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Category eligibility from kinetic energy

Remote Pilot (Part 107) practice question 1 of 19 on Operations / Emergency Procedures. ACS element UA.V.C.K6 · difficulty: applied. Want to answer it in a timed quiz? Use the Remote Pilot (Part 107) practice mode.

Question bank updated 2026-09-22

QUESTIONTesting shows that a small unmanned aircraft would cause an injury equivalent to a transfer of 18 foot-pounds of kinetic energy from a rigid object on impact. It has no exposed rotating parts that would lacerate skin and no safety defects. Under §§ 107.120 and 107.130, for which operational category over people is the aircraft eligible?

  1. ACategory 2
  2. BCategory 4, without an airworthiness certificate
  3. CCategory 3
Show the answer and explanation

Correct answer: C. Category 3

  • A — incorrect Category 2 eligibility under § 107.120(a)(1) requires an injury less than that from 11 foot-pounds of kinetic energy; 18 foot-pounds exceeds that limit.
  • B — incorrect Category 4 eligibility under § 107.140(b)(1) requires an airworthiness certificate issued under part 21; kinetic energy testing does not qualify an aircraft for Category 4.
  • C — correct Category 3 eligibility under § 107.130(a)(1) requires an injury less than that from 25 foot-pounds; 18 foot-pounds meets that threshold but exceeds the 11 foot-pound limit for Category 2.

BACKGROUND

Subpart D of part 107 defines four categories of operations over people. Category 2 and Category 3 eligibility both depend on the injury the aircraft could cause. Under § 107.120(a)(1), a Category 2 aircraft must not cause an injury equivalent to or greater than that from a transfer of 11 foot-pounds of kinetic energy 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 skin and no safety defects. An aircraft at 18 foot-pounds is above the Category 2 limit but below the Category 3 limit, so it can be eligible only for Category 3. Category 4 depends instead on an airworthiness certificate under part 21.

STUDY TIP

Memorize the two kinetic energy thresholds, 11 foot-pounds for Category 2 and 25 foot-pounds for Category 3, and place any test value between them.

KEY POINTS

  • Category 2 requires injury below the 11 foot-pound kinetic energy equivalent.
  • Category 3 requires injury below the 25 foot-pound kinetic energy equivalent.
  • A value between 11 and 25 foot-pounds qualifies only for Category 3.

SOURCES

  • 14 CFR 107.120(a)(1)
  • 14 CFR 107.130(a)(1)
  • 14 CFR 107.140(b)(1)
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MORE ON OPERATIONS / EMERGENCY PROCEDURES

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.