Aviation dictionary

Federal Aviation Administration — the civil aviation authority of the United States.

The FAA issues Airworthiness Directives for aircraft registered in the United States.

European Union Aviation Safety Agency — the civil aviation authority for EU member states.

EASA published an AD adopting the manufacturer's inspection bulletin.

International Civil Aviation Organization — the UN body that sets global aviation standards.

National regulations are built on the standards in the ICAO Annexes.

Civil Aviation Authority of Israel — the national regulator for Israeli civil aviation.

The CAAI issues Type 1 and Type 2 aircraft maintenance licences.

National Aviation Authority — the regulator responsible for civil aviation in a given state.

Every operator holds an approval issued by its NAA.

The regulation that approves an organisation to perform aircraft maintenance.

The hangar operates under a Part-145 approval with an exposition and a quality system.

The regulation covering aircraft maintenance licences, categories and privileges.

A Part-66 B1 licence covers airframe, engines and mechanical systems.

The regulation covering continuing airworthiness management of an aircraft.

The CAMO manages the maintenance programme under Part-M.

The regulation approving maintenance training organisations and examinations.

The basic training course was delivered by a Part-147 approved school.

The regulation covering design and production organisations and certification of products.

A major repair design must be approved under Part-21.

Continuing Airworthiness Management Organisation — manages the airworthiness of an operator's fleet.

The CAMO tracks AD compliance and schedules the next check.

The approval confirming that an aircraft type meets the applicable design standards.

Modifications must remain within the limits of the Type Certificate.

Supplemental Type Certificate — approval for a major change to a certified product.

The new cabin interior was installed under an STC.

The document confirming an individual aircraft is airworthy and may fly.

The Certificate of Airworthiness stays valid while the aircraft is maintained to its approved programme.

Personnel authorised to sign a certificate of release to service.

Only certifying staff listed in the exposition may sign the CRS.

Aircraft Maintenance Manual — step-by-step procedures for maintaining aircraft systems.

Follow AMM task 32-41-00 to replace the brake unit.

Illustrated Parts Catalogue — exploded diagrams with part numbers and effectivity.

Use the IPC to confirm the correct bracket part number before ordering.

Structural Repair Manual — allowable damage limits and approved structural repairs.

The dent was within SRM allowable damage limits, so no repair was required.

Component Maintenance Manual — workshop testing, repair and overhaul of a removed component.

The valve was overhauled in the shop in accordance with the CMM.

Fault Isolation Manual — structured troubleshooting for reported defects.

The FIM led from the ECAM message to a single faulty sensor.

Trouble Shooting Manual — the Airbus equivalent of a fault isolation manual.

The TSM procedure isolated the fault to the wiring, not the computer.

Wiring Diagram Manual — electrical schematics, connectors and wire routing.

The WDM showed which pin to check at the connector.

System Schematic Manual — functional schematics of aircraft systems.

The SSM explained how the two hydraulic systems interact.

Minimum Equipment List — items that may be inoperative for dispatch, with conditions.

The aircraft was dispatched under MEL item 21-26 with a placard fitted.

Configuration Deviation List — secondary airframe parts that may be missing for dispatch.

A missing access panel was covered by the CDL with a performance penalty.

Maintenance Planning Document — the manufacturer's recommended maintenance tasks and intervals.

The operator built its approved programme from the MPD.

Aircraft Maintenance Programme — the approved schedule of tasks for a specific operator.

The C-check package is generated from the AMP.

A controlled work document describing one maintenance task and its sign-offs.

Each task card must be signed by the technician and the certifying staff.

The aircraft or component serial numbers to which a procedure or part applies.

Always check effectivity — the procedure may not apply to your tail number.

A controlled update to a manual, replacing superseded information.

Work only from the current revision; withdrawn pages must not be used.

An urgent manual change issued before the next full revision.

A Temporary Revision shortened the inspection interval.

Standard numbering that organises technical information by aircraft system.

ATA 27 is Flight Controls and ATA 32 is Landing Gear.

The modern ATA specification for aviation technical information.

Manual numbering follows iSpec 2200 on current aircraft types.

Technical data accepted or approved by the authority for use in maintenance.

A repair may only be carried out using approved data.

A mandatory instruction from the authority correcting an unsafe condition.

AD compliance is recorded in the aircraft records with method and date.

Abbreviation for Airworthiness Directive.

The AD required a repetitive inspection every 500 flight cycles.

A manufacturer document describing an inspection, modification or improvement.

The SB was optional until an AD made it mandatory.

Abbreviation for Service Bulletin.

SB 57-1042 introduced an improved wing fitting.

A service bulletin the manufacturer considers urgent for safety.

The ASB required action before the next flight.

Manufacturer advice or information with no mandatory action.

A Service Letter clarified the correct lubricant.

The condition of an aircraft being fit and safe for flight.

Airworthiness is maintained by approved maintenance and correct records.

All processes that keep an aircraft airworthy throughout its life.

AD tracking and defect management are continuing airworthiness activities.

A condition that could affect the safety of the aircraft if left uncorrected.

The AD was issued after cracks revealed an unsafe condition.

The approved way an AD or bulletin requirement is satisfied.

The record shows the compliance method, date and the person who certified it.

Alternative Method of Compliance — an authority-approved alternative to an AD requirement.

An AMOC allowed an extended inspection interval.

An inspection that must be repeated at a stated interval.

The repetitive inspection is due every 1,000 flight hours.

Work that ends the requirement for a repetitive inspection.

Installing the reinforced fitting was the terminating action.

A part that must be removed at a fixed life regardless of condition.

Life-limited parts are tracked by cycles and cannot be extended.

A document confirming an aircraft's airworthiness after a documented review.

The ARC is renewed after a satisfactory airworthiness review.

The signed statement that maintenance was completed to approved data.

No aircraft may fly after maintenance without a valid CRS.

Abbreviation for Certificate of Release to Service.

The CRS references the task, the data used and the date.

The onboard record of flights, defects and maintenance actions.

The crew entered the defect in the technical log after landing.

A defect allowed to remain unrectified under controlled conditions.

The defect was deferred under the MEL for three days.

Maintenance carried out between flights, mostly at the gate or ramp.

A tyre change is typical line maintenance.

Heavier maintenance performed in a hangar with the aircraft out of service.

The C-check was performed as base maintenance over ten days.

Planned tasks performed at fixed intervals.

Scheduled maintenance comes from the approved maintenance programme.

Work arising from a defect or unexpected finding.

A bird strike inspection is unscheduled maintenance.

Restoring a component to a serviceable condition defined by approved data.

The actuator was overhauled and returned with a release certificate.

A part or aircraft that meets its approved standard and may be used.

The unit was tagged serviceable with an EASA Form 1.

A part or aircraft that does not meet the approved standard.

Unserviceable parts are quarantined so they cannot be refitted.

An authorised release certificate for a component in the European system.

The pump arrived with a Form 1 confirming its serviceability.

The equivalent authorised release certificate in the United States system.

Dual release on an 8130-3 allowed use on both registries.

Documented history proving a part's origin, status and approvals.

Without traceability a part may not be installed.

An unapproved or counterfeit part presented as airworthy.

Strict traceability checks keep bogus parts out of the supply chain.

A second check by another qualified person on critical work.

Flight control rigging requires an independent inspection.

How human performance and limitations affect maintenance safety.

Human factors training addresses fatigue, pressure and communication.

Twelve common human-factor causes of maintenance error.

Lack of communication and complacency are two of the Dirty Dozen.

A reporting culture that separates honest error from wilful violation.

Just culture encourages technicians to report their own mistakes.

Maintenance Review Board — defines the initial scheduled maintenance requirements for a type.

MRB output feeds the manufacturer's planning document.

The outer covering of the aircraft, carrying aerodynamic and structural loads.

The skin panel was replaced after impact damage.

A transverse member giving the fuselage its shape and carrying hoop loads.

Cracks were found at the frame-to-stringer junction.

A lengthwise stiffener that supports the skin against buckling.

The repair spanned two stringers either side of the damage.

The main spanwise beam of a wing or stabiliser.

Spar damage always requires an engineering assessment.

A chordwise member giving the wing its aerofoil shape.

The rib supports the skin between the front and rear spar.

A heavy lengthwise structural member carrying bending loads.

The door cut-out is reinforced by longerons.

A structural partition, often pressure-carrying, across the fuselage.

The rear pressure bulkhead seals the pressurised cabin.

An added plate that reinforces structure or carries load around damage.

The repair used an external doubler with two rows of fasteners.

Construction in which skin, frames and stringers share the loads.

Most transport fuselages are semi-monocoque.

A permanent fastener installed by deforming its shank to clamp the joint.

Solid rivets were driven with a bucking bar behind the skin.

A rivet installed from one side only, where the back is inaccessible.

Blind rivets were used inside the closed box section.

Any device that joins parts — rivets, bolts, screws or specialty pins.

Fastener type and material must match the drawing exactly.

The rotational force applied to a fastener to produce the required clamping load.

Torque the nut to the AMM value using a calibrated wrench.

The clamping force retained in a fastened joint after tightening.

Correct preload prevents the joint from working loose.

The distance from a fastener centre to the edge of the material.

Too little edge distance lets the fastener tear out.

Wire installed to prevent a fastener from rotating loose.

Safety wire is fitted so any loosening tightens the wire.

An electrical connection that keeps structure at the same potential.

Bonding straps protect against lightning and static build-up.

Compound applied to seal joints against fuel, air or moisture.

Fuel tank fasteners are installed wet with sealant.

A material of fibres in a resin matrix, such as carbon or glass fibre.

Composite panels are light and do not corrode, but damage is harder to see.

Aluminium alloy with a pure aluminium surface layer for corrosion protection.

Never sand through the Alclad layer during blend-out.

A non-structural cover that smooths airflow over structure.

The belly fairing was removed for access.

A removable panel giving access to structure or systems.

Access panels must be refitted with the correct fasteners and torque.

General Visual Inspection — a broad visual check of an area for obvious defects.

A GVI of the wheel well is performed at each transit check.

Detailed Inspection — a close examination with good lighting and often special tools.

The DET required a mirror, a torch and surface cleaning.

Non-Destructive Testing — inspection that does not damage the part.

Eddy current NDT was used to check around the fastener holes.

An NDT method using electromagnetic fields to find surface and near-surface cracks.

Eddy current found a crack invisible to the naked eye.

An NDT method using sound waves to find internal defects and measure thickness.

Ultrasonic testing confirmed the remaining skin thickness after blend-out.

An NDT method revealing surface-breaking cracks with coloured or fluorescent dye.

Dye penetrant is used on non-magnetic parts.

A simple check where sound differences reveal disbonds in composite panels.

A dull sound during the tap test indicated delamination.

A depression in the surface with no material removed.

The dent was measured for depth, length and location before assessment.

A shallow surface mark with a small amount of material removed.

The scratch was polished out within SRM limits.

A deeper surface cut removing material and creating a stress raiser.

A gouge is treated more seriously than a scratch of the same length.

A separation in the material that grows under repeated loading.

Any crack in primary structure must be reported before further flight.

Deterioration of metal by chemical or electrochemical reaction with its environment.

Corrosion was found under the galley floor where moisture collects.

Corrosion where two dissimilar metals meet in the presence of moisture.

Insulating material prevents galvanic corrosion between steel and aluminium.

Corrosion that lifts metal in layers, typical of extruded sections.

Exfoliation looked like the pages of a book along the stringer.

Separation between the internal layers of a composite.

Delamination often leaves no visible mark on the surface.

Damage the SRM permits to remain, sometimes with limits or repeat checks.

The dent was within allowable damage, so only a record entry was needed.

Smoothing damage away to remove a stress raiser, within published limits.

The scratch was blended out and the area re-protected.

A feature such as a sharp notch that concentrates stress and starts cracks.

Sharp corners in a repair are avoided because they act as stress raisers.