Airframe Mechanic Certification Cheat Sheet 2026

The 30 highest-yield Airframe Mechanic Certification facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. During an inspection of a control cable passing over a pulley, a single broken wire is discovered. According to FAA AC 43.13-1B, what action is required? → The entire control cable assembly must be replaced.
2. What color dye is used to identify 100LL aviation gasoline (avgas)? → Blue
3. What is the role of the empennage in an aircraft? → It provides stability and control during flight.
4. Which of the following describes the minimum allowable edge distance for a single row of protruding head rivets in a sheet metal repair? → Two times the rivet shank diameter
5. In aircraft assembly and maintenance, what is the primary function of a cotter pin when used with a castellated nut? → To act as a positive locking device to prevent the nut from loosening due to vibration.
6. What is the primary function of a centering cam in a retractable nose landing gear system? → To align the nose wheel in the fore-and-aft direction before retraction.
7. What type of material is often used in aircraft for areas requiring high strength-to-weight ratio? → Composites like carbon fiber are used for their strength-to-weight ratio.
8. What should be done if a safety protocol is violated by an aircraft crew member? → It should be reported, and corrective action should be taken
9. What fuel selector valve position is recommended during takeoff and landing on most aircraft with multiple fuel tanks? → Both tanks or the fullest tank
10. An aircraft's pneumatic system, often powered by engine bleed air, is commonly used to operate which of the following systems? → Cabin pressurization, air conditioning, and anti-icing systems.
11. What should be done if a safety hazard is identified during aircraft maintenance? → Report the hazard and take corrective actions
12. Why is proper aircraft system maintenance important? → To ensure systems operate safely and effectively
13. In a pneumatic system, what is the primary function of a moisture separator or water trap? → To remove water vapor and contaminants from the compressed air.
14. A twisting force is applied to an aircraft engine mount during operation. What is the primary type of stress this component must resist? → Torsion
15. Which of the following is a key component of safety procedures? → Emergency response and evacuation procedures
16. Which of the following is considered a major repair to an airframe sheet metal structure according to 14 CFR Part 43, Appendix A? → The repair of damaged areas in stressed covering exceeding six inches in any direction.
17. What is the primary function of a static inverter in an aircraft electrical system? → To convert DC power from the aircraft battery or DC bus to AC power.
18. In a typical aircraft hydraulic system, what is the primary function of a hydraulic accumulator? → To store hydraulic fluid under pressure for normal and emergency use.
19. In a pneumatic system, what is the primary purpose of a moisture separator or chemical dryer component? → To remove water vapor and prevent corrosion or freezing.
20. What regulation governs fuel system airworthiness design requirements for certificated aircraft? → 14 CFR Part 23 or Part 25, depending on aircraft category
21. What is the function of a fuel strainer (gascolator) installed in an aircraft fuel system? → To remove water and debris from fuel before it reaches the engine
22. After a minor repair and repainting of an aileron, what procedure is critical to perform to prevent a potentially catastrophic in-flight failure? → Re-balancing the control surface.
23. In the context of an aircraft sheet metal repair, what is the primary function of a joggle? → To allow one sheet of metal to overlap another while maintaining a flush surface.
24. How are aircraft structures designed to withstand pressurization? → With reinforced skin and frames to handle internal pressure.
25. What is the primary purpose of the fuselage in an aircraft? → To carry the aircraft’s passengers, crew, and cargo
26. Which of the following are all considered primary flight controls? → Ailerons, elevator, and rudder.
27. When an inspector performs a 'tap test' on a bonded honeycomb composite panel, what is the primary type of defect they are trying to detect? → Delamination or disbond between the face sheet and core
28. Which type of hydraulic fluid is known for its fire-resistant properties and is commonly used in modern commercial transport aircraft? → Phosphate ester-based fluid (e.g., Skydrol)
29. What is the primary purpose of a fuel boost pump in an aircraft fuel system? → To provide positive fuel pressure and prevent vapor lock
30. What is the function of the engine fire detection system? → To detect and alert about engine fires