliance records
Organize your documents from each group in numerical date order, starting from oldest to most current. Review one group at a time, starting from the earliest record, reading all pieces of information and documenting:
- Date of all overhauls
- Time of all overhauls
- Overhauling person or organization
- Total time of aircraft at time of overhaul
- If an accessory was installed new or after an overhaul, list the part description, part number, serial number, date, and aircraft time at installation.
To develop your additional items checklist, you’ll want to use your list of information on reoccurring ADs applicable to your aircraft, additional safety-related information you determined you need to inspect during the preflight, any major repairs or alternations, and all inspection times and types.
- Review your Airplane Flight Manual (AFM) or Pilot Operating Handbook (POH) and ensure all required operational information concerning installed or removed Supplemental Type Certificate (STC) items is correct.
- Record your tachometer and/or Hobbs times in order to begin tracking your next AD and inspection times.
- Record the location and type of major repair or alternation complied with on the aircraft; you’ll want to focus additional attention on this area of the aircraft during preflight.
- Record the information regarding the affected item and the recommended inspection for any applicable ADs.
- Document all limitations involving additional installed equipment (e.g., how many vortex generators can be missing before the aircraft is rendered unairworthy).
- Document any information permitting operations without installed equipment from your Type Certificate Data Sheet or keep a hard copy for reference.
- Record a note reminding you to use your hands during the inspection to check for security of installation of the components you are inspecting.
- Add inspection items to your additional items checklist on items you have added for your safety. These items may include over-water required items, fire extinguishing and other personal protective gear, flashlights, first aid kit, and survival equipment if applicable.
Although time-consuming, adding these additional items to your preflight inspections will reduce your risk of an accident and could save you, and your passengers’, lives.
Getting Acquainted with Your AMT
Now that know the details of your aircraft, how familiar are you with your AMT? Part of an advanced preflight is getting to know your AMT and asking questions before a procedure or repair is done to ensure the AMT is qualified and has the proper experience with your type of aircraft or component. Don’t forget that you can always get a second opinion if you’re not completely comfortable with a specific suggestion or mechanical diagnosis. Building a rapport with your AMT will not only help you learn more about your aircraft, but it may also enable you to feel more comfortable with pointing out items that you’re unsure of or believe need corrective action.
Equipped with better knowledge of your aircraft and who is maintaining it, you’re ready for the practical application of an advanced preflight: the walk-around inspection, which is likely your last chance to determine the safe operational condition before a flight. When conducting your inspection, assume that there is something wrong, even if you used the best mechanic. Assuming that everything is good can make it difficult to catch an issue if there is one. Always scrutinize any part of the aircraft that had maintenance performed on it.
Start your inspection with the manufacturer’s checklist if one is available. While most checklists are thorough, they won’t always cover everything you need to examine. So use the checklist to form the basis of your preflight inspection, but don’t limit yourself to it during the inspection. Every aircraft is unique so your preflight should be unique too, there’s no one-size-fits-all when it comes to checklists.
It’s also important to be aware of how vague some checklists can be. The word “check” can indicate several things, so learn what you’re specifically checking for with the item you’re inspecting. For instance, when checking flight control surfaces, the act of checking involves integrating and interpreting visual, aural, and tactile cues. With control surfaces, you’ll want to apply movement with pressure against hinge points while looking for cracks, feeling for looseness or binding, and listening for any abnormal sounds.
During your inspection, don’t forget to use your senses, and a notepad, to write down anything you detect that is not right. Listen to the airplane (not just the engine!). Do you smell anything abnormal? Fuel? Oil? Does it vibrate more than usual (feel)? Do you taste (or smell for that matter) any of that acrid smoke that comes with burning electrical items? Step 10 to 15 feet back from the airplane. Does anything look out of place? Be prepared to abort takeoff if something goes wrong or doesn’t feel right.
Kickstart Good (Advanced) Habits
🛩️ Learn all you can about the maintenance that was performed.
Discuss all work that was done with the mechanic. Ask what to look out and watch for during the first flight. Do not just accept that the work was done. Ask: What was touched, repaired, or replaced, and what was accomplished?
🛩️ Don’t assume the part(s) replaced are the only parts removed.
Ask what was removed and/or disconnected to facilitate the work performed. Often disassembly needs to be done to get to the inoperative part. For example:
- Upholstery/seats, tracks, floors/emergency exits
- Interior and exterior access panels especially in hard-to-see places of the aircraft
- Yokes/control cables, linkages, and surfaces
- Equipment and appliances/wires and connectors
- Hydraulic/vacuum/brake/pitot and static/fuel lines
🛩️ Pay attention to trim positions. Check for unimpeded flight control surface deflections. Make sure they go in the proper direction!
🛩️ Make sure all inspection panels are secure and their fasteners are tight.
Inspect all control fasteners for missing cotter pins. Inspect locknuts, making sure the bolt or stud extends at least the full round or chamfer through the nut. Flat end bolts, studs, or screws should extend at least 1⁄32 inch through the nut. Check all visible bolts. If there’s a hole in the bolt, it requires safety wire in it. See FAA Advisory Circular 43.13–1B, Acceptable Methods, Techniques, and Practices — Aircraft Inspection and Repair, for procedures.
🛩️ Check fuel tank for water, sediment, and proper fuel grade.
Use a sampler cup to drain a small quantity of fuel. Place it in front of a white (not blue) background to see what’s in the fuel. Pull out the strainer drain knob for about four seconds to clear it of water or sediment.
🛩️ After an oil change, always check the engine oil level to ensure it has the proper amount of oil.
🛩️ Always check your logbook and paperwork prior to flight to ensure the correct records have been entered.
Check for proper log entries for the work performed and the return to service, or the aircraft isn’t legal to fly. Always ensure you have your aircraft’s correct documents (e.g., airworthiness certificate and registration) onboard.
🛩️ If you see a warning tag / sign on the aircraft, or on the sign-out or status board, DO NOT FLY THE AIRCRAFT! Check with the maintenance facility prior to taking the aircraft.
🛩️ Participate in, or observe your mechanic perform, an annual or 100-hour inspection.
It’s a great way to learn about your aircraft’s systems, components, and any areas prone to failure or weakness.
Ready to put your preflight prowess to the test? Check out the preflight-in-a-box hands-on exercises being offered at different locations nationwide this month to help you practice the skills of a good preflight. See the seminar links below or search the Seminars & Webinars section of FAASafety.gov.
- Advanced Preflight After Maintenance from faa.gov (PDF download)
- Pilots: Perform Advanced Preflight After Maintenance from ntsb.gov (PDF download)
- FAA’s Advanced Preflight Pamphlet (PDF download)
- Advanced Preflight,” FAA Safety Briefing, Mar/Apr 2012 (PDF download)
- Human Factors: Sometimes it’s the little things — General Aviation News
📅 FAASTeam Events with WINGS Credit (February 2024)
- In-person/Fly-in Seminar 👨✈️ — Feb. 10, 10:00 Eastern, Hilton Head Fire and Rescue HQ, S.C. 🛩️(HXD)
- In-person/Fly-in Seminar 👨✈️ — Feb. 12, 18:30 Central, Chickasha Municipal Airport, Okla. 🛩️(CHK)
- In-person/Fly-in Seminar 👨✈️ — Feb. 17, 9:00 Eastern, Georgetown County Airport, S.C. 🛩️(GGE)
- In-person/Fly-in Seminar 👨✈️ — Feb. 17, 9:00 Mountain, Front Range Flight School, Colo. 🛩️(CFO)
- In-person/Fly-in Seminar 👨✈️ — Feb. 21, 19:00 Eastern, Ithaca Tompkins International Airport, N.Y. 🛩️(ITH)
- In-person/Fly-in Seminar 👨✈️ — Feb. 24, 10:00 Eastern, Ballou Skies Aviation Hangar, Ohio 🛩️(17G)
- In-person/Fly-in Seminar 👨✈️ — Feb. 29, 18:00 Central, Southeast Iowa Regional Airport, Iowa 🛩️(BRL)