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Meaning of phantom lines

Aviation Mechanic General (AMG) practice question 7 of 15 on Aircraft Drawings. ACS element AM.I.B.K1 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic General (AMG) practice mode.

Question bank updated 2026-09-22

QUESTIONWhat does a phantom line on an aircraft drawing indicate?

  1. AAn alternate position of a part or a missing part
  2. BInvisible edges or contours behind a visible surface
  3. CThe plane at which a sectional view of the object is taken
Show the answer and explanation

Correct answer: A. An alternate position of a part or a missing part

  • A — correct Phantom lines indicate the alternate position of parts of the object or the relative position of a missing part; they are drawn as one long and two short evenly spaced dashes.
  • B — incorrect Invisible edges or contours are shown by hidden lines, which consist of short evenly spaced dashes.
  • C — incorrect The plane where a sectional view is taken is shown by a cutting plane line, not a phantom line.

BACKGROUND

Aircraft drawings use several standardized dashed lines, each with its own meaning. A phantom line is composed of one long and two short evenly spaced dashes. It shows either the alternate position of a part of the object (for example, a lever in a second position) or the relative position of a part that is not drawn. Hidden lines show invisible edges, and cutting plane lines show where a section is taken, so the three should not be confused.

STUDY TIP

Associate the word phantom with something that is not really there in the view: an alternate position or a missing part.

KEY POINTS

  • Phantom lines are one long and two short evenly spaced dashes.
  • They show an alternate position of a part or the position of a missing part.
  • Hidden lines and cutting plane lines serve different purposes.

SOURCES

  • FAA-H-8083-30B ch04 "Phantom Lines"
  • FAA-H-8083-30B ch04 "Hidden Lines"
  • FAA-H-8083-30B ch04 "Cutting Plane and Viewing Plane Lines"
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MORE ON AIRCRAFT DRAWINGS

SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-30B Aviation Maintenance Technician Handbook – General, 14 CFR part 43 and part 65. Regulations and handbooks are revised; confirm details against the current edition.