Mod 7 Essays (Mechanical) Flashcards
What is the difference between direct and indirect riveting
pg 12 7.8 Riveting
Riveting is used to fasten two pieces of metal together
Safety precautions - Hearing protection, correct bucking bar and let people around know
Direct Riveting:
Bucking bar against manufactured rivet head, impact applied to shank of rivet.
Indirect Riveting:
Bucking bar held against shank of rivet and gun is on rivet manufactured head
Most widely used
Impact is applied to the manufactured rivet head,
Advantage: First impact drives in the rivet and ensures flush on surface structure. eliminates gapped rivet head - bad for joint
Disadvantage: Heavy structures, not always possible.
method requires structures and rivet to be moved to he bucking bar.
bad riveting efficiency - energy loss to structure. Only 1/3 impact energy to rivet
To avoid cold working and ensuing brittleness, few but powerful impacts are required
Indirect requires more powerful riveting tools.
(Bucking Bar) - smooth face not allowed to nick or scar as could lead to rivet failure
How would you carry out a Dye penetrant Test
Quick reliable test method - detecting defects - too small visual check
Capillary attraction
Penetrating liquid - low viscosity - low surface tension
30 mins excess penetrating liquid washed away with water - covered developer liquid
Reverse of capillary attraction - penetrating liquid drawn to surface and show as discouloration on developer liquid
2 types of indications
Fluorescent indication - UV light -green lines
Coloured dye indication - red lines on white surface of developer liquid
3 main principles:
1; Clean
- Time
- Remove excess liquid but not in cracks
What systems can be put in place to control tools?
Left on aircraft
Shadow boarding - traced
tool or tools are missing - what tool
quick scan - more effective
Buy their own tools
tools in a store
Look after own tools rather than company’s tools
sign their name for each and every tool that they take out
Pinpoint + what plane
Plane won’t be released - money + your job
Uncalibrated
time and cycles
recalibrated every couple of months
within calibration dates - special meters store
report a faulty tool - could endager safety of a/c#
Proved effective + greatly improved safety worlwide
What precautions should be taken when dealing with a chemical spill on the hanger floor.
Wide range chemicals - grease, oil, detergents, fillers, jointing compounds, cleaning agents, anti corrosive agents, paint, pain strippers, fuels, fuel additives, hydraulic fluids, anti-ice fluids, powders, toilet contents.
Harmles- dermatitis
Dangerous - battery electrolyte and paint stripper
Precautions - Contact barrier cream / gloves, PPE for body and eyes
Read safety notices on can /MSDS
Toxic ventilate area, sign +evacuate
wipe off any in contact + water
flammbale - ignition sources controlled + ventilate
Dispose appropriately - report, investigation + prevention
Explain the importance of keeping tools calibrated and maintained.
Values used in measurements - certain standard
Tools required accuracy - actual accuracy
Improperly calibrated tools and measurement devices don’t do as expected. - click type torque wrench - spring - out of spec - less torque per turn - nuts not as tight as speficied.
Innacurate calibration can compromise aircraft performance, component life and aircraft safety.
Machine or tool compared against another macnine whose values alraedy standardised/established/
Miscalibration - adjusting variables shouldnt be adjusted - torque
Overcalibration - adjusts variable rather than adjusting correct value then compensates by adjusting other variables for initial wrong value
EASA require part 145 part M subpart 5 maintance prganisations to idenify and specify calibration period for tools
Describe the process of changing a gas cylinder
Eligible - PPE
Replacement gas cylinder - pressure still in there - close valve brass spanner - clockwise - tied to wall
Valve fully closed, remove attachments then chains
Trasnsport to store with trolley future refilling - label it
Replacement cylinder correct stripes and labels
station apply chains
Apply attachements and open brass spanner CCW
oily/greasy rag/cloth
Test - no leaks
Describe the correct process to use a torque spanner.
Calibration date - once year - dropped/damaged
MM - torque values - ATA Chpt 20 torque procedure
nut/bolt threads clean and dry - lubricate threads nut and stud - spot face of nut being tightened - approved lubricant
Unlock knurled handle - locking knob ccw
set required torque - lock handle - locking knob cw
Install proper socket and attachment
torque nut and not bolt - reduce wear
smooth even pull - feel or hear wrench click
dont exceed max torque - hole/nut castellations dont align - change nut or washer - dont lube gasket faces or unapproved lubricant
slacken tension in spring of torque wrench - tool store job/task card - torque value - serial number of wrench and in accordance with what ATA chapter 0 certify work
Describe the safety precautions when towing or taxiing an aircraft
Weather - wind and direction - PPE - High vis vest - boots - ear muffs - gloves. - radio communication - man aircraft brakes - wing men - tail man - correct amount of men - wing men essential - hit anything - brake person - qualified driver
tyres inspected thoroughly - MM where and where not to push - never pull by propeller.
Serviceable - tech log defect entries - tow bar - tow tractor - remove locking pins - shear pins
clearnace ATC - steady pace - no jerking
end taxiing - pull until straight line - remove prolonged stresses on lower fuselage
aircraft parked - parking brake - wheels chocked - replace locking pins - engine/pitot covers if there long
What actions would you take if the pilot reports a lightning strike.
Chapter 5 AMM - Scheduled and unscheduled inspections
Pilot - tech log entry - strike occurred - symptoms - Mandatory Occurence Report - IAA + Air Accident Investifation Unit
Lightning strike 2 ways - presence aircraft strong electric field + naturally occuring discharge path
GVI - entry and exit points - pits, burns marks, discoloured skin, small circular holes, discoloured paint, punctured or delaminated skin piles, signs of arcing and burning.
most likely areas - nose radome, wing tips, tips of tailplane and fin, elevators, ailerons, rudder, landing gear, static discharges.
Necessary repairs SRM
Residual magnetism - Compass swing
avionic checks - HF - VHF Comms, transponders and ACARS
clear defect in tech log, enter in log book, certify + release
