Aircraft Maintenance Engine & System Repairs Flashcards

What is the purpose of the chip detector in an aircraft turbine engine lubrication system?

Answer: Detect ferrous metallic particles indicating internal wear or failure

Chip detectors use a magnetic plug to capture ferrous metal particles, providing early warning of internal component wear or imminent failure.

A reciprocating engine cylinder is found with a scored barrel during overhaul. The correct repair procedure per FAA standards is to:

Answer: Hone the cylinder to the next oversized dimension and install oversize pistons if within limits

Scored cylinders may be honed to the next acceptable oversize dimension if the final diameter remains within the manufacturer's published limits, requiring matched oversize pistons.

When leak-checking a turbine engine fuel manifold after maintenance, the test medium specified by most manufacturers is:

Answer: Nitrogen gas at 1.5 times operating pressure

Nitrogen is used for pressure leak checks because it is inert and non-flammable, and testing at 1.5 times operating pressure verifies a positive margin of safety.

An aircraft engine oil cooler bypass valve opens prematurely at low oil temperatures. The effect on the engine will be:

Answer: Oil that remains too cool, increasing viscosity and reducing lubrication effectiveness

A bypass valve that opens prematurely routes cold oil around the cooler, keeping it too viscous, which reduces flow to bearings and impairs lubrication at low temperatures.

During an engine test cell run following overhaul, engine oil consumption is found to be higher than the maximum limit. The probable cause is:

Answer: Worn or improperly installed piston rings or valve guides

Excessive oil consumption after overhaul is most commonly caused by worn or incorrectly installed piston rings or worn valve guides allowing oil to enter the combustion chamber.

Which maintenance action requires an Airworthiness Directive (AD) review before performing work on an aircraft engine?

Answer: Replacing a component that has an AD applied to that part number or engine model

Before replacing any component, the technician must check for applicable ADs because an AD may require specific part numbers, procedures, or compliance times affecting the repair.

A turbine engine anti-icing system fails to activate during a ground functional test. After verifying the cockpit switch is serviceable, the technician should next check:

Answer: The pressure regulating and shutoff valve for the bleed air anti-ice circuit

The pressure regulating and shutoff valve controls bleed air flow to the anti-ice system; a faulty or stuck-closed valve is the most common cause of anti-ice system failure after ruling out the cockpit switch.