Load Factor (G-Force)

Load factor, commonly spoken of as G-force, is defined in the FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25) as the ratio of the load supported by the wings to the actual weight of the aircraft and its contents. In unaccelerated straight-and-level flight the wings support exactly the aircraft's weight, so the load factor is 1 G. Any time lift exceeds weight — because the flight path is curving — the load factor climbs above 1.

The clearest everyday example is the level turn. In a coordinated, altitude-holding turn, load factor depends only on bank angle, not on aircraft type or airspeed. At a 30-degree bank the load factor is about 1.15 G; at 45 degrees it is about 1.41 G; and at 60 degrees it is 2.0 G, meaning the wings must produce twice the aircraft's weight in lift and the occupants feel twice their body weight. The relationship is non-linear and steepens sharply beyond 60 degrees: at 75 degrees of bank the level-turn load factor is nearly 4 G, which is why steep turns past 60 degrees demand rapidly increasing back-pressure and power and leave little structural margin in a normal-category airplane.

Load factor is inseparable from stall speed. Because a wing reaches its critical angle of attack at a higher airspeed when it must support a greater load, stall speed increases in proportion to the square root of the load factor. At 2 G the stall speed rises by a factor of the square root of 2 — about 1.41 — so an airplane that stalls at 50 knots wings-level will stall near 70 knots in a 2 G, 60-degree-bank turn. This is the mechanism behind the accelerated stall, and it explains why abrupt maneuvering at low airspeed is dangerous even when the airspeed indicator still shows a comfortable margin above the placarded stall speed.

Maneuvering speed, VA, is the practical limit that ties these ideas together. VA is the maximum speed at which a pilot can apply full, abrupt deflection of a single flight control without exceeding the airframe's limit load factor, because below VA the wing will stall — shedding load — before the structure is overstressed. VA decreases with weight, so a lighter aircraft has a lower maneuvering speed. Above VA, full control deflection or a strong gust can impose loads beyond structural limits, which is why pilots slow to or below VA in turbulence.

Certification defines the limit load factors an airframe must withstand. Under 14 CFR Part 23 and the equivalent EASA CS-23, normal-category airplanes must withstand at least +3.8 G and −1.52 G; utility category at least +4.4 G and −1.76 G; and acrobatic category at least +6.0 G and −3.0 G. The limit load is the maximum expected in service, and the structure must also survive an ultimate load of 1.5 times the limit without failure, though permanent deformation may occur between the two. Human tolerance is a separate limit: without a G-suit and anti-G straining, most people experience grey-out and then loss of consciousness (G-LOC) somewhere around +4 to +6 G depending on onset rate and conditioning, so both the airframe and the pilot impose ceilings on sustained load.

For a flight school, load factor is where aerodynamics, structural limits, and airmanship intersect, and it recurs across the syllabus from steep turns and chandelles to turbulence penetration and upset recovery. Students consistently underestimate how quickly required load factor climbs past 60 degrees of bank, and they conflate the airspeed-indicator margin with a stall margin that does not exist under G. Teaching load factor well is what makes an examiner's steep-turn and accelerated-stall questions land, and it is the foundation for a student's respect for maneuvering speed in turbulence.

Operationally, the concept touches dispatch and fleet management as well as instruction. Utility- and acrobatic-category maneuvers are only permitted within specific weight and center-of-gravity envelopes, so a school offering spin or aerobatic training has to confirm the aircraft is loaded inside the category limits for the intended maneuver — a weight-and-balance question that is really a load-factor question in disguise. VA changing with weight is another item that examiners and safety programs expect crews to apply correctly, particularly on lightly-loaded training flights.

Aviatize's Training Management module ties maneuvers that involve elevated load factor — steep turns, accelerated stalls, and upset recovery — to the observable behaviors that show whether a student is managing G, airspeed, and stall margin correctly, rather than simply completing the maneuver. For schools with utility- or acrobatic-category aircraft, the platform helps ensure those lessons are scheduled only in aircraft approved for the maneuver, keeping the category and its load limits front of mind.

Because load factor within limits depends on how the aircraft is loaded, Aviatize's Digital Data & Records keeps weight-and-balance data and aircraft limitations alongside the training record, so the loading assumptions behind a given lesson are documented and auditable rather than left to memory.