IGNITION AND STARTING PART 1

When using an electric starter motor, the current flow through it. is highest just before starter cutoff (at highest RPM). remains relatively constant throughout the starting cycle. is highest at the start of motor rotation.

If it is found that a shielded ignition system does not adequately reduce ignition noise, it may be necessary to install. a second layer of shielding. a filter between the magneto and magneto switch. bonding wires from the shielding to ground.

In a four-stroke cycle aircraft engine, when does the ignition event take place?. Before the piston reaches TDC on compression stroke. After the piston reaches TDC on power stroke. After the piston reaches TDC on compression stroke.

At what RPM is a reciprocating engine ignition switch check made?. 1,500 RPM. The slowest possible RPM. Full throttle RPM.

Which of the following are distinct circuits of a high tension magneto?. Magnetic, primary, and secondary. Magnetic, E-gap, and P lead. Primary, P lead, and secondary.

Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter overspeed during engine start by. stator nozzle design that chokes airflow and stabilizes turbine wheel speed. activation of a flyweight cutout switch. a preset timed cutoff of the airflow at the source.

What likely effect would a cracked distributor rotor have on a magneto?. Ground the secondary circuit through the crack. Fire two cylinders simultaneously. Ground the primary circuit through the crack.

A magneto ignition switch is connected. in series with the breaker points. parallel to the breaker points. in series with the primary capacitor and parallel to the breaker points.

Spark plug heat range is determined by. the reach of the spark plug. its ability to transfer heat to the cylinder head. the number of ground electrodes.

Defective spark plugs will cause the engine to run rough. during run up. during cruise. at all speeds.

If the ground wire of a magneto is disconnected at the ignition switch, the result will be the. affected magneto will be isolated and the engine will run on the opposite magneto. engine will stop running. engine will not stop running when the ignition switch is turned off.

If a spark plug lead becomes grounded, the. magneto will not be affected. distributor rotor finger will discharge to the next closest electrode within the distributor. capacitor will break down.

A spark plug's heat range is the result of. the area of the plug exposed to the cooling airstream. its ability to transfer heat from the firing end of the spark plug to the cylinder head. the heat intensity of the spark.

How are most radial engine spark plug wires connected to the distributor block?. By use of cable-piercing screws. By use of self-locking cable ferrules. By use of terminal sleeves and retaining nuts.

Pneumatic starters are usually designed with what types of airflow impingement systems?. Radial inward flow turbine and axial-flow turbine. Centrifugal compressor and axial-flow compressor. Double entry centrifugal outward flow and axial-flow turbines.

(Refer to Figure 5.) With power applied to the bus bar, what wire supplies standby power to the starter relay contact?. 4. 7. 8.

The purpose of staggered ignition is to compensate for. short ignition harness. rich fuel/air mixture around exhaust valve. diluted fuel/air mixture around exhaust valve.

What is the electrical location of the primary capacitor in a high-tension magneto?. In parallel with the breaker points. In series with the breaker points. In series with the primary and secondary winding.

Capacitance afterfiring of a spark plug is caused by. the stored energy in the ignition shielded lead unloading after normal timed ignition. excessive center electrode erosion. constant polarity firing.

Alignment of the marks provided for internal timing of a magneto indicates that the. reaker points are just beginning to close for cylinder 1. magneto is in E-gap position. Cylinder 1 is on TDC of compression stroke.

Inspection of pneumatic starters by maintenance technicians usually includes checking the. oil level and magnetic drain plug condition. stator and rotor blades for FOD. rotor alignment.

Generally, when removing a turbine engine igniter plug, in order to eliminate the possibility of the technician receiving a lethal shock, the ignition switch is turned off and. disconnected from the power supply circuit. the igniter lead is disconnected from the plug and the center electrode grounded to the engine after disconnecting the transformer-exciter input lead and waiting the prescribed time. the transformer-exciter input lead is disconnected and the center electrode grounded to the engine after disconnecting the igniter lead from the plug and waiting the prescribed time.

Which of the following statements is true?. The platinum and iridium ground electrodes used on fine wire spark plugs are extremely brittle and can be broken if they are improperly handled or adjusted. When gapping massive-electrode spark plugs, a wire gauge should be inserted between the center and ground electrodes while moving the ground electrode to avoid setting the gap too close. The platinum and iridium ground electrodes used on fine wire spark plugs are extremely strong and not easily broken when handled or adjusted.

The type of ignition system used on most turbine aircraft engines is. high resistance. low tension. capacitor discharge.

In a high-tension ignition system, the current in the magneto secondary winding is. conducted from the primary winding via the discharge of the capacitor. induced when the primary circuit is interrupted. induced when the primary circuit discharges via the breaker points.

When using a timing light to time a magneto to an aircraft engine, the magneto switch should be placed in the. BOTH position. OFF position. LEFT or RIGHT position (either one).

In the event a pneumatic start valve will not operate and the manual override must be used, the starter T-handle must be closed at scheduled starter drop out because. the starter will overheat. the starter will overspeed at a given N(2). the starter oil will be blown overboard.

What will be the result of increasing the gap of the breaker points in a magneto?. Retard the spark and increase its intensity. Advance the spark and decrease its intensity. Retard the spark and decrease its intensity.

Which of the following could cause damage to the nose ceramic or to the electrode of an aircraft spark plug?. Plug installed without a copper gasket. Improper gapping procedure. Excessive magneto voltage.

Great caution should be exercised in handling damaged hermetically sealed turbine engine igniter transformer units because. compounds in the unit may become a fire or explosion hazard when exposed to the air. some contain radioactive material. some contain toxic chemicals.

Magneto pole shoes are generally made of. laminations of high-grade soft iron. laminations of high-grade Alnico. pieces of high-carbon iron.

What will be the result of using too hot a spark plug?. Fouling of plug. Preignition. Burned capacitor.

What is a result of 'flashover' in a distributor?. Intense voltage at the spark plug. Reversal of current flow. Conductive carbon trail.

In a high-tension ignition system, a primary capacitor of too low a capacity will cause. excessive primary voltage. excessively high secondary voltage. the breaker contacts to burn.

When will the voltage in the secondary winding of a magneto, installed on a normally operating engine, be at its highest value?. Just prior to spark plug firing. Toward the latter part of the spark duration when the flame front reaches its maximum velocity. Immediately after the breaker points close.

Spark plugs are considered worn out when the. electrodes have worn away to about one-half of their original dimensions. center electrode edges have become rounded. electrodes have worn away to about two-thirds of their original dimensions.

(Refer to Figure 5.) Which malfunctions will allow the igniters to operate normally during start but be inoperative when tested?. Wire 10 is broken. Wire 14 or 15 is broken. Wire 12 is broken.

When removing a shielded spark plug, which of the following is most likely to be damaged?. Center electrode. Shell section. Core insulator.

Thermocouples are usually inserted or installed on the. front cylinder of the engine. rear cylinder of the engine. hottest cylinder of the engine.

(Refer to Figure 5.) When an external power source is connected to the aircraft,. the battery cannot be connected to the bus. both battery power and external power are available to the bus. the starter relay coil has a path to ground.

How does the ignition system of a gas turbine engine differ from that of a reciprocating engine?. One igniter plug is used in each combustion chamber. Magneto-to-engine timing is not critical. A high-energy spark is required for ignition.

A spark plug is fouled when. its spark grounds by jumping electrodes. it causes preignition. its spark grounds without jumping electrodes.

The spark occurs at the spark plug when the ignition's. secondary circuit is completed. primary circuit is completed. primary circuit is broken.

How many secondary coils are required in a low-tension ignition system on an 18-cylinder engine?. 36. 18. 9.