CHAPTER 12 - AIRCRAFT TRANSPARENCIES Flashcards
CONSTRUCTION
What are the three construction categories for transparencies?
- Forward Windscreens
- Side Panels or Quarter Lights
- Cabin Windows and Ancillary Transparent Panels
OPTCAL DEFINITIONS
What are the three optical definitions when coping with transparencies?
Supercritical
Critical
Non-Critical
OPTICAL DEFINITIONS
When might the cabin windows need a higher degree of accuracy then normal?
For reconnaissance camera panels
MATERIALS
What 4 things help determine what transparency material is used?
- Physical and Mechanical Properties
- Ambient operating conditions
- Optical quality
- Application (weather capability, pressurised cabins etc.)
MATERIALS
What three material groups are most often used for transparency construction/
- Glass
- Acrylics
- Polycarbonates
MATERIAL
What transparency material must be annealed to relieve internal stresses?
It is often used in laminated transparency’s with other materials for safety reasons as well..
Glass
MATERIALS
What are ‘Perspex’, ‘Oro-glass 55’ and ‘Plexiglass’ all examples of?
Acrylics
MATERIALS
What are the two forms acrylic transparencies can be in?
- As-cast acrylics
- Stretched acrylics
MATERIALS
What is a strong advantage of acrylics?
Weather resistant
MATERIALS
Due to their relatively soft surface, what are acrylics prone to?
Scratch and impact damage
MATERIALS
Polycarbonates hold very similar properties to acrylics, however, what is their greatest additional property?
Higher Toughness and impact strength over a wide temperature range
MATERIALS
What are acrylics and polycarbonates susceptible to damage from?
Certain materials like de-icing fluids and solvents
CARE AND MAINTENANCE OF TRANSPARENCIES
How often are transparencies examined?
As part of flight servicing and scheduled maintenance activities
CARE AND MAINTENANCE OF TRANSPARENCIES
What is a method for assessing scratches on an aircraft transparency?
Ennis X50 microscope
CARE AND MAINTENANCE OF TRANSPARENCIES
Match the labels with the correct letter on the diagram..
Lower lens
Focus Ring
Depth Scale
Eyepiece
Cursor
Lens Barrel
Feet
Transparent Base
Viewing Lens
Internal Rotating Scale
A: Eyepiece
B: Viewing Lens
C: Internal Rotating Scale
D: Depth Scale
E: Lens Barrel
F: Cursor
G: Focus Ring
H: Lower Lens
I: Transparent Base
J: Feet
CARE AND MAINTENANCE OF TRANSPARENCIES
State the leading particular for the English X50 microscope..
Magnification
Field in View
Graduations on Focus Ring
Graduations on lens Scale
Max measuring range
Size Diameter
Weight
Magnification - X50
Field in View: 2.0mm
Graduations on Focus Ring: 0.1mm
Graduations on Lens Scale: 0.02mm
Max measuring range: 1.6mm
Size Diameter: 41.50mm x height: 122mm
Weight: 83gm
CARE AND MAINTENANCE OF TRANSPARENCIES
What pre-use checks should you do before using an English X50 microscope?
No obvious damage to the microscope
Ensure all the lenses are securely screwed into the lens barrel (lower lens is screwed into retaining ring and held in a fixed position)
Rubber eyepiece is fitted to the top lens
CARE AND MAINTENANCE OF TRANSPARENCIES
How do you take a measurement of depth using the Engis X50 microscope?
- Near the indentation, draw a chinegraph line
- Place the microscope over this line and adjust the focus ring until edge of the line is in focus
- Take a Reading from the engraved scale of the focus ring
- Without adjusting, place the microscope over the part of the indentation to be measure
- Re-adjust the focus until the bottom of the indentation is in focus
- Take a second reading
- Subtract the first reading from the second
Answer is the depth in mm
CARE AND MAINTENANCE OF TRANSPARENCIES
What is used to assess the depth of Crazing on a transparency?
Millimetre graph paper, a X10 magnifying glass and a suitable light source
CARE AND MAINTENANCE OF TRANSPARENCIES
After a surface chip occurs, what is a reasonable indication of internal splitting?
A whitened area
CARE AND MAINTENANCE OF TRANSPARENCIES
What are the measurements for a negligible chip?
Less than 1mm in diameter
CARE AND MAINTENANCE OF TRANSPARENCIES
What a re the measurements for a minor surface chip?
Less than 1mm in depth
Not exceeding 3mm in width
Not exceeding an area of 25mm squared
CARE AND MAINTENANCE OF TRANSPARENCIES
What is the acceptable size of an edge chip dependant on a transparency?
On its location - refer to the Aircraft Document Set