Lewis Revision Cards Flashcards
What’s used to attach to fabric to wood
Dope
What’s the issue with dope
It’s very flammable
What’s added to dope to protect it from UV degradation
Aluminium
What’s type of fabric is used for aircraft
Polyester and glass fibre
What are the 3 inspection pannels
Spring, wood frames and zip
What are the two tools used to test the tension on fabrics? What ones better
Seyboth and maul.
Maul is better as it doesn’t puncture a hole in it
What type of repair is used for straight edge tears in fabrics
Herringbone stitches
What locking device can be reused
Shake proof washers
What are the most common materials used in locking wire
Copper and stainless steel
What’s the most common type of 1/4 turn fasteners
Dzus
What’s the difference between heavy and light duty Dzus fasteners
Heavy requires a grommet
If a internal wrenching bolt is installed in aluminium what must be considered and why
Placing a washer under the head must be considered to spread the pressure that’s being exerted onto the surface
At what temperature do low temp self locking nuts operate
Below 121 degrees
What’s the difference between AN and AC fittings
AN
Longer
Blue or black
Course thread
AC
Shorter
Grey
Finer thread
Which fitting ( AN or AC ) has recess
AN
What does the D mean marked on a hydraulic fitting
Made from aluminium
What does the S mean marked in a hydraulic fitting
That it’s made from CRES
When are permaswage repairs done
In quick in situ repairs
What do lay lines indicate on hose
Indicates any twisting
What’s the most common material used for inside of tubing and why
Teflon because it’s chemically compatible with most fluids
What’s the low pressure, medium pressure and high pressure of hose
Low- 600
Medium- up to 3000psi
High- over 3000psi
When wouldpotted repairs used for
Holes up to 2.5cms
What’s the issue with radiography
They can’t detect delaminations
What’s the carbon percentage In
Low carbon steel
Medium carbon steel
And high carbon steel
0.1-0.3
0.3-0.5
0.5-1.05
What class a screws usually
2
What are the 3 general grades of stainless steel
Austenitic
Ferritic
Martensitic
What is an AN426
Countersunk head rivet
What’s a AN470
Universal head rivet
Why are countersunk rivets more commonly used on aircraft surfaces
Aerodynamics
What does 3xxx
Manganese
What’s 5xxx
What’s 4xxx
Silicon
What are the two common nickel alloys
Morel and inconel
What is the reducing agent in corrosion
Anode
What’s the most common rivet type used
2117
Two types of fibreglass
E and s glass
What’s fibreglass made up from
Silica glass
What’s aramid repaired with
Fibreglass
Why isn’t boron commonly used on aircraft
Because it’s very expensive and can be dangerous
Where’s ceramic used
In high temperatures
What’s the negative of pre impregnated fabrics
Must be frozen
What’s the major diameter and minor diameter on a male thread
Major - crest to crest
Minor- root to root
What’s the major and minor diameter in a female thread
Major is root to root
Minor is crest to crest
What’s the thread angle of British thread forms, what ones the anomaly and what’s the degrees of that
55 degrees
Ba anomaly and angle of 47.5
What’s the thread angle of American thread forms
60
What’s the thread angle of unified thread forms
60
What does the x mean on the top of a bolt head
That it’s a steel bolt
What does the dash on top of a bolt head mean
That it’s made of a CRES
What does the triangle mean on top of a bolt
Shows it’s a close tolerance bolt
What does the double dashes on a bolt head mean
That it’s made from aluminium
When are stepped studs used
In softer materials
What’s the diameter of rivets measured in
1/32 of an inch
What’s the length of the rivet measured in
1/16th
How’s a 1100 rivet identified
No marking
With letter A (absent)
How’s a 2117 rivet identified
Letters AD
A dimple
What’s a 5056 rivet identified by
The letter B
Has a cross on it
How’s a 2017 rivet identified
A dot
Identified with a D
How’s a 2024 rivet identified
DD
Double dash
What’s the economic advantage of cherry max rivets over cherry locks
Cherry max require one size puller
What type of metals are more succesptible to exfoliation
Wrought
What’s the difference between a high lock and a high lite fastner
High lite are lighter
What does PHDAN stand for
Physically dangerous
Where is magnesium used in aircraft
Landing gear/wheels
For rigid fluid lines what’s classified as
High pressure
Medium
Low
High is over 1500
Medium is below 1500
Low is suction and return
How’s tubing size determined
By outside diameter in 1/8ths of an inch
Where’s aluminium obtained from
Bauxite ore
What’s the flair angle of an AN fitting
37 degrees
What’s the flare angle of AC fittings
35 degrees
How are flareless fittings sealed
Ball and bush principle
What are the two forces bearings are subjected to
Axial and radial
What’s the issue of using ball bearings
They can only withstand light radial loads
What does F, O and H stand for
Fabricated, annealed and strain hardened
What two materials are used in cables
Aluminium and copper
What happens to the ability of cables to carry a current when there enclose with other cables
They can’t carry as much current due to it will produce heat
What are thermocouples made from
Chrome land alumel
When are bevel gears used
When a drive needs to be transmitted to a different axis
Where are planetary gears used in aircraft
As reduction gearing in aircraft engines
Benefits of using a roller bearing over a ball bearing
Roller will take more radial loads due to larger contact area
What are the +’s of synchronous belts
Low maintenance
Non slip
Non lubricated
Which of the following cables are flexible and which are non flexible
1x7
1x19
7x7
7x19
1x7 non flexible
1x19 non flexible
7x7 flexible
7x19 flexible
Benefits of using lock clad cable
Prevents sag
Prevents vibration
What’s the role of a cable turnbuckle
Facilitates cable tensioning
What’s the use of fairleads
Prevents the wire from coming in contact with the structure
If a turnbuckle had a groove on it what does that indicate
That it’s a left hand thread
What’s the advantage of a helical gear over a spur gear
They’re quieter and can carry heavier loads
Advantages of multiple pulley drives
Allow change in speed
