SkyDrill

Category eligibility from an impact kinetic energy result

Remote Pilot (Part 107) practice question 15 of 19 on Regulations / Operations Over People. ACS element UA.I.E.K17 · difficulty: applied. Want to answer it in a timed quiz? Use the Remote Pilot (Part 107) practice mode.

Question bank updated 2026-09-22

QUESTIONThrough an accepted means of compliance, a manufacturer shows that its small unmanned aircraft will not cause an injury more severe than that caused by a transfer of 20 foot-pounds of kinetic energy from a rigid object. The aircraft has no exposed rotating parts and no safety defects. For which category or categories may it be declared eligible?

  1. ACategory 2 and Category 3, because 20 foot-pounds is below the 25 foot-pound Category 3 limit
  2. BCategory 3 only, because 20 foot-pounds exceeds the 11 foot-pound Category 2 limit
  3. CCategory 2 only, because 20 foot-pounds is below the 25 foot-pound limit set for Category 2
Show the answer and explanation

Correct answer: B. Category 3 only, because 20 foot-pounds exceeds the 11 foot-pound Category 2 limit

  • A — incorrect Being under the Category 3 threshold does not satisfy Category 2, which requires the injury severity to stay below the 11 foot-pound equivalent.
  • B — correct § 107.120(a)(1) sets the Category 2 threshold at 11 foot-pounds and § 107.130(a)(1) sets the Category 3 threshold at 25 foot-pounds. An injury level equivalent to 20 foot-pounds is above 11 but below 25, so the aircraft qualifies for Category 3 only.
  • C — incorrect The 25 foot-pound threshold belongs to Category 3; the Category 2 threshold is 11 foot-pounds, which 20 foot-pounds exceeds.

BACKGROUND

Categories 2 and 3 are defined by injury severity rather than by weight. Under § 107.120(a)(1), a Category 2 aircraft must not cause an injury equivalent to or greater than the severity caused by a transfer of 11 foot-pounds of kinetic energy upon impact from a rigid object. Under § 107.130(a)(1), the Category 3 threshold is 25 foot-pounds. Both categories also require no exposed rotating parts that would lacerate human skin and no safety defects. An aircraft whose demonstrated injury level falls between the two thresholds can be declared for Category 3 but not Category 2, which is why Category 3 carries stricter operating limits such as the prohibition on open-air assemblies.

STUDY TIP

Anchor the two numbers, 11 foot-pounds for Category 2 and 25 foot-pounds for Category 3, and compare the scenario value to each threshold separately.

KEY POINTS

  • Category 2 eligibility requires injury severity below the 11 foot-pound kinetic energy equivalent.
  • Category 3 eligibility requires injury severity below the 25 foot-pound equivalent.
  • Both categories also require no lacerating exposed rotating parts and no safety defects.

SOURCES

  • 14 CFR 107.120(a)(1)
  • 14 CFR 107.130(a)(1)
Practice the Remote Pilot (Part 107) test →Timed 60-question exam, by ACS area, or review your misses. Free.
MORE ON REGULATIONS / OPERATIONS OVER PEOPLE

SkyDrill is not affiliated with the FAA. This is an original practice item based on 14 CFR part 107, 14 CFR part 89, and the FAA Remote Pilot – Small UAS Study Guide (FAA-G-8082-22). Regulations and handbooks are revised; confirm details against the current edition.