AME - Aircraft Maintenance Engineer Maintenance Practices and Materials Questions and Answers — Questions and Answers
Question 1: An AME is performing a visual inspection on a section of aluminum alloy aircraft skin and observes small, white or gray powdery deposits. This is indicative of which type of corrosion?
- Filiform corrosion
- Fretting corrosion
- Pitting corrosion
- Surface corrosion (Correct answer)
Correct answer: Surface corrosion
Surface corrosion is the most common type of corrosion on aluminum and magnesium alloys. It is characterized by a uniform attack on the surface, which first appears as a general dulling or etching of the surface, and then progresses to form white or gray powdery deposits.
Question 2: When performing a dye penetrant inspection, what is the primary purpose of the developer?
- To clean the surface of the material before applying the penetrant.
- To draw the penetrant out of the discontinuity by capillary action, making it visible. (Correct answer)
- To etch the surface of the material to open up small cracks.
- To remove excess penetrant from the surface after the dwell time.
Correct answer: To draw the penetrant out of the discontinuity by capillary action, making it visible.
In a liquid dye penetrant inspection, the developer acts as a blotter, drawing the penetrant that has seeped into a crack or flaw back to the surface. This action, known as capillary action, makes the indication visible against the contrasting background of the developer.
Question 3: A castellated nut has been torqued to the minimum specified value, but the cotter pin hole does not align with any of the slots. According to standard maintenance practices, what is the correct procedure?
- Loosen the nut to the previous slot to align the hole.
- Replace the washer with a thinner one and re-torque.
- Tighten the nut slightly to align with the next available slot, without exceeding the maximum torque value. (Correct answer)
- Drill a new cotter pin hole in the bolt.
Correct answer: Tighten the nut slightly to align with the next available slot, without exceeding the maximum torque value.
Standard practice dictates that after reaching the minimum torque value, you may tighten the nut further to align the cotter pin hole with the next slot, as long as the maximum specified torque is not exceeded. Loosening the nut would result in it being under-torqued.
Question 4: Which of the following non-destructive testing (NDT) methods is most suitable for detecting subsurface defects in a non-ferrous material like an aluminum wing spar?
- Magnetic Particle Inspection
- Dye Penetrant Inspection
- Eddy Current Inspection
- Ultrasonic Inspection (Correct answer)
Correct answer: Ultrasonic Inspection
Ultrasonic inspection is highly effective for detecting subsurface flaws like cracks and corrosion in both ferrous and non-ferrous materials. Magnetic particle inspection only works on ferromagnetic materials. Dye penetrant is for surface-breaking defects only. Eddy current is primarily for surface and near-surface defects.
Question 5: During a maintenance task, an AME needs to safety wire a series of three bolts on an engine accessory case. What is the correct procedure for installing the safety wire?
- The wire should be installed so that it pulls the bolt head in the loosening direction.
- A single wire should be used, passing through each bolt head and twisted only at the end.
- The wire should be routed in a way that the tension on the wire counteracts the tendency of the bolt to loosen. (Correct answer)
- No more than two bolts should ever be secured with a single piece of safety wire.
Correct answer: The wire should be routed in a way that the tension on the wire counteracts the tendency of the bolt to loosen.
The fundamental principle of safety wiring is to install the wire in such a manner that it creates a tightening force on the fastener if it starts to loosen. This is often referred to as wiring 'righty-tighty'. While a common rule of thumb is to safety no more than three bolts together, the most critical aspect is the direction of pull.
Question 6: An aircraft structural repair requires joining a carbon steel fitting to an aluminum alloy bulkhead. To prevent galvanic corrosion, what is the most critical action the AME must take?
- Apply a thick layer of grease between the two surfaces.
- Use aluminum rivets to attach the steel fitting.
- Ensure a metal-to-metal contact for proper electrical bonding.
- Isolate the dissimilar metals with a suitable non-conductive barrier or sealant. (Correct answer)
Correct answer: Isolate the dissimilar metals with a suitable non-conductive barrier or sealant.
Galvanic corrosion occurs when two dissimilar metals are in contact in the presence of an electrolyte. To prevent this, the metals must be electrically isolated from each other. This is typically achieved by applying a layer of primer, sealant, or a non-conductive material like vinyl tape between the surfaces.
AME - Aircraft Maintenance Engineer Maintenance Practices and Materials Questions and Answers
An AME is performing a visual inspection on a section of aluminum alloy aircraft skin and observes small, white or gray powdery deposits.
This is indicative of which type of corrosion?