Maintenance practices M7.8 Flashcards
What is the most common countersink angle
100°
How quickly must you quench a river after heat treating
No longer than 10-15 seconds to prevent intergranular corrosion
How long can you store rivets in the freezer
-18° 7 days
- 20° 20 days
What is a 470 rivet
Universal head
What is a 426 rivet
Countersunk head
How are rivet diameters measured
1/32 increments
How are rivet lengths measured
1/16 increments
What is rivet land
From the centre of the rivet to the edge of the material
2D-2.5D
What is rivet pitch
Centre of one rivet to the centre of the next
Min 4D
What is the spacing when talking about rivets
The spacing between rows of rivets
4D - 5D
What is the shpere of influence
5D
Guarantees a water tight joint
What is max spacing in a pressurised fuselage
6D
Coin dimpling is what angle
100°
What is the most common type of dimpling
Coin
When is dimpling used over countersinking
On material that is too thin to countersink
What is the most common cause of a cracked rivet tail
Incorrect heat treatment
When drilling rives use a slightly smaller drill then the hole size
Yes
What pin punch would be used to punch out the rivet after drilling
Same diameter as the diameter of the shank of the rivet
How much weight is saved by using a hi lite over a hi lok
15%
Where is the weight saved on a hi lite
Thread pitch run out
2 for hi lok 1 for hi lite
When installing cherry locks can you use any tool
No must be a cherry tool because they don’t have the driving anvil
When using cherry max can you use any air tool to install
Yes because they have the driving anvil to help the process
