Commercial pilot · ACS CA.II.A · lesson pack

Preflight Assessment

Why this one matters

A commercial pilot is often flying someone else's airplane, on someone else's schedule, with people who assume it's been checked. Fuel contamination, a gear or propeller defect, frost, or a tired pilot are all found on the ramp or not at all. The professional preflight is the one that's done fully even when the client is waiting.

1 · Know these cold

•Before every flight, assess the pilot, the aircraft, the environment and the external pressures (PAVE); for a commercial flight, the pressure to complete the job is part of the assessment.(Risk Management Handbook (FAA-H-8083-2A))
•The pilot in command decides whether the airplane is in condition for safe flight, whoever is paying for the flight.(14 CFR 91.7)
•Use the POH checklist for the walkaround every time, and know why each item is checked and what a defect looks like.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
•In a complex airplane, look at the retractable gear (tires, struts, actuators, doors, squat switch) and the constant-speed propeller (blades, hub, oil leaks) as carefully as the fuel.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Complex Airplanes)
•The airplane must conform to its type design: placards and markings in place, no unapproved modifications, required documents on board.(14 CFR 91.9, 91.203)
•Remove all frost, ice and snow from wings, tail and control surfaces before takeoff.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C))
•Keep assessing the weather, terrain, airports and airspace through the flight, not only at the airplane.(Commercial Pilot ACS (FAA-S-ACS-7B), CA.II.A.S4)

2 · The lesson

The pilot

Run IMSAFE honestly: Illness, Medication, Stress, Alcohol, Fatigue, Emotion (eat and drink well too, but that isn't part of the acronym). Alcohol has hard limits: not within 8 hours of drinking, not under the influence, not at 0.04 or more (91.17). Duty days and early starts make fatigue the usual commercial threat.(Risk Management Handbook (FAA-H-8083-2A); 14 CFR 91.17)
Hold personal minimums for weather, wind and your recent experience in this airplane, and decide by them before you arrive at the airplane.(Risk Management Handbook (FAA-H-8083-2A))
Don't act as PIC or a required crewmember with a known condition, or while taking medication for it, that would make you unable to meet the medical standards for the certificate you're using.(14 CFR 61.53)

The right airplane, airworthy

Is this airplane right for the flight: performance, range, equipment for the conditions, and your experience in its systems?(Risk Management Handbook (FAA-H-8083-2A))
Documents on board: the airworthiness certificate (displayed) and the registration (91.203), plus the approved flight manual, markings and placards, and current weight and balance (91.9).(14 CFR 91.9, 91.203)
In the maintenance records (not the cabin), with return-to-service entries: the annual, the 100-hour when it applies, AD compliance, the ELT (12 calendar months), the transponder (24 calendar months), the altimeter, static system and altitude reporting (24 calendar months, for IFR) and the VOR check (30 days, for IFR). The owner or operator keeps those records (91.417).(14 CFR 91.207, 91.409, 91.411, 91.413, 91.171, 91.417)
Inoperative equipment, without an MEL: if it is required by the VFR-day type certificate, the equipment list or kinds-of-operation list, 91.205 or another rule for this flight, or an AD, you don't go. Otherwise remove it, or deactivate it and placard it "Inoperative", with a maintenance record, and a pilot or mechanic decides it isn't a hazard. With an MEL, follow it.(14 CFR 91.213)
The 100-hour inspection applies when the airplane carries any person other than a crewmember for hire, or when the person giving flight instruction for hire provides the airplane (not when the student provides it). An annual counts as a 100-hour only if it was done within the last 100 hours. The limit may be exceeded by up to 10 hours only to reach a place where the inspection can be done (not to carry passengers for hire on the way), and the overage comes off the next 100.(14 CFR 91.409(b))

The walkaround

Follow the POH checklist in order; it's designed to walk around the airplane once without missing anything.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
Fuel: check the quantity visually or with a dipstick (never the gauges alone), and sump every drain into a clear sampler for water, sediment and the wrong fuel. Color is only a clue (100LL blue, 100 green, Jet A clear to straw; mixed fuel loses its color): confirm the grade by the placard, the fuel order and the truck or pump marking. If the sample looks wrong, don't fly.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
Landing gear on a retractable airplane: tires, struts at the right extension, hydraulic lines, actuators and gear doors secure, and the gear area free of debris.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Complex Airplanes)
Constant-speed propeller: blades free of nicks and cracks, no oil streaks from the hub, spinner secure.(Airplane Flying Handbook (FAA-H-8083-3C), Transition to Complex Airplanes)
Controls, hinges and attach points, pitot cover off, static ports and fuel vents clear, stall warning working; cowling and oil secure.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
The regulations: you're responsible for the airplane's condition for safe flight, and it must meet its type design with required placards and markings.(14 CFR 91.7, 91.9)

Environment, pressures and security

Weather, terrain, route and obstructions, plus the airports (runway length, NOTAMs, services) and airspace you'll use.(Commercial Pilot ACS (FAA-S-ACS-7B), CA.II.A.S4)
External pressures: the client, the schedule, the money already spent. Name them out loud, and make the no-go call on safety alone.(Risk Management Handbook (FAA-H-8083-2A))
Security: lock the airplane, secure the keys, look for tampering, and report suspicious activity to airport management or 1-866-GA-SECURE.(TSA General Aviation Security; AOPA Airport Watch)

Want it all on one page, with scenarios? Read the full lesson.

On the flight

ACS standards

Inspect the airplane with an appropriate checklist; verify it is in condition for safe flight and conforms to its type design.(Commercial Pilot ACS (FAA-S-ACS-7B), CA.II.A.S1-S2)
Perform a self-assessment, and continue to assess the environment for safe flight.(Commercial Pilot ACS (FAA-S-ACS-7B), CA.II.A.S3-S4)

What your instructor is watching for

Your instructor watches for a checklist-driven walkaround done thoroughly, real attention to the gear and propeller on a complex airplane, a correct airworthiness and inspection review, and an honest self-assessment.

3 · Say it out loud

Answer each one out loud, then check yourself and mark how it went.

Remember Recall it
“When does an airplane need a 100-hour inspection?”
Understand Explain why
“Why are external pressures a bigger risk on a commercial flight?”
Apply Use it on a flight
“Your client is waiting and you find an oil streak running back from the propeller hub. What do you do?”

4 · Common mistakes

Shortening the walkaround because the airplane flew earlier today.
Things change between flights, and the last pilot may have missed something.
Instead: Do the full checklist every time; you're the pilot in command now.
Checking the annual but forgetting the 100-hour when flying for hire.
Carrying passengers for hire requires it.
Instead: Review both inspections, and the hours since, before any commercial flight.
Letting the client's schedule decide.
External pressure is behind many accidents.
Instead: Set go/no-go criteria in advance and say them out loud.

5 · Quick check

Answer, then reveal. Flag anything you want to see again.

1. Who determines whether the airplane is in condition for safe flight?
2. What does PAVE stand for?
3. Which inspections do you check before carrying passengers for hire?
4. What do you look for on a constant-speed propeller during the walkaround?
Scenario5. Light frost is on the wings and your passengers are boarding. What do you do?

Trained it? Now prove it: practice preflight assessment out loud with our examiner.

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Connect it

One situation that runs across this lesson and its neighbors in the same ACS area. Decide first, then check.

Connect it · Preflight Procedures

A retractable-gear airplane with a constant-speed propeller. During preflight you find fresh hydraulic fluid near the nose gear. Three passengers are boarding.

How do the preflight finding, the passenger briefing and the before-takeoff check connect? Decide, then see the worked answer

Stop the boarding and keep the passengers clear of the airplane until a mechanic has inspected the fresh fluid near the gear and you, as PIC, have determined the airplane is airworthy. A failed gear system changes every landing. Once it's cleared, review the POH emergency gear-extension procedure before departure: a check on the ground proves only that the gear is down and indicating down now. Brief the passengers as 91.107 requires: how to fasten and unfasten their seat belts and, where installed, shoulder harnesses, and that they must be fastened for movement on the surface, takeoff and landing. Add the exits and emergency equipment. Confirm the down-and-locked indications in the preflight, and check them again before takeoff per the POH. The run-up is for cycling the propeller and checking the engine instruments; it tells you nothing about how the gear will work in flight.

AFH (FAA-H-8083-3C), Transition to Complex Airplanes; 14 CFR 91.7, 91.107

Brings together: Preflight Assessment · Flight Deck Management · Before Takeoff Check

Teaching this? The instructor lesson plan →

Study aid, not FAA guidance. Sources: Airplane Flying Handbook (FAA-H-8083-3C); Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C); Risk Management Handbook (FAA-H-8083-2A); Commercial Pilot ACS (FAA-S-ACS-7B); Your airplane's POH/AFM; 14 CFR 61.53, 91.7, 91.9, 91.203, 91.213, 91.409. Checked against current sources 2026-11-13.