CAT Aircraft Systems and Components 1 — Questions and Answers
Question 1: What is the primary function of an aircraft's hydraulic system in large commercial aircraft?
- To actuate flight controls, landing gear, and brakes (Correct answer)
- To supply fuel to the engines
- To pressurize the cabin
- To generate electrical power
Correct answer: To actuate flight controls, landing gear, and brakes
Aircraft hydraulic systems use fluid under pressure to actuate primary and secondary flight controls, extend/retract landing gear, and apply brakes.
Question 2: Which type of aircraft structure uses the outer skin to carry primary structural loads?
- Monocoque (Correct answer)
- Truss
- Semi-monocoque
- Geodesic
Correct answer: Monocoque
A monocoque structure relies entirely on the outer skin to carry all structural loads, with no internal framework sharing the load.
Question 3: What does the term 'V-speeds' refer to in aviation?
- Defined airspeeds critical to aircraft operation and safety (Correct answer)
- Variable engine thrust settings
- Vertical climb rate benchmarks
- Vectored thrust velocity limits
Correct answer: Defined airspeeds critical to aircraft operation and safety
V-speeds are defined reference airspeeds (such as Vne, Vlo, Vs) that are critical to safe aircraft operations and are established during aircraft certification.
Question 4: In a turbofan engine, what is the purpose of the bypass ratio?
- It describes the ratio of air bypassing the engine core to air flowing through the core (Correct answer)
- It measures fuel-to-air mixture
- It indicates the ratio of turbine stages to compressor stages
- It defines the thrust reverser efficiency
Correct answer: It describes the ratio of air bypassing the engine core to air flowing through the core
Bypass ratio is the ratio of mass airflow bypassing the engine core to airflow through the core, with higher ratios indicating more fuel-efficient high-bypass turbofan engines.
Question 5: What is the function of an aircraft's pitot-static system?
- To measure airspeed, altitude, and vertical speed by sensing air pressure (Correct answer)
- To control cabin pressurization
- To direct boundary layer airflow over the wing
- To cool avionics equipment
Correct answer: To measure airspeed, altitude, and vertical speed by sensing air pressure
The pitot-static system uses pitot (dynamic) and static air pressure measurements to drive the airspeed indicator, altimeter, and vertical speed indicator.
Question 6: What type of corrosion is most common where two different metals are in contact in a moist environment?
- Galvanic corrosion (Correct answer)
- Uniform corrosion
- Crevice corrosion
- Intergranular corrosion
Correct answer: Galvanic corrosion
Galvanic corrosion occurs when two dissimilar metals are in electrical contact in a conductive electrolyte, causing the less noble metal to corrode preferentially.
CAT Aircraft Systems and Components 1
What is the primary function of an aircraft's hydraulic system in large commercial aircraft?