SkyDrill

Wire count of a 7 × 19 control cable

Aviation Mechanic Airframe (AMA) practice question 7 of 16 on Flight Controls. ACS element AM.II.C.K1 · difficulty: applied. Want to answer it in a timed quiz? Use the Aviation Mechanic Airframe (AMA) practice mode.

Question bank updated 2026-09-22

QUESTIONAn aircraft control cable carries the designation 7 × 19. How many individual wires does the complete cable contain?

  1. A133 wires
  2. B49 wires
  3. C19 wires per cable
Show the answer and explanation

Correct answer: A. 133 wires

  • A — correct A 7 × 19 cable is made up of seven strands of 19 wires each, so 7 × 19 = 133 individual wires.
  • B — incorrect Forty-nine wires is the count for a 7 × 7 cable, which has seven strands of seven wires each.
  • C — incorrect Nineteen is the number of wires in one strand, not the number of wires in the whole cable.

BACKGROUND

Aircraft control cable designations are based on the number of strands in the cable and the number of wires in each strand. The basic component of a cable is a wire; a number of wires are preformed into a helical shape and formed into a strand, and the strands are laid around a straight center strand to form the cable. A 7 × 19 cable has seven strands of 19 wires each, with six strands laid around the center strand; it is very flexible and is used in primary control systems and wherever operation over pulleys is frequent. A 7 × 7 cable has seven strands of seven wires each, is of medium flexibility, and is used for trim tab controls, engine controls, and indicator controls. Multiplying the two numbers in the designation gives the total wire count.

STUDY TIP

Read a cable designation as strands times wires per strand, and remember which construction goes with primary controls and which with trim and engine controls.

KEY POINTS

  • The first number in a cable designation is strands, the second is wires per strand.
  • 7 × 19 = 133 wires; it is the flexible cable used in primary control systems.
  • 7 × 7 = 49 wires; medium flexibility, used for trim tab, engine, and indicator controls.

SOURCES

  • sources/ama-airframe/ch02.txt "Control Operating Systems — Cable Systems"
Practice the Aviation Mechanic Airframe (AMA) test →Timed 100-question exam, by ACS area, or review your misses. Free.
MORE ON FLIGHT CONTROLS

SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-31B Aviation Maintenance Technician Handbook – Airframe, and 14 CFR part 43. Regulations and handbooks are revised; confirm details against the current edition.