7.3 Tools Flashcards
Why is accurate measurement essential in aviation engineering?
It ensures precision and safety in engineering practices
Accurate measurements are critical for ensuring that all components function correctly and meet safety standards.
What must be done before using any precision measuring tool?
Ensure it is within its calibration period
Tools must be calibrated by an approved person or organization.
What does it mean for a tool to ‘zero’ correctly?
The reading on the instrument should read zero when measuring faces are closed
If zero is not achieved, the tool requires recalibrating.
Why is calibration essential for torque wrenches?
It maintains accuracy and longevity
Calibration ensures compliance with stipulated standards for reliable measurements.
What can general wear and tear do to torque wrenches?
It can lead to incorrect and unreliable readings
Regular calibration helps mitigate these effects.
What is the purpose of a torque analyser?
To check and calibrate all types of torque wrenches and power tools
It conforms to torque tool standards ISO 6789, BS 6703, and ANSI/ASME B 107.14M.
What units of measurement can a torque analyser display?
- N.m
- dN.m
- cN.m
- lbf.ft
- lbf.in
- ozf.in
- kgf.m
- kgf.cm
- gf.cm
The unit can be selected according to the operator’s requirements.
Who performs the calibration of torque wrenches and other measuring equipment?
Approved organizations employing certified personnel
Ensures that calibration adheres to industry standards.
How are pressure gauges and transmitters calibrated?
By hydraulic pumps using water or oil, or pressure generators using oil or gas
This method ensures accurate pressure readings.
What is the process to recalibrate a micrometer?
Insert a precision block between the anvil and spindle, then align the longitudinal line with the zero mark
A special wrench is used to rotate the sleeve for calibration.
What environmental factor can affect the calibration of a micrometer?
Extreme temperatures
Temperature fluctuations can impact the accuracy of the calibration process.
What is the basic function of a screw?
A machined bolt with a thread cut into it that allows various types of screwdriver to turn the screw and apply torque.
What are the main parts of a screwdriver?
- Tip/Blade
- Shank
- Handle
What material is commonly used for the shank of a screwdriver?
Carbon steel
What is the purpose of the handle of a screwdriver?
To fit the hand and provide a non-conductive material for safety.
What are the two main classifications of screwdrivers?
- By type of tip
- By socket type arrangement
What are socket drive screwdrivers used for?
To accept multiple screwdriver bits for greater efficiency.
Name three types of specialized screwdrivers.
- Long reach screwdrivers
- Insulated (Safety) screwdrivers
- Watchmakers screwdrivers
What is a slotted screwdriver used for?
Only where slotted head screws or fasteners are found.
What is the point angle of a Phillips screwdriver?
30°
Fill in the blank: Phillips screwdrivers are sized by a number with the smaller heads corresponding to the _______.
smaller number
What distinguishes the Reed & Prince (Frearson) screwdriver from the Phillips screwdriver?
It has a pointed end and a larger angle in the V shape of 45°.
True or False: The Posidriv screwdriver is an improved version of the Phillips screwdriver.
True
What is the naming convention for Torx screwdriver bits?
Indicated by the letter T, ranging from T1 to T100.
What type of screws do internal hex (Allen Key) screwdriver bits install?
Internal hex screws
What is the size range for Tri-wing screwdriver bits?
0 to 15
What is a characteristic of Torq-set screwdriver bits?
The cross is offset.
What is the advantage of the MorTorq screwdriver bit?
It provides full contact and allows for high torque application.
What type of fastener is Hi-Torque used for?
Thin aircraft skins with a flush fitting fastener.
What tool is used to remove tightly fastened screws or damaged screw heads?
Screw extractor
Fill in the blank: The screwdriver tip must fill at least _______ of the screw slot to prevent slipping.
75%
What must be done if a screw head has cam-out damage?
Do not attempt to install; get a new screw.
What are some common applications for Phillips screwdrivers in aircraft work?
- Access panels
- Floor boards
- Interior trim
What is the main advantage of using Torx screws?
Reduced risk of cam-out and requires less operator effort.
What sizes are Mortorq screwdriver bits?
PMT-000 to PMT-8 (#0 to 1” Ø fasteners)
What is the primary function of a screw extractor?
To apply much more force to remove a screw.
What is the most common hammer type that should not be used in the aircraft engineer’s toolkit?
Carpenters or claw hammer
What are the three power sources for hammers mentioned?
- Hand powered
- Pneumatically powered
- Electrically powered
How are hammers classified?
- Pein
- Face
- Weight
- Shape
What materials are typically used for the head of a hammer?
Steel
What materials are used for the handle of a hammer?
- Wood
- Plastics
- Composite materials
What is the purpose of shock-absorbing polymers on hammer handles?
Reduce fatigue on the operator and increase comfort during use
What determines the type of hammer?
The pein of the hammer
What type of steel are Ball Pein hammers made from?
High-grade drop forged steel, fully heat-treated
What are the common uses for Ball Pein hammers?
- Use with cold chisels
- Punches
- Rivets
- Shaping of metal
What does DIN stand for in DIN hammers?
Deutsches Institut Für Normung (German Institute of Standardisation)
What is the primary function of a Soft Face Mallet?
Offer driving force without damaging surfaces
What materials are used for the faces of soft-faced mallets?
- Plastics
- Nylon
- Natural rubber
What is a key characteristic of a rubber mallet?
Heavier than other mallets, used to drive larger fasteners
What types of hammers are considered less common in aviation?
- Dead Blow hammers
- Copper hammers
- Rawhide hammers
- Sheet metal hammers
What should be checked before using a hammer?
- Handle is secured properly
- Face or pein are clean and free from burrs
What personal protective equipment (PPE) should be worn when using a hammer?
- Eye goggles
- Gloves if required
When striking an object with a hammer, how should the arm be positioned?
In line and effectively an extension on the hammer handle
What should be done if large swings are required to drive an object?
Consider replacing the hammer with a heavier one or pressing the bolt into place
True or False: Hammers can be used interchangeably without regard for the specific task.
False
What are pliers?
Pliers are a group of tools with a pair of handles joined by a fulcrum/pivot, used for gripping, bending, cutting, and twisting.
What materials should high-quality pliers be made of?
High-quality pliers should be made of alloy steel with induction hardened cutting edges and preferably have handles sheathed in soft plastic or rubber.
What are the four types of joints found in pliers?
The four types of joints are:
* Single Fixed Joint
* Toggle (Compound) Joint
* Lap Joint
* Slip Joint
What is the purpose of diagonal cutters or snips?
Diagonal cutters are intended for cutting wire and not for grabbing or turning objects.
How do diagonal cutters cut wire?
Diagonal cutters cut wire by indenting and wedging it apart rather than using a shearing action.
What are combination (lineman’s) pliers used for?
Combination pliers are multifunctional and can hold, cut, twist, or bend materials.
What is the main feature of long nose pliers?
Long nose pliers have long, thin jaws that allow for greater precision in detailed work with wire.
What are multi-grip or swan neck pliers designed for?
Multi-grip pliers have several curved grooves for interlocking joints, allowing for the application of significant force.
What is the function of vice-grip pliers?
Vice-grip pliers have adjustable jaws that clamp tightly when handles are squeezed, providing substantial gripping force.
True or False: The term ‘Mole Grip’ is a correct name for vice-grip pliers.
False
What are circlip pliers used for?
Circlip pliers are used for fitting and removing circlips during assembly or disassembly work.
What is the primary use of wire locking pliers?
Wire locking pliers are used for locking safety wire in multiple locations around an aircraft.
Fill in the blank: Pliers can cause damage to work due to their tip jaws being _______.
serrated
What types of vices are commonly classified for aircraft maintenance?
The three types of vices are:
* Metalworking vices
* Hand held vices
* Machine vices
What are the component parts of a metalworking vice?
The component parts include:
* Fixed jaw
* Adjustable jaw
* Screw or lever
What is the function of a hand vice?
A hand vice is designed for holding small work pieces and can be easily moved around during operations.
What is the main characteristic of ‘C’ or ‘G’ clamps?
‘C’ or ‘G’ clamps have a threaded screw, a moveable jaw, and a swivel plate to prevent damage to the material being clamped.
What is the purpose of covering work pieces with masking tape when using clamps?
Covering work pieces with masking tape protects them from marks and damage caused by clamps.
What type of pliers are used for detailed work with wire?
Long nose pliers
What is a significant feature of machine vices?
Machine vices can be easily moved and locked down to a surface for stability during operations.
What is the typical size range for clamps?
Clamps vary in size from one inch (25 mm) upward.
What type of joint do wire locking pliers typically use?
Single joint
What type of action do diagonal cutters use to cut larger gauge wire?
Compound-action
What is the UK term for ‘Wrench’?
Spanner
What is the US term for ‘Ratchet’?
Ratchet handle
What material is commonly used for the construction of spanners for strength and longevity?
Chrome-Vanadium Steel
What are the safety standards that tools should be tested to?
DIN3118 or ASME B107.110
List the classifications of spanners.
- Open-end Spanner
- Ring Spanner
- Combination Spanner
- Ratchet Handles
- Sockets
- C Spanner
- Strap Wrench
What is an Open-end Spanner designed to fit onto?
Hexagonal nut
What is the typical size range for spanners measured in AF?
3/16” to 1-1/16”
True or False: Adjustable spanners are recommended for use on aircraft.
False
What type of spanner surrounds the fastener and is useful in close quarters?
Ring Spanner
What mechanism does a Ratchet Ring Spanner use?
Allows a ring head to turn a fastener in one direction only
What does a Combination Spanner incorporate at each end?
Open-end spanner and a ring spanner
What is the primary function of a Breaker Bar?
To ‘break’ the torque when removing a fastener
What are the two formats of sockets?
- 6 point
- 12 point
What is the purpose of insulated tools?
To protect against electrical shock
What is a Fixed C-spanner used for?
To remove/install nuts with corresponding slots
Describe the Adjustable C-spanner.
A spanner with a split middle connected by a pin allowing for a greater size range
What is a C-pin Spanner designed for?
Nuts with holes for a pin to be inserted
What is the function of a Strap Wrench?
To apply load on an object using friction
Fill in the blank: The Adjustable Spanner has one fixed jaw and the other is moved by a _______.
thumbscrew
What types of drive sizes are commonly found for Ratchet Handles?
- 1/4” drive
- 3/8” drive
- 1/2” drive
What is the unique feature of a Pin Face Spanner?
Has two pins for nuts with locating holes
What type of fasteners do Bi-hex Open-end Spanners and Crow Foot Spanners secure?
Bleed nipples or pipework
What is the primary purpose of a Ratchet Handle?
To provide a means of removal and installation of fasteners
What is the primary function of a Torque Wrench?
Applies a specific torque or load to a fastener such as a bolt, nut, or screw.
According to ISO 6789, how are torque wrenches classified?
Torque wrenches are classified into two types: Type 1 (Indicating) and Type 2 (Setting).
What is Type 1 Torque Wrench?
Torque wrenches that indicate the torque to the user via a mechanical scale, dial, or electronically.
What is Type 2 Torque Wrench?
Torque wrenches that are either fixed or adjustable to a pre-set torque value, indicating once the pre-set torque is reached.
What is the tolerance for Type 1 Class A torque wrenches?
±6% for ≤10 Nm.
What distinguishes a Ratchet Click Type Torque Wrench?
It indicates that the desired set torque has been reached by a clicking sound.
Fill in the blank: Torque is a rotational or twisting force intended to ______ a fastener.
[rotate or turn]
What units express torque measurements?
- Newton Meters (Nm)
- Pounds feet (lbs-ft)
- Pounds-inch (lbs-in)
What should be done when storing torque wrenches?
- Keep them in original packaging
- Store in a clean area
- Clean before returning to the box
- Turn back to the lowest setting for adjustable wrenches
- Ensure instructions are included
True or False: A Fixed Torque Wrench can be adjusted to different torque settings.
False
What is a common use for a Fixed Screwdriver?
Used for lower value torques and for tasks that are repetitive and frequent.
What does a Ratchet Electronic Type Torque Wrench indicate when the desired torque is achieved?
Displays a Green light, sounds an audible buzzer, and vibrates.
What is the recommended working range for a mechanical torque wrench?
20-80% of its full scale.
What is the recommended working range for an electronic torque wrench?
10-100% of its full scale.
What safety equipment should be worn when using a torque wrench?
At a minimum, safety goggles should be worn.
What should be checked before using a torque wrench?
- Inspect for damage
- Check calibration label
- Ensure torque to be applied is within range
What happens when the torque has been indicated by a click on a torque wrench?
STOP IMMEDIATELY.
What is the purpose of the clicking sound in a Ratchet Click Type Torque Wrench?
Indicates that the desired set torque has been reached.
What is torque often referred to as?
Moment of force.
What should be done with an adjustable torque wrench before storing it?
Turn the adjustment back to the lowest setting.
What is the purpose of an audible signal in Type 2 torque wrenches?
To indicate when the pre-set torque has been achieved.
Fill in the blank: The Flex Bar torque wrench is now rarely seen and is susceptible to ______.
[damage]
What is the advantage of an Electronic Torque Wrench?
Provides clear indication and often includes audible signals once the desired torque is achieved.
What should be avoided when applying torque to a fastener?
Small tightening movements
Smooth arc loading is recommended.
What action should be taken immediately after the torque has been indicated by a click?
STOP IMMEDIATELY
This indicates that the desired torque has been achieved.
What is the lever arm in the context of a torque wrench?
The length from the center of the drive holding the socket to the handle
Denoted as L1 nominal length.
What effect does adding an extension to a torque wrench have?
Increases the lever arm to L2 extended length
This can increase the torque setting applied.
What is the critical concern for an Aircraft Engineer when using a torque wrench?
Avoiding over-torquing of fasteners
Over-torquing can go unnoticed and lead to failures.
When using an extension placed at 90° to the torque wrench arm, what happens to the torque value?
The torque value specified can be used without any change
The center of the fastener remains on the same plane.
What is necessary when calculating torque for extensions at angles other than 90°?
A torque calculation must be performed
This involves adjusting the torque value based on the new length.
What does T1 represent in torque calculations?
The torque specified for the fastener
This is the initial torque setting before adjustments.
What is an alternative method some manufacturers might specify for tightening?
Torque-angle tightening method
This method uses an angle for final torque instead of a torque value.
What is the role of the torque-angle tool?
To provide an angle that has to be used for final torque
This is an alternative to using a torque value.
Fill in the blank: If an extension is added to a torque wrench, the prescribed torque must be ______.
reduced
This adjustment accounts for the increased lever arm.
What is the purpose of torque calculation apps like the Norbar Torque Wrench Extension App?
To calculate torque values when extensions are used
These apps help ensure correct torque settings.
What are the common materials used to make rules/rulers?
Tempered carbon steel, satin-finished stainless steel
Rules can be rigid or flexible and usually come in standard lengths of six inches and 12 inches.
What are the standard fractional scale divisions for an inch?
- Halves (1/2)
- Quarters (1/4)
- Eighths (1/8)
- Sixteenths (1/16)
- Thirty-seconds (1/32)
- Sixty-fourths (1/64)
Each division corresponds to a specific measurement in millimeters.
What is the primary unit of measure used in aviation?
Inch
What is the purpose of a flexible steel tape?
Taking measurements up to several feet
It has a hook on one end to hold onto corners or ledges.
What is a combination set used for?
- Marking gauge
- Scribing lines at a 45° angle
- Depth gauge
- Height gauge
It includes a level and scriber and has a head that slides along the rule.
What type of square is the Engineers Square also known as?
Machinists Square
What is the size range of common Engineers Squares?
3” to 12”
Sizes are also available in metric.
What is the purpose of a scriber?
To scribe or mark lines on metal surfaces
What are dividers used for?
- Scribing arcs and circles
- Measuring between points
- Transferring dimensions
They are difficult to use accurately when legs are widely extended.
What are the two common types of callipers?
- Inside
- Outside
What do radius gauges measure?
Inside or outside radii
What is the purpose of a feeler gauge?
To check interface gaps or gaps under bolt heads or nuts
What are the types of punches commonly used by Aircraft Engineers?
- Prick Punch
- Centre Punch
- Automatic Centre Punch
- Starting (Taper) Punch
- Pin Punch
Each punch has a specific use related to marking or starting holes.
What angle is the tip of a prick punch typically ground to?
30° or 60°
How is a centre punch used?
To make indentations in metal to prevent ‘wander’ when drilling
What is the function of an automatic centre punch?
To create an indentation without the use of a hammer
What is a starting (taper) punch used for?
To start driving out a bolt or pin
What is the size range for pin punches?
0.8 mm to 9.5 mm in diameter
What type of punch is used for the removal of roll pins?
Roll Pin Punch
What materials are used for punches to prevent damage in sensitive environments?
- Beryllium-Copper
- Brass
These materials minimize the risk of damage or sparking.
What should be done to a punch that has become burred over time?
It must be ground back to its original shape
A hand-file is recommended for softer materials.
True or False: A steel rule is subject to calibration.
False
What are the common types of aviation hand snips?
Straight, curved, and hawksbill
Each type serves a different purpose in cutting.
What is the primary use of aviation snips?
Cutting straight lines and curves in sheet metal
What are the colors of aviation snips and their cutting capabilities?
- Yellow: cut straight
- Green: curve right
- Red: curve left
When using aviation snips, how far should cuts be made from the layout line?
About 0.8 mm (1/32 inch)
What is the main function of saws in metalworking?
Separating materials and producing grooves and notches
What are the different sizes of hacksaws typically found in a workshop?
- Full size hacksaw (6 to 16 inches, common 12 inches)
- Junior hacksaw
- Mini hacksaw
What materials are hacksaw blades commonly made from?
High-grade tool steel or tungsten steel
What does the tooth pitch of a hacksaw blade indicate?
The number of teeth per inch
What tooth pitches are commonly available for hacksaw blades?
- 14 teeth per inch (coarse)
- 18 teeth per inch (coarse)
- 24 teeth per inch (medium)
- 32 teeth per inch (fine)
What is the required cutting technique when using a hacksaw?
More than one tooth must be in contact with the workpiece
How should a junior hacksaw blade be positioned?
Teeth facing towards the handle
What is the cutting direction for a mini hacksaw?
Teeth facing forward
What are the steps to follow when using a hacksaw?
- Select appropriate blade
- Adjust blade tension
- Clamp workpiece
- Nick the surface
- Hold saw at an angle
- Start with light strokes
- Maintain even pressure
What is the primary function of a file in metalworking?
To shape metal by cutting and abrasion
What materials are most files made from?
High-grade carbon steels
What are the common shapes of files?
- Rectangular
- Square
- Round
- Half-Round
What distinguishes a single cut file from a double cut file?
Single cut has one row of parallel teeth; double cut has two crossing rows
What does the grade of cut on a file indicate?
The strength of cut based on the pitch of the teeth
List the common grades of cut for files.
- Bastard Cut
- Second Cut
- Smooth Cut
- Rasp Cut
What is the importance of file length in a workshop?
Length affects usability and is typically between 100-300mm
What care should be taken for files to prevent rusting?
Store in a clean dry environment and apply a light coating of oil
What should be checked on a file before use?
Handle for looseness, splits, or defects
What is a key technique for filing effectively?
Keep even pressure on the file during use
What are the three main filing techniques?
- Straight (Forward) Filing
- Cross Filing
- Draw Filing
True or False: The forward stroke of a file is the only cutting stroke.
True
Fill in the blank: Files should be cleaned using a _______.
Wire Brush File Card Cleaner
What is Straight (Forward) Filing?
A filing method used in a straight back and forth motion, aligned with the edge of the sheet metal.
What is Cross Filing?
A filing technique where the file is used at an angle across the workpiece, suited for thicker pieces of metal.
What is Draw Filing?
A method for achieving a smooth finish by moving the file sideways back and forth on the workpiece.
How should one file a rounded surface?
Start with the point of the file inclined downward at approximately a 45° angle and use a rocking chair motion.
What is the purpose of de-burring?
To remove fine slivers of metal hanging onto the edge of the material after filing.
True or False: Every cutting operation on sheet metal leaves burrs and/or slivers.
True
What can burrs and slivers cause?
Scratches and marks on parts, preventing proper fitting and causing personal injuries.
What tool should be used to remove burrs?
A de-burring tool.
Fill in the blank: The de-burring tool’s blade is aligned with the _______ of the workpiece to be de-burred.
[edge]
What is the common method for optimal results when using a de-burring tool?
Apply steady motion and light pressure while moving along the surface.
What is the primary purpose of drilling tools in aircraft engineering?
To drill holes in airframe structures
Drilling is a common operation for aircraft engineers.
What distinguishes a drill from a drill bit?
A drill is the tool that applies power, while the drill bit is the cutting tool that does the drilling
Common terminology in the workplace may blur this distinction.
What are the main types of drills commonly used in aviation?
- Hand Drills
- Pneumatic Drills
- Electric Drills
Pneumatic drills are preferred for safety reasons.
What is a Hand Brace used for in aviation?
To aid in the removal of screws by applying greater torque
Mainly used in carpentry, not aviation.
List the types of pneumatic drills mentioned.
- Pistol Grip Drill
- Straight Drill
- Right-angle Drill
- 45° Angle Drill
Variations may exist depending on task requirements.
What is a Drill Press also known as?
Pillar Drill or Bench Drill
Commonly used in workshops away from aircraft.
What is the risk associated with drill bits in the workplace?
They can cause Foreign Object Damage (FOD) if dropped or lost
Proper care and accounting for drill bits is crucial.
What are the two main types of drill bits referenced for use in aircraft maintenance?
- Twist Drills
- Countersink Tooling
These are the most commonly found types.
What is the function of the shank in a drill bit?
To fit into the drilling machine’s chuck
Shanks can be plain or tapered.
What is the purpose of flutes in a drill bit?
To allow removal of chips and cutting fluid to reach the cutting lips
Helical grooves cut in the body of the drill serve this purpose.
Define ‘margin’ as it pertains to drill bits.
The narrow surface along the flutes that keeps the drill aligned
It determines the size of the drill.
What does the point of a drill consist of?
- Cutting Edge (lips)
- Flank
- Face
- Web
- Chisel Edge
Each part plays a role in the drilling process.
What is the typical point angle for drilling Aluminium and Mild Steel?
118°
This angle is commonly used for these materials.
What are the categories of drill web thickness?
- Light
- Medium
- Heavy
Most aviation engineers use Light type drills.
What is a Split Point Twist Drill Bit designed to do?
Reduce wandering during initial contact with the material
It enhances drilling efficiency and reduces heat.
What is the function of a countersink tool?
To create a depression for fastener heads
Used to ensure fasteners sit flush with the surface.
How does a Microstop Countersink Tool improve countersinking?
Controls depth and keeps the cutter perpendicular to the work surface
It is the most efficient countersinking tool.
What is spot facing?
Cutting a flat area for a bolt head or nut on an uneven surface
It is typically done using a pillar drill.
What is the purpose of a reamer?
To finish a drilled hole to a precise size
Used after drilling for enhanced accuracy.
What is counter-boring?
When the surface is removed beyond what is required to provide a flat surface
What is the purpose of a reamer?
To finish a drilled hole to the exact size, producing a smooth finish
What are the two main types of reamers?
- Hand Reamers
- Machine (Chucking) Reamers
What materials can reamers be made from?
- Carbon tool steel
- High speed steel (HSS)
How do high speed steel reamer blades compare to carbon steel blades?
High speed steel reamer blades lose their sharpness quicker than those made of carbon steel
Why must reamer blades be handled carefully?
They are hardened to the point of being brittle and can chip
What is the function of the grooves on straight reamers?
To provide a way for chips to escape and a channel for lubricant to reach the cutting edge
What angle are the cutting edges of a reamer typically ground to?
45° ± 5°
True or False: Reamer flutes are designed to remove chips like a drill.
False
What is the function of a hand reamer’s square shank?
To fit into a tap wrench for applying pressure
What should be done to ensure the reamer is held straight during cutting?
Place it in the hole, turn slightly with the wrench, and view for alignment
What is the unique feature of tapered reamers?
The parallel part extends only a short distance
What is the advantage of using an adjustable reamer?
Can smooth bore walls of a drilled hole when precise sizing is necessary
What range of sizes do adjustable reamers typically cover?
From 6.35 mm (1⁄4 inch) to 25.4 mm (1 inch) in 0.08 mm (1⁄32 inch) increments
What is required to adjust an adjustable reamer?
A spanner and micrometer
How is a machine reamer driven?
Using a morse tapered shank fitted into a sleeve (Arbor)
What type of reamer is suited for drill presses?
Straight shank reamer
What is the difference between straight fluted reamers and spiral fluted reamers?
- Straight fluted: less expensive
- Spiral fluted: less tendency to chatter
What are the essential safety precautions when drilling?
- Use safety glasses
- Remove the chuck key
- Use drill stops
- Limit drill speed
- Use sharp drills
- Select appropriate drill motor
- Prevent hair entanglement
What is the use of a tap in threading?
To cut threads on the inside of a hole
What is a die used for?
To cut external threads on a round bar
What are the three types of taps in a hand tap set?
- Taper tap
- Plug tap
- Bottoming tap
What is the function of a taper tap?
To begin the tapping process with a tapered back for six to seven threads
What is the purpose of a bottoming tap?
To cut full threads to the bottom of a blind hole
What are the two general types of dies?
- Solid dies
- Adjustable dies
What is the function of the stock in threading?
To hold and turn a threading die when producing external threads by hand
What is the function of a pillar drill?
To rotate a drill bit and press it against a work piece to drill a hole.
What type of power tools are included in electrically driven power tools?
Pillar Drill (Drill Press), Abrasive Wheels.
What are the safety precautions for using powered tools?
- Keep tools in good working order
- Use the right tool for the job
- Examine each tool for damage before use
- Operate according to manufacturer’s instructions
- Provide and use proper PPE.
True or False: It is acceptable to use power tools in damp or explosive environments.
False.
What should be done before using an abrasive wheel?
Inspect it closely for cracks or defects.
What is a key feature of a bench-mounted pillar drill?
Usually belt driven with a three jaw chuck.
Fill in the blank: Electric tools must have a _______ or be double insulated.
three-wire cord with ground.
What is the recommended method for securing a work piece on a pillar drill?
Using a vice, clamps, or dogs.
What happens if the drill speed is too fast?
The cutting edges of the drill can dull rapidly.
What type of lubricant is recommended for mild steel when drilling?
Soluble Oil.
True or False: It is safe to carry a tool by the electrical wire.
False.
What should be done if a portable electric tool is damaged?
Remove it from use immediately and tag ‘Do Not Use.’
What is the potential hazard of using electric tools?
Electrocution.
What should be done with the drill bit during operation to prevent breakage?
Ease off pressure when the drill point feels likely to break through.
What is the function of a safety guard on a powered grinder?
To protect workers from the moving wheel surface and flying fragments.
What should be checked before starting a drilling operation?
Ensure the work piece is secured and in the correct position.
What is a common feature of a floor-mounted pillar drill?
It is bolted to the floor and can have a chuck capacity of 65 mm.
Drilling with a speed that is too slow can result in _______.
Breaking the drill bit.
What is the importance of clamping a work piece?
To prevent inaccurate work and injuries to the operator.
What should be done if an abrasive wheel sounds cracked or dead?
It must not be used.
What is the maximum RPM for drilling small diameter holes in brass?
3000 RPM.
What type of safety equipment should be worn when operating power tools?
Appropriate PPE, including safety glasses and gloves.
What is the purpose of using lubricants while drilling?
To keep the drill cool and assist swarf to escape.
What should the operator do when the drill bit is near the far side of the material?
Be prepared for the drill to snag and release pressure immediately.
What is the consequence of a shattered abrasive wheel?
It can harm any person near the grinder and result in serious injury.
What is typically mounted to a bench or floor and fitted with a grinding wheel on each end of the shaft?
A bench or pedestal grinder
The grinder is enclosed by a metal guard to prevent shattering of the abrasive wheel.
What is a key safety warning regarding the use of abrasive wheels?
An abrasive wheel can shatter when running at high speed
This can result in serious injuries or death.
What personal protective equipment (PPE) should be worn when operating a bench or pedestal grinder?
Appropriate PPE
This is essential for safety during grinding operations.
What should be done frequently to prevent overheating when grinding a centre punch?
Quench the punch frequently
This prevents softening of the metal.
What is the main advantage of pneumatic tools over electric tools in aviation maintenance?
Safety
Pneumatic tools reduce the risk of sparks that can ignite flammable materials.
What is the typical air supply pressure for pneumatic tools?
90-110 PSI
Higher pressures may also be seen in facilities.
What is a common source for the air supply to pneumatic tools?
An electrically driven air compressor
The compressor is usually located outside the facility.
What must be done regularly to maintain air supply systems for pneumatic tools?
Drain water from the air supply regulator and traps
Moisture can be harmful to the compressor and tools.
What feature allows pneumatic hand drills to control their speed?
Varying trigger pressure
This allows for slow, intermediate, or high-speed operation.
What type of drill is most commonly used for drilling aircraft sheet metal?
Hand held pneumatic drills
They provide control and adequate torque.
What are the two most often used drill motors?
- Pistol grip drills
- Straight drills
These drills are available in various sizes and capacities.
What is a unique feature of angled drills?
Designed to operate in tight or limited-access places
Available head angles include 30°, 45°, and 90°.
What is the purpose of a drill stop?
Regulates hole depth, cushions breakthrough, eliminates surface marks, and reduces drill breakage
It locks onto the drill with a set screw.
What does a drill guide do?
Keeps the drill at 90° to the skin surface
It consists of a clear plastic housing and hardened steel bushing.
What is the function of a hole finder?
Helps locate holes in a new skin when replacing old skin
It aligns the drill with existing holes in the structure.
What is a critical safety warning regarding workpieces while hand drilling?
Never hold a work piece by hand while hand drilling
This can result in serious injuries if a drill breaks.
What type of pneumatic tool is commonly used for airframe repair work?
Pneumatic rivet gun
It is available in various sizes and operates at specific air pressures.
What type of pneumatic tool uses a piston to squeeze rivets?
Rivet squeezer
It requires correct adaptors called dies.
What is the purpose of a pneumatic blind rivet puller?
Inserts blind rivets and pulls the mandrel until it shears
It uses interchangeable nose pieces for different rivet types.
What does a rivet shaver do?
Trims protruding mandrels of rivets
It ensures the head of the rivet is not damaged during the shaving process.
What are the main precision measuring tools used in aircraft maintenance?
Micrometers, Vernier Callipers, Dial indicators, Go/No-Go gauges
These tools are essential for ensuring the correct fit of fasteners and components.
What is the purpose of taking precision measurements in aircraft maintenance?
To ensure that the fit of fasteners and components is correct and to monitor in-service limits
Accurate measurements are essential when installing parts with specified dimensional tolerances.
What should be done before using any precision measuring instrument?
A check of its accuracy by zeroing the instrument
Instruments that fail to zero correctly need to be recalibrated under controlled conditions.
What are micrometers used for?
To take precise measurements of small dimensions
Micrometers are commonly used for measuring thickness and diameters.
Fill in the blank: Micrometer readings require careful _______.
handling
What is a key characteristic of Vernier Callipers?
They allow for measurements of internal and external dimensions
Vernier Callipers can also measure depths.
What is essential when taking Vernier Calliper readings?
Proper alignment and reading of the scale
Misalignment can lead to inaccurate measurements.
What is the function of a Vernier height gauge?
To measure the height of objects accurately
It is commonly used in machining and assembly processes.
What does a dial indicator measure?
Small distances or changes in position
Dial indicators are often used to check the runout of rotating parts.
True or False: Go/No-Go gauges are used to measure whether a part is within specified tolerances.
True
What is the importance of monitoring wear limits in aircraft components?
To ensure safety and proper functioning of the aircraft
Exceeding wear limits can lead to component failure.
Fill in the blank: Taking an accurate measurement is essential for _______ tolerance fits.
close
What is a micrometer used for?
To measure parts to the second decimal place in the metric system or the third place in the imperial system.
List the four types of micrometers.
- Internal (inside) micrometer
- External (outside) micrometer
- Depth micrometer
- Thread micrometer
Describe the basic structure of a micrometer.
A semi-circular frame with a cylindrical extension (barrel) at its right end and hardened anvils inside at the left end.
What is the pitch of the screw in a metric micrometer?
0.5 mm
How is measurement taken in a micrometer?
Between the face of the anvil and the end of the spindle.
What is the range of a standard metric micrometer?
25 mm
What is the pitch of the screw thread in an imperial micrometer?
40 threads per inch
How much does one revolution of the thimble advance the spindle face in an imperial micrometer?
1/40 inch or 0.025 inch
How is the reading line on the sleeve of an imperial micrometer divided?
Into 40 equal parts
What does every fourth line on the sleeve of an imperial micrometer represent?
One hundred thousandths
What is the purpose of a calibration check on a micrometer?
To verify accuracy and make necessary adjustments.
What is a gauge block used for in micrometer calibration?
To check and readjust the micrometer’s accuracy.
What is the function of an internal micrometer?
To measure the inner diameter of holes.
What does a three-point internal micrometer do?
Provides more accuracy to internal measurements of bores.
What does a depth micrometer measure?
Depth relative to the base plate.
How is the screw in a metric micrometer calibrated?
It has a pitch of 0.5 mm, opening 0.5 mm for each revolution.
How is a reading taken on a metric micrometer?
Add the number of hundredths indicated on the thimble to the millimetres and half-millimetres uncovered on the barrel.
What is the accuracy of a micrometer that can measure to 0.001 mm?
0.001 mm or 0.0001 inch
What must be checked before handling a micrometer?
Pre-use checks, calibration sticker, obvious damage, and zero setting.
Fill in the blank: The bevelled edge of the thimble in an imperial micrometer is divided into _______ equal parts.
25
True or False: The rim of the thimble on a metric micrometer is divided into 50 equal divisions.
True
What is a ratchet stop used for in micrometer operation?
To clamp the spindle against the subject without over-tightening.
What is a Vernier Caliper?
A tool used to make accurate internal, external, and depth measurements faster than a micrometer.
What are the three common types of calipers?
- Vernier Slide Caliper
- Digital Caliper
- Dial Caliper
What are the two main parts of a Vernier slide caliper?
- A fixed jaw with a measurement scale
- A moveable jaw with a Vernier scale
What does the Vernier scale allow?
It allows for more precise readings by comparing two lines of known length.
What is the accuracy of a 1/10 Vernier scale caliper?
0.1 mm
What is the accuracy of a 1/20 Vernier scale caliper?
0.05 mm
What is the accuracy of a 1/50 Vernier scale caliper?
0.02 mm
How is the main scale of the imperial Vernier caliper divided?
Divided into tenths, further subdivided by four.
What is the value of each division on the imperial Vernier scale?
0.001 inches
What is the first step in taking a Vernier caliper reading?
Count the total length indicated on the main scale.
How should you prepare a Vernier caliper before use?
Perform a zero error check.
What is the key advantage of a digital caliper?
Easy and quick to read with no risk of parallax error.
What are some disadvantages of digital calipers?
- Expensive to purchase
- Susceptible to environmental damage
- Usually require replacement if they fail
What system does a dial caliper use to indicate measurements?
A rack and pinion system.
What is a disadvantage of dial calipers?
They are more difficult to read than other types.
Fill in the blank: The fixed jaw of a Vernier caliper is located at _______.
one end of the beam.
True or False: Most Vernier calipers have an imperial scale on the upper section and a metric scale on the lower section.
True
What must be done if the zero error check is not satisfactory?
The instrument should be rejected and sent out for calibration.
What is the purpose of the fine adjuster on a Vernier caliper?
To achieve the final measurement.
How is the total reading calculated when using a Vernier caliper?
Add the main scale reading to the Vernier scale reading.
What is the primary function of a vernier height gauge?
To measure absolute height above a datum surface and differences in height between parts.
What type of surfaces is a vernier height gauge typically used on?
Surface plate or marking out table.
What feature does the vernier height gauge often include?
Dual scale with both millimetre and inch measurements.
What must be ensured for accurate measurements when using a height gauge?
The base of the height gauge, the surface table, and the workpiece must be perfectly clean.
What is used for making accurate markings on components with a height gauge?
A finger with a sharp ground edge.
What must be done with the height gauge after use?
Carefully return it to proper storage.
How can a vernier height gauge be used to measure the underside of a feature?
By reversing the finger.
What additional allowance must be added when measuring to the underside?
The height of the finger arm plus twice the height of the finger, that is X + 2Y mm.
Fill in the blank: The vernier height gauge has a vertical beam scale fixed to a _______.
[flat base]
True or False: The vernier height gauge can only measure absolute height.
False
What does DTI stand for?
Dial Test Indicator
Dial Test Indicator is a high-precision measurement tool used for alignment and surface smoothness.
What is the accuracy of a dial test indicator?
0.01 mm or 0.001”
What are the two types of Dial Test Indicators?
- Plunger DTI
- Lever DTI
What is the typical measurement range of dial indicators?
0.25 mm to 300 mm (0.015 in to 12.0 in)
What is the graduation range for dial indicators?
0.001 mm to 0.01 mm or 0.00005 in to 0.001 in
What is a common support for a Dial Test Indicator?
Magnetic stand
Other arrangements like clamps can also be used.
Describe the main components of a plunger DTI.
- Graduated dial
- Needle driven by a clockwork mechanism
- Smaller embedded clock face
- Spring-loaded plunger
What is the function of the limit indicators on a DTI?
To set specific measurement limits on the dial face.
How does a lever DTI differ from a plunger DTI in operation?
The lever DTI measures deflection by swinging in an arc rather than retracting.
What types of measurement can a lever DTI perform?
Measurements in narrow grooves and small bores.
What materials are commonly used for contact points in lever DTIs?
- Steel (alloy tool steel or HSS)
- Carbides (like tungsten carbide)
- Ruby
- Teflon or PVC
What is the first step in operating a DTI?
Mount the dial test indicator onto a stand.
What should you do after pressing the spindle extension against the surface?
Lock the indicator into place and observe the reading on the dial.
What do Go/No-go gauges help determine?
Whether parts are within specified limits.
What is the purpose of the two sets of jaws in Go/No-go gauges?
One set is slightly over size (go size) and the other is slightly under size (no-go size).
What does it mean if a part passes through both gaps of a Go/No-go gauge?
The part is undersized.
Fill in the blank: The difference in dimensions between the high size and the low size represents the _______.
acceptable tolerance for a part.
True or False: Go/No-go gauges can be adjustable or non-adjustable.
True
What is a typical application for Go/No-go gauges?
Checking control cable terminal fittings after swaging.
What is the importance of lubrication in aircraft?
Lubrication is critical to the safe operation of any aircraft and its systems
What is the term used for replenishing and checking aircraft systems?
Servicing
Where can information about servicing operations for a specific aircraft be found?
Chapter 12 of the Aircraft Maintenance Manual
What must be adhered to during aircraft servicing?
Mandatory tasks and safety instructions
What must be done with hoses from liquid and gas servicing trolleys when not in use?
They must be blanked and checked for cleanliness and serviceability
What type of fire extinguishers must be accessible during aircraft servicing?
Fire extinguishers suitable for fuel and electrical fires
What are the three categories of lubricants used on aircraft?
- Greases
- Oils
- Speciality Lubricants
What areas can the lubricants be used in?
- Airframe systems (Hydraulic, Flight Controls, Landing Gear etc.)
- Engine & Gearbox systems
What must be done to the lubrication equipment before use?
It must be kept clean and filled with clean/new lubricant
What personal protective equipment (PPE) should be worn when applying lubricants?
Protective gloves, eye protection, face masks, and body coverings
What is a Material Safety Data Sheet (MSDS)?
A document that contains safety information regarding specific lubricants
What happens if opened containers of lubricants are left out?
They should be disposed of to prevent contamination
What are the common methods of applying lubricants?
- Grease gun
- Hand application
- Brush
- Oil can
What is a grease nipple?
A one-way valve that isolates grease in the channel/line for lubrication
What type of grease fitting is most commonly used on aircraft?
Zerk grease nipples
What must be done before attaching the grease adapter to a grease nipple?
The nipple must be cleaned
What is the purpose of a pneumatic grease pump?
To allow quicker application of grease under constant pressure
What type of oils can be used in aircraft?
- General servicing oil
- Speciality lubricants
- Hydraulic oils
- Engine oils
What type of hydraulic oils are commonly used on aircraft?
- Mineral based oil
- Ester phosphate based oil
What is the method used to top up a mineral based fluid system?
Pouring directly into the reservoir
What is required to open a can for direct fill method?
A can opener
What is the common hand pump used to top up systems for oils?
Risbridger
True or False: All grease guns must be dedicated to a specific grease type.
True
Fill in the blank: The _______ is used to agitate the lubricant in an aerosol can.
pea
What must be done before applying speciality lubricants from an aerosol can?
Shake the can until the ‘pea’ can be heard moving
What is the primary function of an ammeter?
To measure electric current in amperes (A)
Smaller values of current can be measured using a milliammeter or microammeter.
What is the main purpose of a voltmeter?
To measure the voltage or potential difference between two points in an electric circuit
Voltmeters have very high resistance to minimize current flow through the voltmeter.
Define ohmmeter.
A device used to measure resistance, typically in ohms
An ohmmeter uses a small battery to create a current for measurement.
What is a digital multimeter?
An instrument that can measure multiple electrical properties, such as voltage, current, and resistance
Digital multimeters provide readings in numerical form.
What does an amp clamp meter do?
Measures current flowing through a conductor without direct connection
It uses electromagnetic principles to measure current.
What are the most important electrical measurements?
- Current
- Voltage
- Resistance
- Power
These measurements are essential for aircraft maintenance and troubleshooting.
What principle do most electrical measurements rely on?
Electromagnetism
This principle is based on the relationship between current, voltage, resistance, and power.
What is the Permanent Magnet Moving Coil (PMMC) meter?
The most widely used type of meter for measuring electrical values
It operates on the principle of a moving coil within a magnetic field.
How does the PMMC meter’s pointer deflection relate to current?
The pointer deflects an amount proportional to the current flowing through the moving coil
The stronger the magnetic field, the farther the coil moves.
What is ‘full-scale current’?
The amount of current that must flow through the meter coil to cause full-scale deflection
It is critical for determining meter sensitivity.
How is meter sensitivity defined?
The reciprocal value of the full-scale current, representing resistance needed to produce full-scale current
For example, a meter requiring 1 mA has a sensitivity of 1000 ohms per volt.
What is the role of a shunt in an ammeter?
To allow the meter to measure higher currents by bypassing most of the current
Shunts are designed to carry a large proportion of the current.
What is a multi-range ammeter?
An ammeter designed to measure multiple current ranges by using different shunt resistors
Users can select the desired range via a switch.
Describe a DC voltmeter’s connection in a circuit.
It is connected in parallel with the load to measure voltage
The voltmeter must be connected with the correct polarity.
What is a multiplier resistor in a voltmeter?
A resistor placed in series with the meter movement to limit current for full-scale deflection
It helps in extending the measurement range of the voltmeter.
What must be done before using an ohmmeter?
Calibrate the device by shorting the test leads
Calibration ensures accurate readings for unknown resistances.
What happens to the ohmmeter’s pointer when the test leads are separated?
The pointer returns to the left side of the scale (infinity)
This indicates no current flow through the meter.
True or False: Voltmeters can be used to measure AC voltage.
False
DC voltmeters should not be used for AC voltage measurements.
What must be done to the test leads after using an ohmmeter?
Remove the test leads to prevent accidental discharge of the ohmmeter battery
This is important due to high internal current when short-circuiting.
What happens to the pointer of an ohmmeter when the test leads are separated?
The pointer will return to the left side of the scale (infinity)
This is due to the interruption of current and spring tension acting on the movable coil assembly.
How is the indication of an ohmmeter characterized compared to voltage and current meters?
The indication is ‘backwards’, with maximum indication (infinity) on the left
Voltage and current meters have zero at the left of their scales.
What position must the power switch of the circuit be in when measuring resistance with an ohmmeter?
The power switch must be in the Off position
This prevents damage to the meter movement.
In a circuit measured by an ohmmeter, what does the amount of current that flows through the meter coil depend on?
The total resistance of resistors R1 and R2 and the resistance of the meter
The meter has been pre-adjusted for zero.
What is the effect of replacing resistors R1 or R2 with larger value resistors in an ohmmeter circuit?
The current flow in the moving coil of the meter would decrease, resulting in further decreased deflection
The scale indication would read a higher circuit resistance.
True or False: Ohmmeters can be connected to an energized circuit.
False
Any voltage applied to the test leads of an ohmmeter invalidates its reading.
What is the nature of the ohmmeter scale?
The scale is very non-linear and reversed compared to voltmeters and ammeters
This is due to the current-operated nature of the meter.
What should be done to obtain the most accurate measurement of resistance using an ohmmeter?
Use a scale that results in a pointer deflection in the centre third of the dial
The scale has numbers that are widely separated at the low-range end.
What are the typical operational ranges indicated on a practical ohmmeter?
R × 1, R × 10, R × 100, R × 1 000, R × 10k, R × 100k
The reading on the ohmmeter scale is multiplied by the factor indicated by the range setting.
How does a shunt ohmmeter differ from a series ohmmeter?
In a shunt ohmmeter, the resistance to be measured is in parallel with the meter movement
In a series ohmmeter, the resistance is in series with the internal resistors.
What is a safety ohmmeter designed for?
Testing resistance in volatile and explosive devices
It uses a very small current for testing resistance.
What happens when a DC meter is connected to an AC circuit?
It indicates zero
This is because the meter movement is restricted to direct current.
What is the purpose of a rectifier in measuring AC with a moving coil meter?
To convert AC to DC
A full-wave rectifier is preferred for higher sensitivity.
What is the effective value (RMS value) used for in AC meters?
It represents the average value of the pulsating DC to which the meter is reacting
The meter movement reacts to the average value of half of the sine wave.
What is a multimeter?
A device that can function as a voltmeter, ammeter, or ohmmeter
It connects to different external resistor networks.
What is the common use of a Digital Multimeter?
For field service technicians and general purpose electronics work
It offers convenient one-handed operation and various measurement capabilities.
When connecting test leads to a circuit with a multimeter, which lead should be connected first?
Connect the Common (COM) test lead before connecting the live lead
This is important for safety.
What is a current clamp?
An electrical device that clamps around a conductor to measure current without physical contact
It operates on the principle of a current transformer.
What precautions must be taken when using electrical measuring instruments?
Use a meter that meets safety standards, check calibration, inspect test leads, and use proper function and range
These precautions minimize the risk of electric shock and equipment damage.
