Aircraft Inspection PowerPoint

What is one of the primary tasks of an aircraft mechanic?

Inspections are one of the primary tasks of a mechanic.

What does 14 CFR 91.409 mandate regarding aircraft inspections?

14 CFR 91.409 mandates that all aircraft must undergo one of the four required inspections:

• Annual

• 100-Hour

• Progressive

• Inspection Program (Continuous)

What determines which inspection is required for an aircraft?

The type of aircraft and how it is operated will determine which inspection is required.

How common is welding in the A&P mechanic field today?

Welding used to be very common for A&P mechanics, but now it’s typically done only once or twice a year due to FAA regulations, making it a more specialized skill.

What should you know about an Annual Inspection in aviation maintenance? (List 4 things)

• Most common for light general aviation aircraft (e.g., Cessna)

• Must be completed every 12 calendar months

• Must be performed by an IA (Inspection Authorization)

• 14 CFR 43.15 and 43 Appendix D provide the inspection checklist and requirements

What does IA stand for, and who can hold it? (List 2 things)

• IA = Inspection Authorization

• Held by an A&P mechanic who meets FAA IA requirements

What does "12 calendar months" mean for inspection due dates?

The inspection is due by the end of the same month the following year

• Example: If done on July 1st, it's due by July 31st the next year

What do 14 CFR 43.15 and 43 Appendix D provide for the Annual Inspection? (List two things)

The checklist and regulatory requirements for performing the inspection

Who must the Annual Inspection be completed by, and who can perform other tasks? (List 2 things)

1. The inspection must be completed by the IA approving the aircraft

2. Access, cleaning, and repair tasks may be performed by other individuals

When is a 100-Hour Inspection required, and does it replace the Annual Inspection? (List 2 things)

• Required if the aircraft is used for compensation or hire (e.g., flight training, crop dusting, skydiving)

• It supplements but does not relieve or supersede the Annual Inspection requirement

Who can perform a 100-Hour Inspection?

It may be performed by an A&P mechanic

What does the 100-Hour Inspection cover?

It covers the same scope and detail as the Annual Inspection

What is the 10-hour overfly rule for 100-Hour Inspections? (List 2 things)

1. The inspection may be overflown by up to 10 hours without requiring a ferrying permit, but only if the aircraft isn’t making money during that time

2. The next inspection must be adjusted down by the amount overflown

   • Example: If it was due at 2100 hrs but performed at 2106 hrs, the next inspection is due at 2200 hrs (not 2206)

How many hours can an aircraft be overflown past its 100-Hour Inspection limit without requiring a ferrying permit, and under what condition?

• Up to 10 hours

• Only if the aircraft is not being used to make money during that time

What is a Progressive Inspection and when is it commonly used?

• It is basically an Annual Inspection broken up into smaller task areas

• Often used for aircraft operating as part of a business

• The entire aircraft must be fully inspected at least once within any 12-month period, even though the inspection is divided into segments

Who must manage or supervise a Progressive Inspection? (List 3 things)

1. An IA (Inspection Authorization)

2. A CRS (Certified Repair Station)

3. The aircraft manufacturer

A&Ps can perform individual tasks, but only under the supervision of one of the above

What does CRS stand for?

Certified Repair Station

What must be provided to the FAA for a Progressive Inspection? (List 3 things)

• A detailed inspection schedule

• Required inspection forms

• Proof that the operator possesses the necessary equipment to perform the inspections

What is an Inspection Program / Continuous Inspection, and when is it required? (List 4 things)

• A customized inspection for the unique aircraft and its operating conditions

• Must be approved by the FAA

• Required for:

  • Large aircraft

  • Multi-turbine engine airplanes

  • Turbine-powered rotorcraft

• Commonly used in commercial aviation

What can an Inspection Program / Continuous Inspection be approved under? (List 3 things)

• Part 121 – Maintenance requirements for scheduled air carriers (airlines)

• 135.411 – Maintenance rules for commuter and on-demand operations (aircraft with 10 or more seats)
  OR

• 135.419 – Approved Aircraft Inspection Program (AAIP); allows operators to create a custom inspection program, subject to FAA approval

What other sources can an Inspection Program / Continuous Inspection be approved under? (List 2 things)

• Manufacturer’s recommendations

• Designed by the owner/operator and approved by the FAA

Can turbine-powered rotorcraft use a different inspection?

Yes, turbine-powered rotorcraft may opt to use a different inspection

What are letter checks in an Inspection Program / Continuous Inspection, and what do they mean? (List 3 things)

• Letter checks refer to phases of inspection (e.g., A Check, C Check)

• Letters are not regulatory; they indicate time intervals

  • Example:

    • A Check = every 125 hours

    • C Check = every 3,600 hours

• Numbers identify what needs to be inspected, as defined by the inspection program

When is a Special Inspection required, and what kind of events trigger it? (List 2 things)

• A Special Inspection is required when an aircraft encounters unique environmental, operational, or maintenance conditions

• These events often involve hidden or masked damage

Where can guidance for Special Inspections be found?

1. Guidance can be found in ATA Chapter 5 – Unscheduled Inspections

   ATA stands for Air Transport Association, which standardizes technical documentation formats

Who can also provide inspection criteria for unusual circumstances?

Field Service Engineering can also provide inspection criteria for unusual circumstances

What is a conformity inspection, and when is it commonly performed? (List 2 things)

• A conformity inspection verifies that the physical aircraft is configured in accordance with its design data, modification data, and equipment list

• It will often occur when the aircraft is bought or sold

When is a conformity inspection expressly required?

It is expressly required when issuing the original airworthiness certificate or importing/exporting an aircraft

When must conformity be determined during aircraft service? (List 2 things)

• Whenever a part is installed on an aircraft, conformity must be determined

• Required inspections may identify conformity issues, but they are primarily focused on physical condition

Why is a conformity inspection important if you want to make money with your aircraft?

To legally operate an aircraft for commercial purposes

it must conform to its approved design and equipment data, which is verified through a conformity inspection

Which inspections require a checklist, and what are the options for creating one? (List 3 things)

• Annual and 100-Hour inspections require a checklist by regulation

• The checklist may be:

  • Of your own design

  • Provided by the manufacturer

  • **Obtained from another source

• Other inspections often have custom checklists that need to be completed

What must an aircraft conform to, and what documents apply if it's modified by? (List 6 things)

• The aircraft must conform to its Type Certificate

• Unless modified by:

  • STC (Supplemental Type Certificate)

  • AD (Airworthiness Directive)

  • SB (Service Bulletin)

  • Form 337 / Field Approval

  • Logbook entry (minor alteration / repair)

What is a Type Certificate?

A Type Certificate is FAA approval of the aircraft’s original design that meets airworthiness standards

What is an STC?

Supplemental Type Certificate

• An STC is an FAA-approved document authorizing a major modification to an existing aircraft, engine, or component.

• It certifies that the change complies with airworthiness standards.

What is an AD?

Airworthiness Directive

• An AD is a legally enforceable rule issued by the FAA to correct unsafe conditions in aircraft, engines, or components.

• Compliance with ADs is mandatory.

What is an SB (Service Bulletin)?

• An SB is a notice from the aircraft manufacturer recommending an inspection, repair, or modification.

• Not mandatory unless referenced by an AD or required by the operator's maintenance program.

What tools should be used for general inspection techniques? (List 3 things)

• A good flashlight

• Inspection mirrors (recommended to have several types)

• A magnifying glass

What should all items be inspected for during a general inspection? (List 5 things)

• General condition

• Apparent damage

• Proper operation

• Secure attachment

• Obvious defects caused by:

  • Weather

  • Friction

  • Overloading

  • Heat

  • Vibration

  • Maintenance

What is AC 20-106, and who is it designed to help?

• AC 20-106 outlines techniques used in aircraft inspections

• It is designed to familiarize:

  • Owners

  • Pilots

  • Student mechanics

  • Others with standard inspection procedures

How should a flashlight be used during fault detection inspection? (List 4 things)

• Orientation and intensity of the light affect inspection results

• Shine the light toward yourself at a 45-degree angle to help identify cracks

• Shine light along the surface to create shadows that reveal irregularities

  • Helpful for detecting dropped hardware

• Often used where there is adequate ambient lighting to help focus on a given area

What is the most practical and common form of welding inspection, and what NDT methods can also be used? (List 6 things)

• Visual inspection is the most practical and most common form of welding inspection

• Other NDT methods used to assist with welding inspection include:

  • Ultrasonic Testing (UT)

  • Radiographic Testing (RT)

  • Magnetic Particle Testing (MT)

  • Liquid Penetrant Testing (PT)

  • Eddy Current Testing (ET)

What are the characteristics of a good weld? (List 8)

1. Uniform in width

2. Even ripples that taper off

3. No burn marks

4. No overheating

5. No oxides more than ½” from weld

6. Free of gas pockets

7. Free of porosity

8. Free of inclusions

What is penetration in welding, and why is it important?

• Penetration is the depth of fusion in a weld

• It is the most important characteristic of a weld

What is required for proper penetration in a butt weld?

A butt weld should have 100% penetration equal to the thickness of the base metal

What is required for proper penetration in a fillet weld?

A fillet weld must have 25% to 50% penetration of the base metal

What are common welding issues related to weld quality? (List 4)

• Too much acetylene

• Cold welds

• Excessive heat

• Rapid cooling

What are the required characteristics of a properly formed butt weld? (List 4)

• Penetration must be 100% of the thickness

• Bead width should be 3 to 5 times the thickness

• Reinforcement height (bead height) should be ¼ to ½ of the thickness

• Gap between the two pieces should be ½ of the thickness

What are the required characteristics of a properly formed fillet weld? (List 4)

• Throat is the curved portion between the legs of the weld

• Throat depth should be 1⅓ to 1½ times the thickness

• Leg is the straight section from the root to the toe of the weld (basically the triangle’s height), and should be 2 to 3 times the thickness

• Penetration should be 25% to 50%

What does cracking adjacent to a weld indicate?

• Whenever a weld is made or after welding, cracking indicates that the part has cooled too quickly

• See AC 43.13, Chapter 4, Section 5 for more details

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What causes undercutting in a weld?

• Whenever a weld is made or after welding, undercutting is caused by excessive heat or slow travel speed

• See AC 43.13, Chapter 4, Section 5 for more details

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What does it mean if a weld sits on top and is not feathered?

• Whenever a weld is made or after welding, this indicates that there was insufficient heat

• See AC 43.13, Chapter 4, Section 5 for more details

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What happens if a weld bead is filed or ground?

• Whenever a weld is made or after welding, filing or grinding the bead reduces the strength of the joint

• See AC 43.13, Chapter 4, Section 5 for more details

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What must be done whenever a welded joint displays a defect?

• All of the old weld must be removed and the joint re-welded

• See AC 43.13, Chapter 4, Section 5 for more details

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What does a cold weld look like?

A cold weld has irregular edges and inconsistent penetration depth, showing poor fusion.

What does excessive heat look like in a weld?

Excessive heat causes pitting along the edges and leaves a weld with long, sharp ripples.

What happens if a part cools too quickly?

Cracks often form near the weld due to rapid contraction of the heated metal.

What happens when too much acetylene is used?

Too much acetylene makes the molten metal boil, creating centerline bumps and craters along the weld edges.

What is often done to parts after welding to relieve stress?

• Parts are often normalized after welding to relieve stresses

• See AC 43.13, Chapter 4, Section 5 for more details

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How are visual inspections of composite and bonded materials supplemented? (List 2)

• Visual inspections are supplemented with acoustic tests

• And NDT (Non-Destructive Testing) techniques

What is an acoustic test, and what tool is used to perform it?

• The acoustic test is often referred to as a tap test

• The tap test can be performed using a coin or a specialty tap hammer

What can a technician identify using the tap test, and how? (List 2)

• A technician can identify delamination and de-bonding

• By the change in sound:

  • A good area gives a sharp note

  • An affected area gives a dull, dead sound