Transparencies Flashcards
What are the 10 parts of an Engis X50?
Eyepiece
Viewing lens
Internal rotating scale
Lens barrel
Cursor
Depth scale
Focus ring
Lower lens
Transparent base
Feet
3 most common materials used in transparencies
Glass
Acrylic
Polycarbonate
Whats the benefit of polycarbonate in comparison with acrylic for transparencies?
Tougher and stronger, can withstand higher temperatures
Pre use check of an Engis X50
Ensure no damage
Ensure lenses are secured in
Fit rubber eyepiece
How is glass prepared for aircraft transparencies?
Annealed then thermally or chemically processed to increase strength
Two different types of chip on aircraft transparencies?
Surface chip
Edge chip
Two different types of surface chip on aircraft transparencies and allowable dimensions?
Negligible chip - less than 1mm diameter
Minor surface chip - less than 1mm depth, no more than 3mm width, not exceeding 25mm squared
What to do if Engis X50 reading is suspect?
Check against a known depth and replace if inaccurate
Whats the magnification of the Engis X50?
X50
What the field of view of Engis X50?
2.0mm
Whats the graduations on focus ring on Engis X50?
0.1mm (0.004 in)
What are the graduations on lens scale on Engis X50?
0.02mm (0.0008 in)
Whats the max measuring range on Engis X50?
1.6mm
Whats the size of Engis X50?
Dia - 41.5mm X Height - 122mm
Whats the weight of Engis X50?
83gm
3 categories of aircraft transparencies?
Forward windscreen and centre panels
Side panels or quarter lights
Cabin windows and ancillary transparent panels
3 classifications of areas of vision according to their optical effect?
Supercritical
Critical
Non-critical
Aircraft designers select transparency materials based on:
Physical and mechanical properties
Ambient operating conditions
Optical quality
Application
- Pressurised cabins
- Non-pressurised cabins
- All weather capabilities
What is one full rotation of the focus ring in an Engis X50?
8.0mm
What do you use to measure the depth of crazing in a transparency?
Millimetre graph paper
A X10 magnifying glass
Suitable light source
How to measure depth of indentation with an Engis X50?
Draw chinagraph line on clean area adjacent
Adjust focus ring until line is in focus, take measurement
Without adjusting focus ring, move over the indentation
Readjust focus until bottom of indentation is clear, take measurement
Subtract first reading from second, result is depth in mm
How to assess distortion?
A grid board positioned in front of transparency. Any distortion can be observed from behind transparency identified by a distorted line on the grid board.
How to identify delamination in transparencies?
Moisture ingress shows as cloudy areas
Delamination around edges can show as smooth edge or rough edge
Doubtful cases, shine a light through between two lines, if delaminated, an additional line will show.
Whats controlled delamination?
Where release tapes are built into edges of panels to permit flexing in service
How do you clean transparencies?
Coarse dirt washed off with water
Do not rub
Remove grease by swabbing with photographic grade wool saturated with aircraft transparency cleaner
Allow to air dry or swab dry
Wipe glass surfaces with chamois leather
Outline transparencies Polishing prcedures
Reference AMM
- Ensure all dirt cleaned
- light hand pressure
- renew polish cloth frequently
- avoid accumulating polishing materials in recesses or frame abutments
What to do with a superficial scratch?
Glass - Acceptable subject to aircrew approval
Plastic - remove with reference to ADS
What to do with a moderate scratch?
Glass - acceptable subject to aircrew approval
Plastic - removed, consult ADS
What to do with deep scratches?
Glass - Can cause cracks, should be replaced
Plastic- consult ADS to establish maximum permissible damage then remove using approved procedures if applicable
How should transparencies be stored?
Cool, dry, well ventilated environment.
Keep away from vapours and abrasives
6 types of damage to transparencies
Physical damage
Crazing
Delamination
Cracks
Bubbling
Discolouration
Whats ADS?
Aircraft Document Set
Two types of sealant?
Polysulphide
Silicones
What temperature range do polysulphide sealants work at?
-55 to +120 degrees centigrade
What are polysulphide sealants resistant to?
UV Light
Fuels
Oils
Hydraulic fluid
What does RTV stand for?
What are they for?
Room temperature vulcanising (sealants)
Used in high heat areas and electrical components
Whats curing and non curing sealants?
Curing form a tough rubbery solid resistant to weather, moisture and ozone.
Non curing are used for integrated fuel tanks as they swell on contact with fuel producing a tighter seal.
Name the 3 procedures which may be carried out to repair transparent plastic panels
Repair scratch or score
Apply external patch
Apply insertion patch
Whats perspex, oro glass and plexiglass another name for?
Acrylic
What material can be treated by stretching to impart superior crack/craze resistance? (Transparencies)
Acrylic
What material can only be used to clean an acrylic transparency?
Micro mesh
