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Commercial pilot · ACS CA.I.F · lesson pack

Performance and Limitations (Commercial)

Why this one matters

Commercial pilots fly heavier, faster airplanes with paying passengers and their bags, often from unfamiliar runways. Most performance accidents come from trusting the book number without margin, or loading the airplane past a limit because the runway looked long enough. Knowing the gap between calculated and actual performance is the protection.

1 · Know these cold

  • •Use the POH charts for takeoff, climb, cruise, landing and weight and balance. Read every note: wind, slope, surface and technique corrections.(Your airplane's POH/AFM)
  • •Density altitude is pressure altitude corrected for nonstandard temperature; humidity raises it a little more. Thinner air means less lift, less engine power and less propeller thrust: longer takeoff, weaker climb, and a higher true airspeed and groundspeed for the same indicated.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • •Book numbers come from a new airplane in good condition, flown with average piloting skill in normal conditions. After every POH correction, many pilots add their own margin (a common rule of thumb is 50%) to takeoff and landing; it is a personal rule, not an FAA requirement.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • •Weight and center of gravity are separate limits. An aft CG reduces stability and stall/spin recovery; a forward CG raises stall speed and needs more elevator.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • •Maneuvering speed (VA) protects against one full, abrupt deflection of one control in one axis, not combined, repeated or reversing inputs, and not every gust. It falls with weight: VA × √(actual weight ÷ gross weight), or the POH table.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aerodynamics of Flight)
  • •Load factor increases in turns: 60° of bank is 2 G, and stall speed rises by about 41%.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aerodynamics of Flight)
  • •Never exceed a limitation in the POH/AFM: speeds, weights, CG range, load factors.(14 CFR 91.9)

2 · The lesson

Charts and data
  • Charts come as tables and graphs. Interpolate between lines, never extrapolate past them, and read the conditions they assume: weight, flaps, paved dry runway, technique.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • A graph, in order: enter at the outside air temperature, go up to the pressure altitude line, across to the reference line, follow the guide lines for weight, then for wind, then read the distance; apply the notes for surface and slope last.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • 91.103 makes this a duty: before every flight, know the runway lengths and the takeoff and landing distances for the expected conditions.(14 CFR 91.103(b))
  • Compute takeoff and landing distances over a 50-foot obstacle, not just ground roll, when obstacles are near.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
What changes performance
  • Atmosphere: density altitude (altitude, temperature, humidity). Runway: slope, surface (grass, wet), wind.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • Configuration: the POH flap setting and gear position for each phase. Landing traps: more flaps than the chart assumes changes the numbers, and a fast or long approach can double the landing distance.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance; Airplane Flying Handbook (FAA-H-8083-3C))
  • Pilot technique: speeds, configuration and timing make a big difference in short-field performance.(Airplane Flying Handbook (FAA-H-8083-3C))
  • Loading: weight increases takeoff distance and stall speed; CG location changes stability and control.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)
  • Expect actual performance to be worse than the book: a worn engine, a dirty airplane, soft ground. Add a margin and set an abort point.(Airplane Flying Handbook (FAA-H-8083-3C))
Aerodynamics
  • A wing stalls at its critical angle of attack, at any airspeed or attitude. Load factor raises the speed at which it happens.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aerodynamics of Flight)
  • Turns, pull-ups and turbulence increase load factor. Limit load factors, flaps up: normal category +3.8 and -1.52 G; utility +4.4 and -1.76 G; acrobatic +6.0 and -3.0 G. With flaps extended the limits are lower.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aerodynamics of Flight)
  • VA = stall speed × √(limit load factor), so it falls when weight lowers the stall speed. In turbulence, fly at or below the POH turbulence-penetration speed (often near VA for your weight).(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aerodynamics of Flight)
Limitations
  • The POH/AFM Limitations section (speeds, weights, CG range, load factors, kinds of operation) is the law for that airplane.(14 CFR 91.9)
  • Weight and balance: weight × arm = moment for each item; CG = total moment ÷ total weight. Check it on the envelope for takeoff and for landing (or zero fuel), since burning fuel moves the CG.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Weight and Balance; Aircraft Weight and Balance Handbook (FAA-H-8083-1))
  • Bags and passengers move the CG. Compute weight and balance for every flight with real weights.(Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Aircraft Performance)

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

3 · Say it out loud

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

  1. Remember Recall it

    “What three things increase density altitude?”

  2. Understand Explain why

    “Why is maneuvering speed lower at a lighter weight?”

  3. Apply Use it on a flight

    “Hot afternoon, a 2,800-foot runway, and with four passengers the book takeoff distance over 50 feet is 2,300 feet. What do you do?”

4 · Common mistakes

  • Using book numbers without margin.

    Real airplanes and pilots do worse.

    Instead: Add a margin and set an abort point.

  • Guessing passenger and bag weights.

    The CG can end up out of limits.

    Instead: Ask or weigh, and compute.

  • Treating weight and CG as one limit.

    Under gross can still be out of CG.

    Instead: Check both every time.

5 · Quick check

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

  1. 1. What does high density altitude do to takeoff?

  2. 2. Load factor in a 60° banked level turn?

  3. 3. How does maneuvering speed change as weight decreases?

  4. 4. What does an aft CG do?

  5. 5. Why add a margin to book performance?

  6. Scenario6. A customer wants to bring golf bags, which puts you 30 pounds over gross. What do you do?

Trained it? Now prove it: practice performance and limitations (commercial) 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 Preparation

A week after your checkride, a friend's company offers to pay you to fly three employees to a meeting in a rented 172. They want to leave at 6 a.m.; you have a full workday before.

Can you take the job, and what else matters? Decide, then see the worked answer

It turns on who provides the airplane and who has operational control. If you rent the 172 and provide the company pilot plus airplane, that's carrying persons for compensation, and offering it (holding out, under AC 120-12A) makes it common carriage. That needs an operator certificate under Part 119, with the flight run as an on-demand Part 135 operation, so decline. The lawful version is the company renting or leasing the airplane in its own name, holding operational control, and paying you only to fly it. That's a Part 91 flight, and your commercial certificate lets you be paid as its pilot (the FAA's Green (1993) and Ferris (1990) interpretations draw this line). None of the 119.1(e) exceptions, such as student instruction, nonstop commercial air tours under 91.147, ferry or training flights, or aerial work like banner towing, covers flying a company's employees to a meeting. 91.409(b) requires a 100-hour inspection for an aircraft carrying any person, other than a crewmember, for hire, or used for flight instruction for hire in an airplane the instructor provides. Company employees flown on the company's own business, without being charged, aren't passengers for hire in that sense, so it doesn't automatically apply to the Part 91 version; check the airplane's inspections either way. Then check yourself: a second-class medical for commercial privileges, a current flight review, and three takeoffs and landings in the last 90 days to carry passengers. Without an instrument rating, 61.133(b)(1) bars carrying passengers for hire on cross-countries over 50 NM or at night. Part 91 has no duty or rest limits, so fatigue is yours to manage: run IMSAFE honestly, and a 6 a.m. report after a full workday needs a real sleep opportunity first. If you won't get one, decline or move the departure. Pressure to please a client makes the call harder, not different.

14 CFR 61.23, 61.56, 61.57, 61.133, 91.409(b), 119.1; AC 120-12A; Risk Management Handbook (FAA-H-8083-2A)

Brings together: Pilot Qualifications · Airworthiness Requirements · Human Factors

Teaching this? The instructor lesson plan →

Study aid, not FAA guidance. Sources: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C); Airplane Flying Handbook (FAA-H-8083-3C); 14 CFR; Commercial Pilot ACS (FAA-S-ACS-7B). Checked against current sources 2026-11-13.