7.18 Disassembley, Inspection, Reapir And Assembly Techs Flashcards
What are the two main types of defects that are inspected for
Metal fatigue and corrosion
What causes the condensation around aircraft’s
The changes in atmospheric pressure from ascending and descending
What causes metal fatigue
The repeated cycles of stress
How’s is the Majority of fatigue damage displayed
Small hairline cracks on the surface
What’s important to ensure when cleaning the aircraft
That the protective coverings are still in contact and that the cleaning fluids are approved by the manufacturer
What is can be added to metal structures to assist against corrosion
Calcium chromate or strontium chromate
What must be carried out if twisting or misalignment of aircraft structure is suspected
Kluge,ent or levelling checks must be carried out
What’s an endoscope made up from
Lenses and prisms fitted in a rigid metal tube
What diameter are endoscopes are commonly made to
6mm
Why do endoscopes use cold lighting
To prevent any sparks or ignitions caused by heat to occur which is important when being used in engines
What dimensions are light probes commonly made in ( diameter and stem lengths)
5 mm in diameter and 50 mm stem lengths
Why are inspections mirrors fitted with a light source
To avoid dazzling
What’s the most common type of magnification used in inspection mirrors
X2
What type of magnifying glass is used for viewing internal structures
A x8 magnification and a light probe fitted
What magnification size shouldn’t be used unless specified
x8
What are the four general types of actions that cause damage
• Mechanical action.
• Chemical action.
• Thermal action.
• Inherent metallic properties.
What are the two types of repairable damage
Non allowable and allowable
What are the two methods of paint removal
Chemical and mechanical
When is it appropriate to remove corrosions by abrasion using hands
When the corrosion is light
What are wire brushes made from
Stainless steel or aluminium oxide coated brushes
Why’s it important to ensure the metal doesn’t overheat when when grinding off corrosion
Because it may change the mechanical properties of the metal
What type of metal is the removal of corrosion using a grinder not suitable for
Aluminium alloys
When is abrasive blasting not recommended
For use internally
To obtain the best results when abrasive blasting what’s important to do with the positioning of the gun nozzle
Should be positioned so that the glass beads remove the corrosion in a width of approximately 25 mm
What’s the most common type of corrosion found on carbon steel
Red rust
Why can’t power tools be used on steel to remove corrosion
Because they may overheat due to steel being hard
What’s the hazards relating to titanium and silver chips
They are extremely flammable
Why are pretreatments carried out
To increase corrosion resistant properties and to give a surface food for adhesives
What type of metals are phosphate coatings used on
Steels
What are the main types of phosphate coatings
Manganese, zinc and iron
How thick is aluminium chromium oxide
0.001mm
What system does Boeing use for its paint finishes
Two layer paint system
What are the two main reasons for paint finishes
Aesthetics and protection
What are the three types of surface protection repairs and what are they for
Fixing- cleaning and maintenance of existing paint
Partial or total renewal- that the surface is removed of paint and a fresh cover is put on
Basic renewal- complete removal of paint and checked for corrosion
What general requirements should be taken into account when replacing a component
Correct number of people available, correct components, materials and work area
What should be considered when working on systems with capacitors in them
The capacitors must be allowed to stand without power supply recommended before any work is carried out as they’re high power supplies
What three things should be done before assembling a riveted joint
That the correct joining compounds used, the joints clean and the hole slightly oversize to allow for the expansion of the rivet shank
If a repair has been carried out to a control surface what additional actions will be required in addition to the repair
They must be checked for balance as they might have added weight from repair metal patches or paint
What’s the definition of a sealant
Sealing is a process that confines liquids and gasses within a given area
or prevents them from entering areas from which they must be excluded.
What are five functions of seals
Contain fuel, maintain cabin pressure, reduce fire hazards, exclude moisture, prevent corrosion
What’s a fillet seal and where’s it used
It’s used at structural joints and it’s used where maximum sealant of fuel liquids is required
What is a seal where sequent is sandwiched between two surfaces
Faying surface seals
What’s squeeze out time
The hours after application when the sealant can be squeezed out
What’s tackfree time
The time after the sealants applied that’s required to ensure that no residue is left on the fingers after touching it
What’s a seal plane
What can effect the cure time of sealants
Heat
What are methods of mixing sealants
Hand and machine
Whaf are 5 things that have to be checked before applying a sealant
What’s a semkit
Two part material injection
What tool must be used to remove sealants
Something made from hardwood or metal not harder than 2024 t3 treated
How is it possible to determine where fatugue might occur on aircraft structures
In places where repeated tress cycles occur
What are the three types of endoscope
Introscope, boroscope, fiberscope
What is anodising
Treating metals to form oxide coatings to improve performances of the metal
What’s secondary damage
When are injection seals used
To fill a channel. Or hole that occurs as a result of structural design
What’s a seal plane
The structural boundary on which the continuity of the seal is established
What’s a class a sealant
Brushable sealant
What’s a class B seal
A filleting sealant
What’s a class C sealant
A faying sealant
What’s a class D sealant
Hole filling sealant
What’s class E and f sealants
Sprayable sealants
At what Temperature will a sealant start bubbling when applied
120 degrees FARENHIET U STUPID CUNT NOT CELCIUS
What precautions must be made with silicone sealants
Should be stored separate from other sealants
Should have separate tools used
The use of mechanical freezers not CO2
What’s the three phase system used for applying silicone sealants
A brush coat is applied
A small fillet seal is applied
Final fillet seal applied
What type of seals are used for isolating fuel tank leakages
Faying surface seals
What’s used on fasteners to prevent leaking of liquids through fasteners
Small lightweight aluminium seal caps
What’s the maximum temperature a machine ,iced sealant compound can be stored at
-40 degrees FARENHIET U SILLT CUNY
How long Should you allow a sealant to thaw before use
5-10 mins in warm water
Or
30 mins in room temperature
Why’s it important for a sealant to thaw before application
Because a cold sealant doesn’t adhere correctly
What’s solvent are commonly used to clear sealants
MEK
What should the temperature of the structure be thawed to before having a sealant applied to it
50 degrees FARENHIET
