Does load factor increase stalling speed in direct proportion?

No — stalling speed increases with the square root of load factor. A 50-knot aircraft under a 2.000 G load factor (a 60° bank) stalls around 50 × √2.000 ≈ 71 knots, not 100 knots (remote_pilot_study_guide.pdf, p. 32; sport_rec_private_akts.pdf, Figure 2, p. 2-2).

Can a small UA actually reach a 90° banked, constant-altitude turn?

No. Load factor rises toward infinity as bank angle approaches 90°, so a 90° banked turn at constant altitude is not mathematically possible (remote_pilot_study_guide.pdf, p. 32).

What's the first step in using the density altitude chart?

Convert field elevation to pressure altitude using the chart's altimeter-setting conversion table (pressure altitude = field elevation + conversion factor), then combine that pressure altitude with outside air temperature on the main graph (sport_rec_private_akts.pdf, Figure 8, p. 2-8).

What preflight battery findings indicate a possible impending failure?

A distorted or bulging battery casing, and diminishing flight time capability on an electric-powered aircraft — both can signal a battery no longer reliable as a power source, with a risk of fire or extreme heat (AC_107-2A.pdf, Table C-1, p. C-3).

Part 107 Loading & Performance Guide

The complete FAA Part 107 loading and performance guide: weight, CG, load factor, the density altitude chart, battery behavior — with worked arithmetic.

Loading and Performance is 2% of the current FAA Part 107 knowledge test — the smallest-weighted area overall — and maps to ACS Area of Operation IV, Task A (uas_acs.pdf, p. 13). It’s a small slice of the test, but it’s the area where a bad call has the most direct physical consequences: an overloaded or out-of-CG aircraft can fail to fly the way its manufacturer’s data says it should.

Weight, balance, and center of gravity

Before every flight, a remote pilot in command must verify the aircraft is correctly loaded by determining its weight and balance condition, following the manufacturer’s (or builder’s) limits (remote_pilot_study_guide.pdf, p. 29). Two separate things can go wrong:

Too much weight. A maximum gross takeoff weight doesn’t mean the aircraft can safely take off at that weight under every condition — high elevation, high temperature, high humidity (all of which raise density altitude), plus runway/launch-area length, surface, slope, wind, and nearby obstacles can all force a weight reduction before flight (remote_pilot_study_guide.pdf, p. 29).
Weight in the wrong place. The center of gravity (CG) is the point where the aircraft’s weight is effectively concentrated, and it isn’t a fixed marked point — it shifts as load items are added, shifted, or expended in flight (such as a jettisonable payload). If the CG isn’t within the manufacturer’s allowable limits after loading, or won’t stay within them through the flight, weight has to be relocated or shed before flight (remote_pilot_study_guide.pdf, p. 29). CG position also drives pitch tendency: CG forward of the center of pressure (CP) creates a nose-down tendency, and CP forward of CG creates a nose-up tendency, which is why designers fix the CG’s aft limit forward of the CP (remote_pilot_study_guide.pdf, p. 29).

Stability — the aircraft’s inherent tendency to correct for disturbances and return to its original flight path — is a design characteristic that governs both maneuverability (how easily the aircraft can be maneuvered and withstand the resulting stresses) and controllability (how well it responds to the pilot’s control inputs) (remote_pilot_study_guide.pdf, p. 30).

Effects of excess weight

Adding weight to an aircraft forces a higher angle of attack to hold altitude and speed, which increases both induced and parasite drag — leaving less reserve thrust for climbing (remote_pilot_study_guide.pdf, p. 30). An overloaded aircraft typically shows every one of these at once: higher takeoff speed, longer takeoff run, reduced rate and angle of climb, lower maximum altitude, shorter range, reduced cruising speed, reduced maneuverability, higher stalling speed, higher approach/landing speed, and a longer landing roll (remote_pilot_study_guide.pdf, p. 33). That shorter-range effect is the core of the payload/endurance trade-off: a manufacturer’s performance data typically specifies range and endurance limitations alongside the power source’s endurance, power setting, and consumption levels — numbers that degrade together as payload weight goes up (AC_107-2A.pdf, para. 8.12.2.5.1, p. 8-35).

Load factor

Load factor is the ratio between the total load on the aircraft’s structure and its weight, measured in Gs — a load factor of 3 means the structure is carrying three times the aircraft’s weight (remote_pilot_study_guide.pdf, p. 30). In a coordinated, level turn, load factor comes from the combination of centrifugal force and weight, and it climbs steeply once bank angle passes about 45–50° (remote_pilot_study_guide.pdf, pp. 31–32). Figure 2’s table gives exact values:

Bank angle	Load factor
60°	2.000 G
70°	2.923 G
80°	5.747 G

(sport_rec_private_akts.pdf, Figure 2, p. 2-2.)

A 90°-banked, constant-altitude turn is never reached — it isn’t mathematically possible — but slightly past 80°, load factor already exceeds 6 Gs, the limit load factor of an acrobatic aircraft (remote_pilot_study_guide.pdf, p. 32).

Load factor matters because stalling speed increases with the square root of load factor, not load factor itself. Worked example: a small UA with a 50-knot unaccelerated stalling speed, turning at a coordinated 60° bank (2.000 G from the table above), stalls at approximately 50 kt. × √2.000 ≈ 50 × 1.414 ≈ 71 knots — not 100 knots, which would wrongly assume a linear relationship (remote_pilot_study_guide.pdf, p. 32).

Density altitude and the performance chart

Density altitude chart for converting pressure altitude and outside air temperature to approximate density altitude, with an altimeter-setting conversion table. — Figure 8 — Density Altitude Chart · FAA-CT-8080-2H, p. 2-8

As the Weather guide covers, density altitude — not field elevation — is what actually governs performance: high density altitude (thin air) degrades it, low density altitude (dense air) improves it. Figure 8 converts field elevation and the current altimeter setting into pressure altitude using a conversion-factor table, which is the starting point for reading density altitude off the chart’s main graph (remote_pilot_study_guide.pdf, p. 21; sport_rec_private_akts.pdf, Figure 8, p. 2-8).

Two worked examples, both using pressure altitude = field elevation + conversion factor:

Field elevation 1,000 ft., altimeter 30.1” Hg. The table’s conversion factor at 30.1” Hg is −165. Pressure altitude = 1,000 + (−165) = 835 ft.
Field elevation 3,000 ft., altimeter 28.5” Hg. The table’s conversion factor at 28.5” Hg is +1,340. Pressure altitude = 3,000 + 1,340 = 4,340 ft.

(sport_rec_private_akts.pdf, Figure 8, p. 2-8.) The sign flips on either side of the standard setting, 29.92” Hg — a setting below standard adds a positive correction, a setting above it subtracts. Once pressure altitude is known, the remote pilot combines it with outside air temperature on Figure 8’s main graph to read density altitude, and uses that to judge whether the day’s conditions call for a reduced takeoff weight (sport_rec_private_akts.pdf, Figure 8, p. 2-8).

Battery behavior

Most small UAS are electric, and lithium-based batteries are highly flammable and capable of ignition from a short circuit, improper charging, extreme heat, crash damage, mishandling, or a simple defect — a battery fire in flight is itself an emergency, and 14 CFR part 107 lets a remote PIC deviate from any rule to respond to one (AC_107-2A.pdf, para. B.5, p. B-3; remote_pilot_study_guide.pdf, p. 35). Two preflight-inspection findings the FAA specifically flags as impending-failure warning signs:

A distorted (bulging) battery casing — may mean the battery can no longer be trusted as a reliable power source, with a risk of abrupt power loss, fire, or explosion.
Diminishing flight time capability on an electric-powered aircraft — may signal exhausted service life or internal/external damage, again with a risk of fire or extreme heat affecting both structure and flight duration.

Either finding means further inspection before flight, and assessing what repairs are needed for safe continued operation (AC_107-2A.pdf, Table C-1, p. C-3).

Drill this guide’s material with Loading & Performance practice questions, print the numbers to memorize cheat sheet, see how density altitude is defined and measured in the Weather guide, or check the exam’s full topic breakdown at What’s Actually on the Part 107 Test.

Frequently asked questions

Does load factor increase stalling speed in direct proportion?: No — stalling speed increases with the square root of load factor. A 50-knot aircraft under a 2.000 G load factor (a 60° bank) stalls around 50 × √2.000 ≈ 71 knots, not 100 knots (remote_pilot_study_guide.pdf, p. 32; sport_rec_private_akts.pdf, Figure 2, p. 2-2).; Drill loading & performance questions →
Can a small UA actually reach a 90° banked, constant-altitude turn?: No. Load factor rises toward infinity as bank angle approaches 90°, so a 90° banked turn at constant altitude is not mathematically possible (remote_pilot_study_guide.pdf, p. 32).; Review the numbers to memorize →
What's the first step in using the density altitude chart?: Convert field elevation to pressure altitude using the chart's altimeter-setting conversion table (pressure altitude = field elevation + conversion factor), then combine that pressure altitude with outside air temperature on the main graph (sport_rec_private_akts.pdf, Figure 8, p. 2-8).; Read the Weather guide →
What preflight battery findings indicate a possible impending failure?: A distorted or bulging battery casing, and diminishing flight time capability on an electric-powered aircraft — both can signal a battery no longer reliable as a power source, with a risk of fire or extreme heat (AC_107-2A.pdf, Table C-1, p. C-3).; Drill loading & performance questions →