Aviation Maintenance: Torque Wrench Operations

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What is the primary function of the spring-loaded pin in a Deflecting-Beam Dual Indication Type Wrench?

To load the spring before use

To provide a visual indication of the torque value

To prevent further tightening of the fastener

To release all force when the preset torque is reached (correct)

What is the main difference between a Break-Over Type Wrench and a Deflecting-Beam Dual Indication Type Wrench?

The Deflecting-Beam Dual Indication Type Wrench 'breaks' to prevent further tightening

The Deflecting-Beam Dual Indication Type Wrench uses a torsion beam

The Break-Over Type Wrench provides a dual signal

The Break-Over Type Wrench uses a spring-loaded ratchet device (correct)

What is the purpose of the 'click' sound in a Deflecting-Beam Dual Indication Type Wrench?

To provide a visual indication of the torque value

To load the spring before use

To alert the user when the preset torque is reached (correct)

To release all force when the preset torque is reached

What type of torque wrench is typically used for smaller sizes of nuts and bolts?

Screwdriver Type Wrench Signup and view all the answers

What is the principle behind the operation of a Torsion Bar Torque Wrench?

Torsion beam Signup and view all the answers

What is the consequence of continuing to tighten a fastener beyond the break point of a Break-Over Type Wrench?

The fastener will be over-tightened Signup and view all the answers

What is a critical aspect of the dial mechanism in a torque wrench?

It is sensitive to the twist of the square drive as torque is applied Signup and view all the answers

What is the typical repeat frequency for recalibration of a torque wrench?

6 months Signup and view all the answers

What should you do if a torque wrench reaches its calibration due date?

Return it to the standards facility for inspection and recalibration Signup and view all the answers

Why is hand position not critical to accuracy in this type of torque wrench?

Because the dial mechanism is sensitive to the twist of the square drive Signup and view all the answers

What is the purpose of the calibration date label on a torque wrench?

To indicate the calibration date and the facility that certified it Signup and view all the answers

What should you check before using a torque wrench?

Damage, calibration date label, and current calibration date Signup and view all the answers

What is the correct method to check the accuracy of a torque wrench using a spring balance?

Attach the spring balance at the centre point of the wrench handle and apply the force tangentially to the arc of movement. Signup and view all the answers

What can affect the preload applied by torque loading?

Both cleanliness and condition of the threads and type of lubrication used Signup and view all the answers

Why can other methods of applying preload be more accurate than torque loading?

They are less affected by variations in thread friction. Signup and view all the answers

What is the purpose of the nut rotation method?

To tighten the nut until it is snug and then turn it a further amount Signup and view all the answers

What is measured in the bolt-stretch method?

The length of the bolt before and after torque is applied Signup and view all the answers

What is the purpose of preload indicating washers?

To indicate the preload value Signup and view all the answers

What is the critical orientation of the instrument when measuring with an internal micrometer?

Perpendicular to the faces Signup and view all the answers

When taking a reading with an internal micrometer, what additional length must be considered?

The length of the collar and extension rod, if fitted Signup and view all the answers

How can the accuracy of an internal micrometer be checked?

By setting it to a given measurement and measuring with an external micrometer or vernier caliper Signup and view all the answers

What is the special feature of the scale on a micrometer depth gauge?

It is read from right to left Signup and view all the answers

What is the direction of the thimble divisions on a micrometer depth gauge?

The opposite direction to an ordinary micrometer Signup and view all the answers

What is the composition of the base of a micrometer depth gauge?

A hardened, ground, and lapped material Signup and view all the answers

What is the purpose of the knurled nut in a micrometer?

To hold the measuring rod in place Signup and view all the answers

How often do the rods protrude through the base of a micrometer?

Always, as they are fixed in place Signup and view all the answers

What is the significance of the 1-in movement of the screw in a micrometer?

It is the increment of measurement for each rod Signup and view all the answers

Why must micrometers with extension pieces or rods be treated as a matched set?

Because they are calibrated together for accuracy Signup and view all the answers

What is the benefit of having graduations on both sides of the datum line on some bore micrometers?

It enables more accurate readings to be taken Signup and view all the answers

What is the smallest unit of measurement possible with the bore micrometer shown?

0.0002 in Signup and view all the answers

What is the purpose of a locking nut on a feeler gauge?

To lock the blades in the desired position Signup and view all the answers

What is the unit of measurement for a standard imperial outside micrometer?

Inches Signup and view all the answers

How often are micrometers available in steps of?

1 in. Signup and view all the answers

What is the maximum distance that can be measured by a specialist micrometer?

6 ft. Signup and view all the answers

What is the benefit of a vernier scale on a micrometer barrel?

It increases the accuracy of the measurement Signup and view all the answers

What is the equivalent measurement of a metric micrometer that measures from 0 to 1 in.?

0 to 25 mm Signup and view all the answers

What is the total reading of a measurement on a standard English micrometer?

0.286 in. Signup and view all the answers

What is the purpose of the vernier scale on the sleeve of a micrometer?

To enable measurements to be made to an accuracy of tenths of a thousandth of an inch Signup and view all the answers

What is the measurement of each minor division on a micrometer?

0.025 in. Signup and view all the answers

What is the standard range of micrometers?

0-1 in. to 7-8 in. in steps of 1 in. Signup and view all the answers

When using a micrometer other than the 0-1 in. range, what must be added to the reading on the scale?

The gap in the frame Signup and view all the answers

What is the process of reading a measurement on a vernier micrometer when the datum line of the sleeve falls between the graduations on the thimble?

Using the vernier scale on the sleeve Signup and view all the answers

What is the recommended surface condition of parts during torque loading?

Clean and dry Signup and view all the answers

Why is it important to apply torque to the nut rather than the bolt head?

To ensure a direct measurement of the torque applied to the threads Signup and view all the answers

What is the correct procedure when assembling new components that require high torque loadings?

Clean and lubricate the threads and mating surfaces, then tighten to half the specified torque value Signup and view all the answers

What should you do when tightening a fastener from the bolt or screw side?

Approach the high side of the specified torque range Signup and view all the answers

What should you do when securing a torque-loaded fastener with a split pin or lockwire?

Tighten to the low side of the torque range Signup and view all the answers

What is the recommended technique when using a torque wrench?

Apply slow and steady movements Signup and view all the answers

What is the primary reason for applying a torque load to a bolt that is greater than the in-service tensile load?

To prevent relative movement between the mating surfaces and ensure the bolt doesn't come loose Signup and view all the answers

What is the consequence of under-tightening screw fasteners?

Lack of rigidity between the separate parts of the assembly, causing fretting corrosion and early failure Signup and view all the answers

What is the purpose of torque load values specified in the Aircraft Maintenance Manual?

To specify the standard torque load values for steel fasteners used in tension applications on aircraft Signup and view all the answers

What is the result of over-tightening a screw fastener?

Immediate failure of the bolts or distortion of one or more parts of the assembly Signup and view all the answers

What factors determine the torque load values for a threaded fastener?

All of the above Signup and view all the answers

What is the purpose of applying a preload to a bolt?

To prevent relative movement between the mating surfaces Signup and view all the answers

What is the purpose of the adjusting screw in vernier calipers?

To allow the sliding jaw to be finely adjusted Signup and view all the answers

What is the principle of the vernier scale?

A line of known length is divided into a certain number of divisions Signup and view all the answers

What does each division of the vernier scale represent?

A proportion of the corresponding division on the main scale Signup and view all the answers

What is the function of the line on the vernier scale that is aligned with one of the bar scale marks?

It indicates the number of thousandths of an inch to add to the measurement Signup and view all the answers

What is the purpose of the vernier scale in a slide caliper?

To increase the precision of the measurement Signup and view all the answers

What is the relationship between the number of divisions on the vernier scale and the number of divisions on the main scale?

The vernier scale has one less division than the main scale Signup and view all the answers