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Aircraft systems and instrumentsQuestion 593 of 934

The air filter of the induction system is clogged. What is the alternate air source?

  1. Air from the cabin heater shroud
  2. Air from around the exhaust manifold
  3. Air from inside the engine cowling
  4. Air taken from the oil breather line
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Correct answer: Air from inside the engine cowling

The alternate air usually comes from inside the engine cowling, where it bypasses a clogged air filter.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 7: Aircraft Systems — Induction Systems, page 167

Practice aircraft systems and instruments

Questions last reviewed: 18 October 2026