Engine Ignition & Electrical

Proper maintenance, inspection, and timing of a reciprocating engine ignition system are essential for reliable engine operation. Maintenance procedures include checking magneto internal timing and E-gap, timing the magnetos to the engine, performing operational ignition system checks, and inspecting ignition leads and harnesses for defects. Accurate adjustment and careful testing help ensure that the ignition … Read more

Aircraft powerplant electrical systems depend on effective bonding and grounding to ensure safe and reliable operation. Proper bonding and grounding connections provide low-resistance current return paths, reduce electromagnetic interference, protect against static electricity and lightning effects, and help maintain the performance of electrical and electronic equipment. The following sections explain the principles, installation methods, and … Read more

The magneto, a special type of engine-driven alternating current (AC) generator, uses a permanent magnet as a source of energy. By using a permanent magnet to provide a basic magnetic field, a coil of wire to provide concentrated lengths of conductor, and relative movement between the magnetic field and conductor, current is generated in the … Read more

Proper wire and cable preparation is essential when maintaining engine ignition and electrical systems. Electrical connections must be correctly prepared to ensure reliable current flow, mechanical strength, and resistance to vibration. Cutting, stripping, crimping, and splicing procedures require the correct tools and techniques to prevent conductor damage and connection failures. Cutting Wire and Cable To … Read more

Aircraft powerplant electrical systems rely on properly secured wire groups and bundles to ensure reliable operation under vibration, heat, and other operating conditions. Correct lacing and tying techniques help prevent wire movement, chafing, and insulation damage while simplifying inspection and maintenance. The following sections describe and illustrate recommended procedures for lacing and tying wire groups … Read more

Proper inspection and maintenance of spark plugs and ignition system components are essential for reliable engine operation and maximum ignition system performance. Regular servicing helps prevent fouling, excessive electrode wear, ignition failures, and harness-related faults while ensuring efficient combustion and dependable engine starting. This section describes common spark plug problems, recommended inspection and reconditioning procedures, … Read more

Auxiliary ignition units are used to improve ignition during reciprocating engine starting, when low cranking speed may prevent a magneto from producing sufficient voltage for reliable spark plug firing. These systems provide a stronger starting spark while retarding ignition timing to help prevent engine kickback. Common auxiliary ignition systems include booster coils, impulse couplings, and … Read more

The satisfactory performance of any modern aircraft depends to a great degree on the continuing reliability of electrical systems and subsystems. Improperly or carelessly installed or maintained wiring can be a source of both immediate and potential danger. The continued proper performance of electrical systems depends upon the knowledge and technique of the mechanic who … Read more

The basic requirements for reciprocating engine ignition systems are similar, regardless of the type of engine. All ignition systems must deliver a high-tension spark across the electrodes of each spark plug in each cylinder of the engine in the correct firing order. The spark occurs in the cylinder at a predetermined number of degrees before … Read more