Foreign P General Written Test Study Guide

Key Concepts in AC Circuits

• Impedance: Term for combined resistive forces in AC circuits.
• Mutual Inductance: Basis for transformer operation and use of AC.
• Inductive Reactance: Opposition by a coil to alternating current.
  • Increases with frequency and coil size.

Capacitors and Inductors

• Capacitors in DC: Smooth voltage/current pulsations.
• Effective Voltage in AC: Less than maximum instantaneous.
• Capacitance: Directly proportional to plate area, inversely to plate distance.
• Parallel Capacitors: Total capacitance equals sum of individual capacitances.
• Series Inductors: Total inductance equals sum of individual inductances.

Power and Circuits

• Power Requirements: Two 3-amp lights need more power than a single equivalent load.
• Voltage Drop: Across resistors in parallel circuits remains constant.
• True Power vs Apparent Power: True power is less in reactive/inductive circuits.

Electrical Components

• Voltmeters: Connect in parallel for circuit testing.
• Diodes: Commonly used as rectifiers in power circuits.
• Induction: Transfer of electricity without connectors.

Transistors

• PNP Transistors: Conduct when base is negative compared to emitter.
• NPN Transistors: Conduct when base is positive compared to emitter.
• Zener Diodes: Used as voltage regulators.

Batteries

• Lead-Acid Batteries:
  • Fully charged ones resist freezing due to higher acid content.
  • Spilled electrolyte neutralized with sodium bicarbonate.
• Nickel-Cadmium (Nicad) Batteries:
  • Charged using constant voltage and varying current.
  • Thermal runaway caused by low resistance and high temperature.
  • Water addition at wrong charge state causes spewing.

Heat Treatment and Metals

• Annealing: Reduces internal stress in metals.
• Hardening: Increases wear resistance by chemical surface change.

Aircraft Structural and Weight Considerations

• Weight and Balance:
  • Reference datum affects arm measurements.
  • Empty weight includes unusable fuel.
  • Maximum weight includes useful load.
• Hydraulic and Pneumatic Components:
  • Use of bends in tubing prevents stress.

Non-Destructive Testing (NDT)

• Magnetic Particle Inspection: Detects surface/subsurface flaws.
• Dye Penetrant Tests: Identify cracks and surface defects.
• Ultrasonic Inspection: Suitable for many materials.

Regulatory and Compliance Information

• Airworthiness Directives (ADs): Notify of unsafe conditions.
• Type Certificate Data Sheets (TCDS): Key information on aircraft specifications.
• Supplemental Type Certificates (STCs): For design changes.

Aviation Regulations and Responsibilities

• 14 CFR Part 65: Certification and operating rules for mechanics.
• FAA Form 337: For documenting major repairs and alterations.
• Maintenance Records: Must be updated post-inspections and repairs.
• Mechanic Certification: Involves exams and ongoing experience.

Safety and Error Management

• Error Categories: Slips, mistakes, and violations.
• Error Management: Focus on prevention and safety intervention.