Airframe and Powerplant

There are a number of topics that an Aviation Maintenance Technician, or Airframe & Powerplant mechanic studies, seperated into three major categories.

• General
• Airframe
• Powerplant

Each has their own subtopics.

General Studies

The following are the chapters from FAA's 8083 General textbook, which is becoming the main textbook taught in FAR Part 147 AMT schools.

1. Mathematics
2. Aircraft Drawings
3. Physics
4. Aircraft Weight and Balance
5. Aircraft Materials, Processes, and Hardware
6. Aircraft Cleaning and Corrosion Control
7. Fluid Lines and Fittings
8. Inspection Fundamentals
9. Hand Tools and Measuring Devices
10. Basic Electricity
11. Safety, Ground Operations, and Servicing
12. Publications, Forms, and Records
13. The Mechanic Certificate
14. Human Factors

Airframe

The subjects under Airframe, taken from the contents of Aviation Maintenance Technician Handbook - Airframe (FAA-H-8083-31)

1. Aircraft Structures
2. Aerodynamics, Aircraft Assembly, and Rigging
3. Aircraft Fabric Covering
4. Aircraft Metal Structural Repair
5. Aircraft Welding
6. Aircraft Wood and Structural Repair
7. Advanced Composite Material
8. Aircraft Painting and Finishing
9. Aircraft Electrical System
10. Aircraft Instrument Systems
11. Communication and Navigation
12. Hydraulic and Pneumatic Power Systems
13. Aircraft Landing Gear Systems
14. Aircraft Fuel System
15. Ice and Rain Protection
16. Cabin Environmental Control Systems
17. Fire Protection Systems

Powerplant

Part 1: Aircraft Engines

Requirements of an aircraft engine:

1. Power and weight, aircraft powerplants need to be powerful but light in weight.
2. Fuel Economy, engines must be designed with fuel economy in mind
3. Durability and Reliability, must be durable enough to power a plane reliably
4. Operating Flexibility
5. Compactness, engines must be compact to fit in an aerodynamic nacelle or pod in front of the pilot in the case of a single engine plane.

Types of engines: Opposed (O type,) V-type, Radial Engines

Design and construction of reciprocating engines; it's parts. The basic major components of a reciprocating engine are the crankcase, cylinders, pistons, connecting rods, valves, valve-operating mechanism, and crankshaft.

Aircraft engines are divided into sections: nose, crankcase and accessory section.

The crankcase is the foundation of the engine and is usually made out of cast or forged aluminum and is the main support of the entire engine. The engine mounts connect the crankcase to the aircraft. It split into 2 halves that hold the crankshaft and camshaft between them with the nose at the front and the accessory case mounted to the rear. The separate cylinders are mounted to the crankcase on precisely machined surfaces that cylinders are mounted to are called cylinder pads. On the typical opposed engine, the cylinders are mounted to the side, and the induction system manifold connected to the bottom.

The crankcase accessory section is a separate section at the rear can be one piece with means for mounting the accessories, such as magnetos, carburetors, fuel, oil, vacuum pumps, starter, generator, tachometer drive, etc. required to run the engine or use the engine output to drive other systems like the electrical system. The accessories are driven by gears.

The front nose section on the crankcase is where the propeller mounts either directly to an attachment on the end of the crankshaft, or via a set of reduction gears and a propeller governor for high powered engines.

Part 2: Engine Fuel and Fuel Metering Systems

A modern aircraft engine has electronic controls that that accurately control the flow of fuel to the engine. See FADEC

The basic parts of a fuel system include tanks, boost pumps, lines, selector valves, strainers, engine-driven pumps, and pressure gauges. Aviation fuel is covered in the general section

External Links

Aviation Mechanic testguide – General, Airframe, and Powerplant (PDF)

CFR 14:Part 65 CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Subpart D—Mechanics