IA Engine & Powerplant Inspection Procedures 2 — Questions and Answers
Question 1: During an annual inspection, the IA checks the magneto-to-engine timing. What is the risk of advanced timing?
- Reduced fuel consumption and over-temperature risk
- Preignition and detonation that can damage pistons and cylinders (Correct answer)
- Retarded power output and rough running only
- Fouled spark plugs from incomplete combustion
Correct answer: Preignition and detonation that can damage pistons and cylinders
Timing that is too far advanced causes the fuel-air charge to ignite before the piston reaches the correct position, leading to preignition and potentially destructive detonation.
Question 2: What is the purpose of inspecting engine baffling and cooling fins during an annual?
- To ensure proper airflow directs cooling air over the cylinders and prevents overheating (Correct answer)
- To verify that the engine cowling paint is intact
- To confirm the oil cooler bypass valve is operating
- To measure cylinder fin corrosion for logbook entry
Correct answer: To ensure proper airflow directs cooling air over the cylinders and prevents overheating
Baffles direct cooling airflow over the cylinders; damaged or missing baffles cause hot spots and can lead to accelerated engine wear or failure.
Question 3: When should an IA inspect the engine fuel system for leaks during an annual?
- Only after the engine is started and warmed up
- With fuel on and the system pressurized, and again after run-up (Correct answer)
- Only at idle power with the engine running
- Visual inspection only from outside the cowling
Correct answer: With fuel on and the system pressurized, and again after run-up
Fuel system leak checks should be done with the system pressurized (fuel on) and confirmed after an engine run-up to ensure no leaks exist under operating conditions.
Question 4: What is the significance of the engine oil analysis (spectrographic analysis) in determining engine condition?
- It measures fuel contamination in the oil
- It detects trace metal elements that indicate wear of specific internal components (Correct answer)
- It confirms that the oil meets the manufacturer's viscosity specifications
- It is required by FAA for all annual inspections
Correct answer: It detects trace metal elements that indicate wear of specific internal components
Spectrographic oil analysis identifies metals like iron, chrome, aluminum, and copper, each associated with specific internal components, to trend wear before failure.
Question 5: An IA inspects a turbocharged engine's induction system. What failure would be particularly dangerous if missed?
- Slightly loosened intake hose clamps causing minor air leakage
- Cracks or leaks in the turbocharger housing allowing hot exhaust gases near fuel or airframe (Correct answer)
- Turbocharger impeller blade polishing from normal operation
- Slight discoloration of the compressor inlet from oil vapor
Correct answer: Cracks or leaks in the turbocharger housing allowing hot exhaust gases near fuel or airframe
Cracks in the turbocharger housing can allow extremely hot exhaust gases to escape near fuel lines, wiring, or the airframe, creating a severe fire hazard.
Question 6: What does the IA verify about an engine's crankcase breather system during an annual inspection?
- That the breather tube is routed overboard and free from ice or obstruction (Correct answer)
- That the breather connects to the carburetor heat system
- That the crankcase pressure equals manifold pressure at cruise
- That the breather filter is replaced every 100 hours
Correct answer: That the breather tube is routed overboard and free from ice or obstruction
The crankcase breather must be unobstructed and routed to vent overboard so that crankcase pressure can escape without building up and causing oil leaks or seal failure.
IA Engine & Powerplant Inspection Procedures 2
During an annual inspection, the IA checks the magneto-to-engine timing.
What is the risk of advanced timing?