2.preflight-inspection. Preflight Inspection
The preflight inspection is a methodical, systematic visual examination of the airplane to determine that it is in a safe and airworthy condition for the intended flight. It is the pilot in command's first opportunity to discover discrepancies that, if left undetected, could lead to in-flight emergencies. The Airplane Flying Handbook emphasizes that the preflight is not a casual walk-around — it is a disciplined procedure performed using the manufacturer's checklist found in the Pilot's Operating Handbook (POH) or Airplane Flight Manual (AFM).
Document Check. Before walking out to the airplane, the pilot verifies that the required documents are aboard. The acronym ARROW is commonly used:
- Airworthiness certificate (FAA Form 8100-2), displayed where legible to occupants
- Registration certificate (FAA Form 8050-3)
- Radio station license (only for international operations under FCC rules)
- Operating limitations (POH/AFM, placards, markings)
- Weight and balance data, current for the airplane
The pilot also reviews the maintenance logbooks to confirm currency of required inspections — annual, 100-hour (if operated for hire or for flight instruction in a rental), transponder (24 calendar months), pitot-static and altimeter (24 calendar months for IFR), ELT battery, and any Airworthiness Directives (ADs).
Cabin Check. Inside the cockpit, the pilot confirms control wheel lock removed, ignition OFF, master switch ON momentarily to check fuel gauges and lower flaps, then master OFF. The pilot verifies required equipment is operational and that loose articles are secured. Seat tracks, seat belts, and shoulder harnesses are inspected for damage and proper latching.
Exterior Walk-Around. The walk-around is performed in a consistent direction (most POHs prescribe counterclockwise starting at the cabin door) so that no item is skipped. Typical items include:
- Fuselage and empennage: skin condition, antennas secure, static ports unobstructed, tail tiedown removed, control surface hinges and stops, trim tab condition, and free movement.
- Wings: leading edge for dents and bird strikes, fuel tank caps secure and vented, fuel quantity verified visually, sumps drained for water and contaminants, stall warning vane or port operative, pitot tube cover removed and pitot heat checked, fuel vents clear.
- Landing gear: tire condition (cuts, wear, proper inflation), brake pads and lines for leaks, struts properly extended, wheel chocks and tiedowns removed.
- Powerplant: cowl fasteners secure, oil level (typically minimum 6 quarts in a Cessna 172, full to 8 for cross-country), oil and fuel leaks, induction air filter clean, exhaust stack security and cracks, propeller for nicks (especially on the leading edge), spinner secure, alternator belt tension.
- Fuel sumps: drain each sump (wing tanks and gascolator) into a clear cup, checking for water (will bead and settle), sediment, and proper color/smell. 100LL is dyed blue; jet fuel is clear/straw-colored. After heavy rain, sustained ramp time, or refueling, allow fuel to settle several minutes before sampling.
Fuel Quantity and Quality. Pilots must visually verify fuel quantity rather than relying solely on cockpit gauges, which 14 CFR 23 only requires to read accurately at zero. Confirm the correct grade (100LL is the most common avgas) — misfueling with jet fuel is a serious hazard, particularly for piston aircraft serviced on jet ramps.
Special Conditions.
- Cold weather: confirm all frost, snow, and ice are removed from wings, tail, and control surfaces. Even a thin layer of frost can disrupt airflow and reduce lift by up to 30 percent and increase stall speed. Check for water in fuel from condensation.
- Hot weather/high density altitude: anticipate degraded performance and verify takeoff data accordingly.
- After maintenance: inspect for tools left behind, loose hardware, safety wire, and ensure cowl/inspection panels are properly secured.
- Dual-pilot or rental aircraft: never assume the previous pilot left the airplane airworthy.
Use of the Checklist. The FAA stresses read-and-do for unfamiliar airplanes and do-and-verify (flow then checklist) for experienced pilots, but in either case the printed checklist is the authoritative reference. Reciting from memory is not acceptable for ground operations.
Discrepancies. If a discrepancy is found, the pilot must determine whether it affects airworthiness. Required equipment is established by 14 CFR 91.205, the equipment list, the Kinds of Operations Equipment List (KOEL), and any applicable Minimum Equipment List (MEL). Inoperative equipment that is not required may be deactivated, placarded INOPERATIVE, and logged in accordance with 14 CFR 91.213(d). Items affecting safety of flight ground the airplane until repaired and signed off by appropriately certificated maintenance personnel.
A disciplined preflight inspection — the same way every time, using the checklist, with no shortcuts — is the foundation of safe ground and flight operations.