3.C
Aviation Merit Badge
Digital Resource Guide
Observe and/or participate in an aircraft maintenance activity.
Describe the maintenance schedule and requirements for an aircraft of your choice.
Routine maintenance for a Cessna 172, or any general aviation aircraft, is essential to ensure airworthiness and compliance with FAA regulations. Here’s a general overview:
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Preflight Inspections (All aircraft)
Frequency: Before every flight.
Performed by: Pilot in Command
Key Tasks:
- Visual check of the aircraft's exterior and interior using a preflight checklist.
- Sampling fuel to check for water or contaminants.
- Inspecting control surfaces, tires, and propellers for damage or wear.
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100-Hour Inspections (If aircraft is used for hire)
Frequency: Every 100 hours of flight time.
Performed by: A certified mechanic.
Key Tasks:
- Inspecting and servicing the engine, including oil changes.
- Checking flight control systems, avionics, and electrical systems.
- Inspecting the landing gear and brake systems.
- Verifying compliance with airworthiness directives (ADs).
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Annual Inspections
Frequency: Once per calendar year, required by FAA regulations regardless of flight hours.
Performed by: An FAA-certificated Airframe and Powerplant (A&P) mechanic with Inspection Authorization (IA).
Key Tasks:
- Comprehensive inspection of the entire aircraft.
- Checking structural integrity (e.g., wings, fuselage, and tail).
- Testing avionics, communication, and navigation systems.
- Reviewing maintenance records for compliance.
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Oil Changes
Frequency: Every 25–50 hours of flight time or every 4–6 months, depending on usage and oil type.
Key Tasks:
- Draining old oil and replacing it with fresh oil.
- Replacing the oil filter and inspecting for metal particles, which could indicate engine wear.
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Engine Maintenance
Scheduled Overhauls: Typically every 1,800–2,400 flight hours, depending on the engine model and manufacturer guidelines.
Tasks Include:
- Replacing worn components like pistons, bearings, and seals.
- Testing and recalibrating the fuel injection system or carburetor.
- Inspecting and cleaning spark plugs, replacing as needed.
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Airworthiness Directives (ADs)
Frequency: As issued by the FAA.
Purpose:Correct identified safety issues in specific aircraft models or systems.
Tasks Include:
- Implementing modifications or repairs outlined in the AD.
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Tires and Brakes
Frequency: Inspected regularly during preflight and routine maintenance.
Tasks Include:
- Replacing worn or damaged tires.
- Servicing or replacing brake pads and inspecting hydraulic lines.
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Propeller Maintenance
Frequency: Inspected during every 100-hour and annual inspection.
Tasks Include:
- Checking for nicks, cracks, or corrosion.
- Balancing and aligning the propeller.
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Corrosion Control
Frequency: Addressed during annual and other inspections.
Tasks Include:
- Inspecting the airframe and control surfaces for signs of rust or corrosion.
- Treating affected areas and applying corrosion inhibitors.
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Avionics and Electrical Systems
Frequency: Inspected during every 100-hour and annual inspection.
Tasks Include:
- Testing communication and navigation systems.
- Checking battery health and electrical connections.
Important!
A lot of work goes into making sure that your aircraft is “worthy” to fly. While they may not be as well-known as pilots, mechanics are an indispensable part of safe aviation!
Important!
A lot of work goes into making sure that your aircraft is “worthy” to fly. While they may not be as well-known as pilots, mechanics are an indispensable part of safe aviation!
Here is a video that will give you an example of a maintenance activity. To meet this requirement, you must actually observe (in person, or virtually via video if you do not have access to an aircraft and/or instructor) an aircraft maintenance activity. Watching this video does not complete requirement 3C.
You may know how to use a map and compass when hiking – do you know how to use a map and navigational equipment when flying?
