PP 06

What is meant by flashover?. Weak spark delivery. Arcing inside the distributor. Low voltage failure. Stuck impulse coupling.

What is the difference between the right magneto and left magneto in the Bendix Shower of Sparks system?. Right side has retard breaker points. Left side has retard breaker points and is used for starting. Both have retard points. Neither has retard points.

What disconnects the retard points from the ignition circuit when operating on both magnetos?. P-lead. Starter switch. Distributor cam. Alternator relay.

What happens to the right magneto when starting an engine equipped with Shower of Sparks?. Fires first. Is isolated from ignition. Is off during starting. Delays spark to TDC.

How does an impulse coupling provide a hot spark for starting?. Opens breaker points wider. Uses spring action delayed until piston approaches TDC. Increases coil saturation voltage. Heats the plug tip.

What is the function of an impulse coupling during normal running?. Nothing. Maintains spark retard. Splits ignition timing. Boosts secondary voltage.

What disconnects the impulse coupling when the engine starts?. Starter switch. Flyweights. Distributor rotor. Tach generator.

What type of engines use magnetos with compensated cams?. Inline engines. Rotary engines. Some radial engines. Diesel engines.

Why is a compensated cam needed for that type of engine?. To improve cold starts. To compensate for elliptical travel of articulating rods. To reduce magneto heating. To increase dwell voltage.

At what speed in relation to the crankshaft does the compensated cam turn?. Same as crankshaft. ¼ crankshaft speed. ½ crankshaft speed. Twice crankshaft speed.

If an engine is equipped with a magneto that has a compensated cam, how fast does the rotating magnet turn in relation to the crankshaft?. Same speed as crankshaft. Twice crankshaft speed. ½ crankshaft speed. ¼ crankshaft speed.

What is meant by internal timing a magneto?. Adjusting spark plug gap. Setting ignition advance via mixture. Adjusting breaker points to begin opening at E-gap position. Setting the distributor gear lash.

What is meant by the E-gap of a magneto?. Economizer gap for mixture control. Engine gap for starter timing. Efficiency gap where points open for the strongest spark. Electrical ground gap in impulse coupling.

How can you find the neutral position of the magnet in a magneto?. It becomes magnetically noisy. The magnet will resist turning at that point. It spins freely without resistance. It becomes grounded through the P-lead.

When the cam follower wears, does the ignition timing drift early or late?. Early. Late. Unchanged. Cyclically varies.

What is the primary reason an aircraft engine requires dual ignition?. Easier maintenance. Reduced spark plug wear. Safety. Higher fuel economy.

What is meant by the P-lead of a magneto?. Primary lead that connects to the shutoff switch. Power lead that drives starter motor. Primary distributor wire. Pressure lead from induction system.

hat should be done if the breaker point felt pad does not have any oil on it?. Leave it dry. Apply spark plug anti-seize. Replace it. Add a few drops of light oil such as sewing machine oil.

What should be the appearance of a normally operating set of breaker points?. Blue and shiny. Dark and burnt. Silver, grey, or frosty in color. Polished chrome appearance.

What are the two types of spark plug electrodes used on aircraft engines?. Platinum and titanium. Ceramic and copper. Fine wire and massive electrode. Carbon and stainless steel.

What is meant by a staggered ignition system?. Spark plug firing sequence is randomized. Both plugs fire simultaneously. Spark plug near the exhaust valve fires first. All cylinders fire at half RPM.

What is one of the problems that results from shielding an aircraft ignition system?. Excess magneto lubrication. Sparks occur late. Prolonged spark duration causing electrode wear. Magnet rotor overheating.

What is meant by the reach of an aircraft spark plug?. Length of the center electrode. Length of the ceramic insulator. Length of the threaded area. Gap dimension between electrodes.

If a spark plug gasket-type CHT probe is installed, should a regular gasket also be used?. Yes, 2 gaskets required. No, thermometer gasket only. Only during cold weather. Only on magneto side plugs.

What is meant by a hot spark plug?. Higher current rating. Retains heat at core nose longer, used on low compression engines. Requires high-tension ignition only. Used only at high RPM.

What is meant by a cold spark plug?. Transfers heat to the cylinder head more easily. Has lower thread reach. Does not conduct electricity well. Is used for preheating.

Should a hot spark plug be used on high or low compression engines?. High compression. Both. Low compression. Depends on ambient temperature.

If one spark plug does not fire, what happens to the CHT of that cylinder?. Increases. Decreases. No change. RPM increases.

Of what two materials are fine-wire spark plug electrodes made?. Nickel and gold. Tungsten and copper. Platinum and iridium. Silver and cobalt.

Can a fine-wire spark plug produce a spark at a lower voltage than a massive electrode spark plug?. Yes. No. Only at altitude. Only at high RPM.

Of what material is a spark plug insulator made?. Aluminum. Ceramic. Magnesium. Carbon composite.

What is meant by an all-weather spark plug?. Extended gap spark plug. Higher power spark plug. ¾-inch thread size designed for higher altitudes. Corrosion-protected marine plug.

What is the normal color of deposits that form on the nose core insulator of a spark plug?. White. Light brown. Black. Silver.

How much wear is allowed on spark plug electrodes before replacement?. No wear permitted. 10%. 25%. One half of original size.

Why must spark plugs be kept in a numbered tray after removal?. o balance electrical load. To avoid contamination by mixing oil. To reinstall them in the next position in firing order to equalize wear. To allow faster ignition timing.