5.A : Preflight Inspection

The student should develop knowledge of the elements related to a comprehensive preflight inspection. The student will understand what to look for during each part of the inspection and have the ability to perform the preflight inspection as required by the checklist and the ACS/PTS.

References : Airplane Flying Handbook (FAA-H-8083-3C, page(s) 2-2ß)

In an aircraft you can’t just "pull over to the side of the road" if a problem is encountered. Prior to flight pilots must make sure that the aircraft is in a safe condition for flight, and any problems that are detected must be addressed prior to flight.

Each aircraft should have a preflight checklist which can be used to insure that all aspects of the aircraft that can be checked prior to flight, are checked. This is generally in Section 4 of the modern standardized POH. Always used the published checklist as it ensures that items are checked, and are generally done so in a logical sequence.

Proceed through the preflight checks without interruption to make sure that no items are missed. If distracted or interrupted, either restart the checklist from the beginning, or go back two or three items and restart. This helps ensure no checklist items are overlooked.

A preflight will logically move around the aircraft to provide an orderly flow of inspections. The preflight actually starts as the pilot walks toward the aircraft with an observation of the general state of the aircraft. Look for any obvious problems, gear out of alignment, structural distortions, skin damage, or dripping fluids. Upon arriving at the aircraft all tie downs, control locks, and chocks should be removed.

Inside the aircraft all required documents should be confirmed as being in the aircraft. It is the pilot’s responsibility to ensure that all inspections have been completed (though note that the aircraft logbooks are generally never in the aircraft itself). Confirm that all required equipment for the flight is available and working in the aircraft. Inspect any cockpit items on the checklist.

Outside the aircraft structural and control items are inspected. This includes skins, struts, landing gear, flight controls, engine, propeller, antennas …​ really, everything. Follow the flow of the checklist looking at each item indicated and confirming safe condition.

When looking at the various components of the aircraft the pilot must understand what they are seeing, and how to identify problems.

Regarding the preflight checks of the fuel it is critical to insure quantity, type, and lack of contamination. The first thing to check is quantity, which should be done visually. There should never be any doubt that adequate quantity of fuel is onboard necessary to complete the flight with safe/legal reserves.

The type/grade of fuel is critical as well. Most piston aircraft use 100LL (AVGAS) which is tinted with a blue dye to aid visual inspection. It should have a characteristic gasoline smell. Jet-A fuel is clear, and has a characteristic kerosene odor. The fuel trucks are also generally clearly marked as to the type of fuel they are dispensing. The incorrect type of fuel will result in a destroyed engine, generally due to a phenomenon known as detonation. If in doubt, drain the tanks and have a mechanic purge the fuel system. Never substitute a lower grade of fuel for the minimum recommended in the aircraft POH. The visual guide to the various grades is :

Finally, it is critical to detect (and remove if possible) any contamination in the fuel. This is generally done by taking a fuel sample from various drain points in the fuel system and visually inspecting the samples. Water is heavier than fuel, and therefore accumulates in the low points of the fuel system, which is where the manufacturer generally places drains. Drain samples from each sump point and look for a "bubble" of water in the bottom of the sample. If detected continue to drain from the various sump points until no water is detected. Also inspect for any sediment or other foreign contamination, similarly draining until all the contamination is removed.

Some operations (at a flying club, or a well-run FBO) maintain a "squawk book" to record issues regarding the aircraft. This document serves multiple purposes, with one being to communicate to the maintenance staff issues discovered in the aircraft. Another function is to inform other pilots of issues regarding the aircraft, and can also serve as a way for maintenance staff to inform pilots that issues have been resolved. Checking for squawks consistently can keep a pilot aware of any problems that may have arisen.

Even small amounts of frost or ice can disrupt airflow over the wing. This will result in an increased stall speed and reduced lift. Remove ALL ice and frost from the airfoils of the aircraft before flight. This can be done by placing the aircraft in a heated hangar, by spraying deicing compounds, or by mechanical removal of the ice/frost.

As the aircraft is loaded ensure that all items are on a proper location and are adequately secured. Verify that the CG limits are honored, and that heavy items can’t move thus altering the CG in flight.

During the preflight process note any discrepancies and make sound judgments as to their impact on the safety of the flight. As PIC the pilot is responsible for the evaluation of the aircraft condition. If in doubt, ask someone with more experience. Never fly if there is some aspect of the aircraft condition with which the pilot is not comfortable.

A safe flight begins with a thorough preflight as prescribed in the airplane’s POH. This preflight inspection ensures the airplane is both airworthy and safe for flight.

To determine that the applicant: