This overview includes information to help you prepare for the Officer Aptitude Rating, or OAR, portion of the ASTB-E. You’ll find details about the test format, scoring, registration, retakes, study resources, and sample practice questions.
Test TypeMilitary officer aptitude assessment | OAR SectionsMath Skills, Reading Comprehension, and Mechanical Comprehension |
Score Range20 to 80 | CostNo testing fee |
Exam Background and Purpose
The Officer Aptitude Rating, or OAR, is part of the Aviation Selection Test Battery, also known as the ASTB-E. The ASTB-E is used by the U.S. Navy, Marine Corps, and Coast Guard to evaluate candidates for aviation officer programs, and portions of the test are also used by the Navy for selection into Officer Candidate School for various officer communities.
The OAR focuses on academic and mechanical aptitude. Some candidates only need the OAR portion, while aviation candidates may need to complete the full ASTB-E battery. Confirm your exact testing requirement with your recruiter, officer selection office, or program administrator before studying.
Key point: if you are applying to a non-aviation officer program, you may only need the OAR. If you are applying for a pilot, naval flight officer, or other aviation pathway, you may need the full ASTB-E.
OAR vs. Full ASTB-E
The OAR is not the same thing as the full ASTB-E. The OAR uses only the Math Skills Test, Reading Comprehension Test, and Mechanical Comprehension Test. The full ASTB-E includes additional aviation-related and performance-based measures for aviation applicants.
Test Overview
The OAR is computer-based and delivered through the APEX testing system. The Math Skills Test, Reading Comprehension Test, and Mechanical Comprehension Test are administered in a computer-adaptive format, meaning the questions you see can depend on how you answer earlier questions.
Because the OAR is adaptive, you should answer carefully and keep moving at a steady pace. On adaptive subtests, you cannot go back to previous questions, and randomly guessing near the end can hurt your score more than leaving a few questions unanswered after working diligently.
OAR Sample Practice Questions
Try these original OAR-style sample questions. These examples reflect the Math Skills, Reading Comprehension, and Mechanical Comprehension sections, but they are not actual ASTB-E or OAR exam questions.
1. Math Skills: Algebra
If 3/4x + 5 = 23, what is the value of x?
- 18
- 20
- 24
- 28
Show Answer and Explanation
Answer: C. 24
Subtract 5 from both sides to get 3/4x = 18. Multiply both sides by 4/3: x = 24.
2. Math Skills: Geometry
A right triangle has a hypotenuse of 13 inches and one leg of 5 inches. What is the length of the other leg?
- 8 inches
- 10 inches
- 12 inches
- 18 inches
Show Answer and Explanation
Answer: C. 12 inches
Use the Pythagorean theorem: 5² + b² = 13². So 25 + b² = 169, and b² = 144. Therefore, b = 12.
3. Math Skills: Probability
A bag contains 3 red marbles and 2 blue marbles. If two marbles are drawn without replacement, what is the probability that both marbles are red?
- 1/5
- 3/10
- 2/5
- 3/5
Show Answer and Explanation
Answer: B. 3/10
The probability of drawing a red marble first is 3/5. After one red marble is removed, the probability of drawing another red marble is 2/4. Multiply: 3/5 × 2/4 = 6/20 = 3/10.
4. Reading Comprehension: Inference from the Passage
A maintenance log is most useful when it records both completed repairs and observed conditions that do not yet require repair. A minor vibration, for example, may not justify removing equipment from service, but documenting the vibration allows technicians to determine whether the condition changes over time.
Which statement can be inferred from the passage itself?
- Equipment should be removed from service whenever a vibration is observed.
- Maintenance logs should include only repairs that have already been completed.
- Documenting minor conditions can help technicians identify changes over time.
- Technicians should ignore observed conditions that do not require immediate repair.
Show Answer and Explanation
Answer: C. Documenting minor conditions can help technicians identify changes over time.
The passage states that documenting a minor vibration allows technicians to determine whether the condition changes over time. Choice C is the only option derived directly from the passage.
5. Reading Comprehension: Logical Conclusion
A unit policy states that equipment issued for training must be inspected before use and returned to storage immediately after training unless a supervisor authorizes continued use. Equipment found to be damaged must be tagged and reported before it is stored.
Which action is supported by the policy?
- Damaged equipment should be returned to storage without being reported.
- Equipment may remain in use after training only if a supervisor authorizes it.
- Inspection is required only after equipment is returned to storage.
- All equipment must be discarded after training.
Show Answer and Explanation
Answer: B. Equipment may remain in use after training only if a supervisor authorizes it.
The policy says equipment must be returned immediately after training unless a supervisor authorizes continued use. Choice B follows directly from that rule.
6. Mechanical Comprehension: Levers
A lever is balanced on a fulcrum. A 150-pound load is 2 feet from the fulcrum. How much force must be applied 6 feet from the fulcrum on the opposite side to balance the lever?
- 25 pounds
- 50 pounds
- 75 pounds
- 150 pounds
Show Answer and Explanation
Answer: B. 50 pounds
Balance the torque on each side: 150 × 2 = F × 6. So 300 = 6F, and F = 50 pounds.
7. Mechanical Comprehension: Gears
Gear A turns clockwise and meshes with Gear B. Gear B meshes with Gear C. If all three gears are arranged in a row, which direction does Gear C turn?
- Clockwise
- Counterclockwise
- It does not turn
- The direction cannot be determined unless the gear sizes are known
Show Answer and Explanation
Answer: A. Clockwise
Meshed gears rotate in opposite directions. Gear A turns clockwise, so Gear B turns counterclockwise. Gear C meshes with Gear B, so Gear C turns clockwise.
8. Mechanical Comprehension: Pressure and Fluids
A hydraulic lift has a small piston with an area of 2 square inches and a large piston with an area of 10 square inches. If 20 pounds of force is applied to the small piston, what force is produced by the large piston, assuming no losses?
- 40 pounds
- 80 pounds
- 100 pounds
- 200 pounds
Show Answer and Explanation
Answer: C. 100 pounds
Pressure is force divided by area. The pressure on the small piston is 20 ÷ 2 = 10 pounds per square inch. That same pressure acts on the large piston: 10 × 10 = 100 pounds.
How Is the OAR Scored?
The OAR score is reported on a scale from 20 to 80 in one-point increments. Candidates who take only the OAR receive one score. Candidates who take the full ASTB-E may receive additional aviation-related scores, depending on the program.
There is no single universal OAR score requirement that applies to every officer program. Minimum requirements vary by service branch, program, and current selection needs, so candidates should ask their recruiter or program administrator what score is competitive for their pathway.
OAR Score Basics
- OAR score range: 20 to 80
- Score use: officer-program selection and academic-performance prediction
- Program requirements: vary by service branch and officer community
- Score timing: OAR scores are generated after completion in APEX
- Most recent score: the most recent ASTB-E/OAR attempt replaces previous scores as the score of record
Registration, Costs, and Testing Options
OAR and ASTB-E scheduling is usually handled through a recruiter, officer selection office, NROTC unit, Marine Corps Officer Selection Office, military institute, or other authorized testing location.
There is no cost to take the ASTB-E or OAR. Candidates should still confirm testing instructions, eligibility, location, required documents, and appointment details with the official testing contact before test day.
Before You Register
- Confirm whether you need the OAR only or the full ASTB-E.
- Ask your recruiter or program administrator which scores are required for your officer pathway.
- Schedule through an authorized testing location.
- Confirm the exact appointment time, location, and check-in instructions.
- Bring photo identification and any required verification documents.
- Do not bring prohibited electronics, calculators, watches with calculators, notes, or personal belongings into the testing room.
- Be prepared to complete math questions without a calculator.
Retaking the OAR or ASTB-E
Candidates are allowed no more than three attempts at the current version of the ASTB-E or OAR. After three attempts, the candidate is no longer eligible for ASTB testing.
A retest may be administered only after 30 full calendar days have elapsed between the completion date of the first full ASTB administration and the start date of the retest. Candidates who take the full ASTB-E and retest must retake the full battery; scores cannot be mixed and matched from separate attempts.
Retake Rules to Know
- Attempt limit: three attempts at ASTB-E/OAR Series E
- Waiting period: at least 30 full calendar days between qualifying administrations
- Score of record: the most recent test attempt replaces previous scores
- No score mixing: candidates retaking the full ASTB-E must retake the full battery
- Best approach: use the waiting period to fix weak areas before retesting
How Can I Prepare for the OAR?
Start by confirming whether your program requires only the OAR or the full ASTB-E. For OAR-only preparation, focus heavily on math speed and accuracy, passage-based reasoning, and practical mechanical principles.
Because the OAR is adaptive and does not allow you to revisit earlier questions, practice answering accurately on the first attempt. For reading, pay close attention to whether the answer can be proven from the passage itself. For math and mechanical comprehension, review the underlying rule behind every missed question.
OAR Study Checklist
- Review arithmetic, fractions, decimals, ratios, exponents, roots, and probability.
- Practice algebraic equations, word problems, geometry, area, perimeter, angles, and distance-rate-time problems.
- Practice dense reading passages where the correct answer must come only from the text.
- Review mechanical advantage, levers, pulleys, gears, wheels, fluids, pressure, electricity, motion, and energy.
- Practice mental math and written scratch-work because calculators are not allowed.
- Use timed practice sets to build pacing without rushing into random guesses.
- Review missed questions by identifying the exact math rule, reading clue, or mechanical principle you missed.
- Confirm program-specific score expectations with your recruiter before retesting.
OAR Study Resources
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ASTB-E, Aviation Selection Test Battery, OAR, and Officer Aptitude Rating are terms associated with military officer selection testing. StudyGuideZone and Mometrix are not affiliated with or endorsed by the U.S. Navy, U.S. Marine Corps, U.S. Coast Guard, Department of Defense, or any official military testing authority.
