Reciprocating Engine Ignition Systems Flashcards
7 cards from real AMT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Reciprocating Engine Ignition Systems flashcards as text
What is the primary purpose of the impulse coupling on a magneto?
Answer: Provide a retarded and intensified spark during engine starting
The impulse coupling temporarily retards ignition timing and snaps the magnet past the neutral position to produce a strong spark at low starting speeds.
Which ignition system component prevents a spark plug from firing at the incorrect time due to residual magnetism?
Answer: Condenser
The condenser absorbs the collapsing magnetic field energy, preventing arcing at the breaker points and ensuring sharp primary circuit cutoff.
On a dual-magneto ignition system, the 'BOTH' position on the ignition switch is used during normal flight because it:
Answer: Reduces fuel consumption by providing complete combustion
Firing two spark plugs per cylinder from separate magnetos produces more complete combustion, improving efficiency and providing redundancy.
A magneto's 'E-gap' refers to the position of the rotating magnet when:
Answer: Magnetic flux through the coil core is changing most rapidly
E-gap (efficiency gap) is the rotor position at which flux change in the core is at maximum, generating the highest possible primary voltage before points open.
What type of spark plug would most likely be used in a high-compression aircraft engine to resist fouling?
Answer: Short-reach, cold heat range plug
Short-reach, cold heat range plugs transfer heat away quickly, reducing pre-ignition risk in high-compression engines while the short reach avoids interfering with pistons.
During a magneto check at runup, a drop of more than the manufacturer's specified RPM when switching to one magneto indicates:
Answer: A possible defective magneto or fouled spark plug on that side
An excessive RPM drop on one magneto suggests that magneto or its associated plugs are not functioning correctly, requiring maintenance investigation.
Which of the following describes correct procedure when grounding a magneto for maintenance?
Answer: Connect the P-lead to aircraft structure to disable ignition output
The P-lead grounds the primary circuit through the ignition switch; ensuring it is connected to ground (switch OFF or lead grounded) disables the magneto safely.