MIDTERMS CLEANING AND CORROSION

Question 1

The most widely used technique and is an
effective method for the detection and
evaluation of corrosion.

Using the sense of touch is also an
effective inspection method for the
detection o

Answer 1

VISUAL INSPECTION

Question 2

Four Categories of Visual Inspection

Answer 2

▪ Walkaround Inspection

▪ General Visual Inspection

▪ Detailed Visual Inspection

▪ Special Detailed Visual Inspection

Question 3

• • assesses the overall condition of the aircraft and its compliance with the security standards
• • performed by a human inspector by walking around on the ground below the aircraft

Answer 3

Walkaround Inspection

Question 4

– a routine inspection to locate and evaluate any damage, failure, or anomaly
– the human inspector requires additional equipment, such as ladders and cherry pickers

Answer 4

General Visual Inspection

Question 5

• intensive examination of a specific area, component, or system for the detection of damages - -
• some tools are required (ex. flashlight, magnifying glass, mirrors, or specialist measuring tools)

Answer 5

Detailed Visual Inspection

Question 6

• may be required for damage assessment of a specific item, installation, or assembly

Answer 6

Special Detailed Visual Inspection

Question 7

NDT method that utilizes the
principle of capillary action in which
liquid of suitable physical properties
can penetrate deep into extremely
fine cracks or pitting that are opened
to the surface without being affected
by the gravitational force

Answer 7

Liquid Penetrant Inspection

Question 8

During MPI inspection, magnetized
parts are coated with a solution made
up of fine magnetic particles coated
with fluorescent color, suspended in
alight oil or water bath

Answer 8

Magnetic Particle Inspection

Question 9

High frequency sound waves are
introduced into a material and they
are reflected back from surfaces or
flaws
- Reflected sound energy is displayed
versus time, and inspector can
visualize a cross section of the
specimen showing the depth of
features that reflect sound

Answer 9

Ultrasonic Inspection

Question 10

employs two transducers,

each placed in opposite sides
of the material being tested

Answer 10

Transmission Method

Question 11

sensitive
than transmission method;
identify defects by measuring
the time it takes amplitude
signals to travel between
different points or surfaces in
a material

Answer 11

Pulse Echo Method

Question 12

regularity of transmission can

be changed; used only when
one side of materials can be
accessed

Answer 12

Resonance Method

Question 13

CORROSION PRONE AREAS

Answer 13

-Exhaust Trail Access
-Battery Compartment Vent Openings
-Bilge Areas
-Lavatories, Buffets and Galleys
-Wheel Well and Landing Gear
-Water Entrapment Areas
-Engine Frontal Areas and Cooling
-Air Vents
-Wing Flap and Spoiler Recesses
-External Skin Areas
-Electronic and Electrical
Compartments

Question 14

NDT method, which uses penetrating
radiation
- Source of radiation can be from
radioactive sources, typically;
Iridium-192, Cobalt-60,
Caesium-137- emit gamma rays or
from a specially built machine that
can emit X rays

Answer 14

Radiography Inspection

Question 15

Particularly well suited for detecting
surface cracks but can also be used
to make electrical conductivity and
coating thickness measurements,

Answer 15

Eddy Current Inspection

Question 16

• Most common surface treatment of
  non clad aluminum alloy surfaces
• Anodized coating provides excellent
  resistance to corrosion
• Forms a hard oxide film on the
  surface by an electrolytic process

Answer 16

Anodizing

Question 17

Basic Steps In Anodizing

Answer 17

● Pre-Treatment
● Anodizing
● Sealing

Question 18

• Simple chemical treatment for all
  aluminum alloys to increase their
  corrosion resistance and to improve
  their paint bonding qualities
• Alodizing because of the chemical
  Alodine

Answer 18

Alodizing

Question 19

• 10% solution by weight of chromic
  acid, activated by a small amount of
  sulfuric acid, is particularly effective
  in treating exposed or corroded
  aluminum surfaces
• This treatment tends to restore the
  protective oxide coating on the metal
  surface

Answer 19

Chromic Acid Inhibitor

Question 20

-Less active chemical mixture for
surface treatment of aluminum is a
solution of sodium dichromate and
chromic acid
- Entrapped solutions of this mixture
are less likely to corrode metal
surfaces than chromic acid inhibitor
solutions

Answer 20

Sodium Dichromate Solution