FAA Aviation Mechanic Powerplant (AMP)Ignition and Starting SystemsHard
A radial engine ignition system combines an induction vibrator with a retard breaker to produce a rapid series of high-energy sparks at a retarded timing position during engine start. This system is known as
- Aa shower of sparks ignition system
- Ba low-tension ignition system
- Can impulse coupling system
- Da capacitor discharge ignition system
Show answer & explanationAnswer & explanation
Correct answer: A. a shower of sparks ignition system
A shower of sparks system uses a vibrator (buzzer) to interrupt battery current rapidly, combined with a retard breaker in the magneto, to deliver a continuous series of sparks at a retarded timing position during cranking, providing better starting performance than a single spark from an impulse coupling.
Why the other options are wrong
- B. Low-tension ignition uses low-voltage primary distribution with a transformer at each plug; it is unrelated to the retard breaker/vibrator combination.
- C. An impulse coupling produces a single, retarded, high-energy spark per revolution using spring energy, not a continuous shower.
- D. Capacitor discharge systems are used on turbine engines for igniter plugs, not radial reciprocating engine start systems.
Shower of Sparks Ignition System
A starting ignition system that combines a vibrator (buzzer) with a retard breaker in the magneto to produce a rapid series of sparks at a retarded firing position during cranking, improving cold and normal starts.
- Vibrator rapidly interrupts battery current to feed the retard breaker points
- Retard breaker fires the magneto at a retarded position (safe for hand or starter cranking)
- Provides continuous sparking during cranking rather than a single impulse-coupling spark
Memory trick: A shower, not a drop — vibrator plus retard breaker makes sparks rain down at start.