Supplied B1 Module 07A textbook: PDF pages 37–44.
Care and storage of tools
Inspect tools before use for corrosion, cracked handles, damaged tips and worn working surfaces. Clean them after exposure to contaminants and apply the specified protection. Store precision equipment in its case away from shock, moisture and heat. Lubricate moving mechanisms as instructed, but avoid contaminating abrasive wheels or measuring faces. Use the tool for its intended job; a screwdriver used as a pry bar can injure the user and damage the tool. Report defects rather than returning an unsafe tool to the rack.
What should happen to a damaged tool? Remove it from service and report it.
Tool control and FOD
A tool-control system establishes what was issued, who has it and whether it was returned. Shadow boards, marked storage positions and issue records make missing tools visible. Account for tools before access panels are closed and before the aircraft is released. A missing tool requires the organisation's search and escalation process. The risk is not limited to engine ingestion: a tool can jam controls, short a circuit or damage a pipe. Personal tools need the same accountability as organisation-owned tools.
Why are tools accounted for before closing an aircraft panel? A retained tool can create a hidden aircraft hazard.
Workshop materials and segregation
Verify the specification, batch identity, shelf life and storage condition of adhesives, sealants, lubricants and cleaning agents. Similar appearance does not establish interchangeability. Separate serviceable, unserviceable and quarantined items so they cannot be accidentally issued. Record opening dates or exposure time when required. Prevent cross-contamination of oxygen-clean, composite and general workshop equipment. The correct material used after its usable life or stored incorrectly may still produce an unacceptable result.
Which check is necessary before using a controlled sealant? Specification, shelf life and storage condition.
Dimensions, allowances and tolerances
The nominal dimension identifies the intended basic size. Limits state the largest and smallest acceptable dimensions; tolerance is their difference. An allowance is an intentional dimensional difference between mating parts at a defined fit condition, not the same thing as manufacturing tolerance. If a diameter is specified as 20.00 plus or minus 0.03 mm, its limits are 19.97 and 20.03 mm and its total tolerance is 0.06 mm. Use the drawing's units and do not round away a limit violation.
What is the total tolerance of 20.00 ± 0.03 mm? 0.06 mm.
Workmanship and independent checks
Workmanship includes correct preparation, surface finish, protection and freedom from damage as well as final size. Burrs, tool marks and contamination can create stress concentrations or interfere with assembly. Follow the drawing and maintenance task rather than an informal shop convention. Required independent inspections or error-capturing checks address the consequences of an assembly error. A second signature is meaningful only when the specified check has actually been performed by a person entitled to perform it.
What does dimensional compliance alone fail to establish? That surface condition and assembly workmanship are acceptable.
Calibration and traceability
Calibration compares an instrument with a reference of known accuracy under specified conditions. It may establish corrections or identify an out-of-tolerance condition; adjustment is a separate action. Check identity, calibration status, range, resolution and suitability before measurement. Traceability connects results to recognised standards through documented comparisons. If an instrument is overdue, damaged or found inaccurate, withdraw it and assess earlier measurements as the organisation requires. A calibration label does not protect against damage after calibration.
What does calibration principally establish? The relationship between an instrument's indication and a reference.
Apply the knowledge
Work through these examples before starting the quiz. Explain why the other choices would not meet the requirement.
A tool is missing at panel close-up. What is the correct response?
Apply the missing-tool procedure before closure and release — Tool accountability must be resolved through the approved process.
A gauge was dropped yesterday but its calibration date is valid. What should happen?
Withdraw it for assessment before relying on measurements — Physical damage can invalidate a previously satisfactory calibration.
A size must lie between 9.96 and 10.02 mm. What is its tolerance?
0.06 mm — Tolerance is the upper limit minus the lower limit.
A sealant meets the specification but is past its expiry date. What is appropriate?
Do not use it unless an authorised extension process permits it — Specification and usable life are separate acceptance conditions.