Week 4 Wooden Structure Flashcards
Requirement for Specialized maintenance to be carried by?
AMO
What reference species of wood are used in aviation?
Sitka Spruce
Solid Wood requirements:
Must be Kiln Dried
Specific Gravity not Less than 0.36
Slope of the grain not steeper than 1 :15
MUST be quarter sawn
Annular Rings requirements:
6 rings in ONE inch
Laminated Wood
Consist of two or more solid wood bonded together
Stronger but less flexible and used for curved shapes (WING SPAR)
Grains parallel to each other
Plywood
Constructed in veneers that are hot bonded together
Grain of veneers run at 90deg angle to each other
Grain of veneers run perpendicular to each other
Inspection for wood
Decay
Splitting
Shrinkage
Bond failure
Finish Failure (usually varnish)
Damage (Hangar Rash)
Acceptable and Ideal range of moisture
The acceptable moisture content of wood should be between 8% and 16%
Ideal is 10%-12%
Things that you always ask for yourself:
*IS THIS SPCIALIZED MAINTENANCE ?*
*IS THIS A MINOR OR MAJOR REPAIR ?*
*DO I HAVE THE APPROPRIATE DATA ?*
______ glue is used in very old wooden aircraft and already obsolete.
Casein Glue
_____ glue is also inappropriate of modern aircraft use, as it rapidly deteriorates in hot, moist environments.
Plastic Resin glue
______ glue that is highly water resistant glue that is a 2 part synthetic resin glue. Meets all FAA requirements for strength and is now the most commonly used adhesive in structural repair.
Resorcinol glue
______ glue is used in the construction of plywood and is not appropriate for field use.
Phenol-formaldehyde Glue
_______ glue that is very good working properties that requires less attention to joint quality. Durability is easily affected by humidity. Always follow manufacturer recommendations when using these products.
Epoxy Resins
(Time period) _______ is the useable life of the glue from the time it is mixed until the time it must be used.
Pot life
(Time period) ______ This is the allowable time between the application of the glue and the time the joint is assembled.
Open Assembly time
(Time period)_____ is the allowable length of time between assembly of the joint and the application of clamping pressure.
Closed Assembly time
(Time Period)_____ is the period of time during which the parts are being pressed together.
Pressing time
Typical size for the drain holes?
1/4” or 0.250”
