See What the Test Looks Like
Here are sample questions from our SIFT Mechanical Comprehension practice tests. Each question comes with a detailed explanation so you understand the reasoning, not just the answer.
Variable questions, ~15 minutes. Adaptive test on mechanics, physics, and machines — master mechanical principles for Army aviation.
Mechanical Comprehension is the second adaptive subtest on the SIFT. It tests your understanding of basic mechanical and physical principles: how gears, pulleys, and levers work, fluid dynamics, basic thermodynamics, and general physics. Questions often include diagrams of mechanical systems. Like Math Skills, it adapts to your level — get answers right and the questions get harder.
Mechanical Comprehension (MCT) tests your understanding of mechanical and physical principles. Like Math Skills, it's a Computer Adaptive Test (CAT) that adjusts difficulty based on your performance. Answer correctly and questions get harder; answer incorrectly and they get easier.
The test covers simple machines (levers, pulleys, gears), force and motion (Newton's laws, gravity, friction), fluid dynamics (pressure, hydraulics, Bernoulli's principle), and basic electricity and thermodynamics. Many questions include diagrams showing mechanical systems — gear trains, pulley setups, lever configurations, or hydraulic circuits.
Because it's adaptive, the number of questions varies — typically 15–25 questions in approximately 15 minutes. Early questions establish your baseline difficulty level, so they have outsized influence on your score. Strong performers will see advanced physics questions; those struggling will see more basic mechanical concepts.
Mechanical Comprehension is one of seven subtests that collectively produce your SIFT score (scored 20–80). The SIFT is a computerized test required for all U.S. Army aviation candidates.
Here are sample questions from our SIFT Mechanical Comprehension practice tests. Each question comes with a detailed explanation so you understand the reasoning, not just the answer.
| Questions | Variable (CAT — Computer Adaptive Testing) |
| Time Limit | Approximately 15 minutes |
| Time per Question | Varies — the test adapts |
| Format | Computer-based, multiple choice |
| Scoring | Based on difficulty level sustained |
| Adaptive? | YES — the difficulty adapts to your performance |
Key detail: Mechanical Comprehension is adaptive (CAT). You cannot skip questions or go back. Each correct answer raises difficulty; each wrong answer lowers it. Your score reflects the difficulty level you sustained, not just the number correct.
Mechanical Comprehension assesses understanding of mechanical and physical principles essential for aviation systems.
Levers, pulleys, gears, inclined planes, wedges, and screws. Understand mechanical advantage, force multiplication, and how these machines change the direction or magnitude of force.
Newton's laws, gravity, friction, acceleration, momentum, and work/energy concepts. These are the physics fundamentals behind how aircraft (and all machines) operate.
Pressure, hydraulics, pneumatics, Bernoulli's principle, and fluid behavior. Directly relevant to helicopter hydraulic systems, fuel systems, and aerodynamics.
Simple circuits (series vs. parallel), voltage/current/resistance, heat transfer, and basic thermodynamic concepts. Army aircraft rely on complex electrical and thermal systems.
Mechanical comprehension tests conceptual understanding. If you understand WHY a lever provides mechanical advantage, you can answer any lever question. Memorizing specific answers won't help on an adaptive test.
Many questions include mechanical diagrams. Practice interpreting gear trains, pulley systems, lever setups, and hydraulic circuits from diagrams. Be comfortable extracting information visually.
Gears, levers, and pulleys appear most frequently. For gears: meshing gears turn opposite directions, larger gears turn slower but with more torque. For levers: know the three classes. For pulleys: count the ropes supporting the load.
Newton's three laws, work = force × distance, pressure = force / area, and conservation of energy cover most of the physics on this test. These principles apply to nearly every question.
Many questions can be answered by thinking about real-world experience: which way does a door swing, what happens when you step on a garden hose, how does a seesaw balance? Trust your physical intuition and then verify with principles.
Mechanical Comprehension (MCT) is a computer-adaptive test covering mechanics, physics, and mechanical principles. It adapts to your performance level. Topics include simple machines, force and motion, fluids, and basic electricity. Total time is approximately 15 minutes.
The concepts overlap significantly, but the SIFT version is computer-adaptive (CAT), meaning difficulty adjusts based on your answers. The SIFT may also include more advanced questions if you perform well, testing deeper physics and mechanical reasoning.
No. The test starts at basic levels and only moves to advanced material if you're performing well. A solid understanding of high-school physics — Newton's laws, simple machines, pressure, and basic electricity — is sufficient for most candidates.
SIFT-specific prep books, the ASVAB Mechanical Comprehension study material (concepts overlap), and basic physics textbooks. Online physics simulations and mechanical reasoning practice tests are also highly effective.
Build your mechanical reasoning skills with SIFT practice tests and study resources.