6.3.3 Fabrics Flashcards
What is the warp?
Warp threads run the length of the fabric
In which direction must the warp threads be in relation to the direction of flight?
Parallel.
What is the fill?
Fill threads run perpendicular (90°) to the warp fibres. The fill threads interweave with the warp threads to create the reinforcing cloth.
What is the selvage edge?
The tightly woven edge, parallel to the warp direction, and prevents the threads from unravelling.
What is the bias?
Bias is the fibre orientation that runs at a 45° angle to the warp threads.
What does the bias facilitate?
Manipulation of the fabric to form contoured shapes and can be stretched along the bias.
When was nitrate dope created?
1916
What was the major drawback of nitrate dope?
Extremely flammable
How was the issue of nitrate dope not being flame resistant and butyrate dope not being as adhesive overcome?
They were combined, with a nitrate dope first followed by the butyrate.
Where is glass fibre used?
Normally fitted to the mainplane and tailplane in a spanwise direction.
How must aircraft fabrics be stored?
20 degrees c, in clean and dry conditions away from direct sunlight.
What are some examples of what can be found when inspecting fabrics?
Loose tape
Brittleness
Tears
Missing stringing
Mice and insects
Mould
What three types of inspection panel are there in fabric coverings?
Wood frames
Zip Panels
Spring panels
Where should punch tests be carried out on fabric?
On exposed fabric where there is a crack or chip in the coatings.
What are the two types of fabric tester?
Maule
Seyboth
How does the maule tester work?
Measures breaking strength, if the fabric doesn’t break it is airworthy.
Why is the seyboth tester not as popular?
Because it punctures a small hole
What is the safe life of a fabric?
5-10 years
What does the rate of deterioration depend on?
Type of operation
Climate
Storage
What can excessive tension lead too?
Warping of the longerons, ribs and trailing edges
What can cause wrinkles in the fabric?
Moisture
Too thick doping
Aircraft moved from cold hangar to warm outside
When repairing what is a herringbone stitch used for?
Used for repairing straight cuts or tears which have sound edges.
Once a herringbone stitch has been completed what happens next?
25mm serrated tape must be placed over the top and doped.
Where is a darning repair used?
Irregular holes or jagged tears in the fabric.
