ACARS
An air/ground communications system used to collect data about the aircraft’s technical parameters, among others, for analysis.

Aircraft Maintenance
A generic term that embraces the full spectrum of inspection, overhaul, repair and modification operations carried out on aircraft or on aircraft components.

Airframe
Designates the structure of an aircraft, i.e., the fuselage, wings, tail section and flight controls.

AOG Desk
A dedicated logistics tracking service at Paris Charles-de-Gaulle. Its job its to supply all aircraft in an AOG (“aircraft on ground”) situation with components and services in the shortest possible timeframe, ie, in emergency situations where aircraft are grounded due to technical failures.

APU (auxiliary power unit)
Often housed in the tail section of the aircraft, the APU is like a small engine. It is mainly used on the ground to supply the electrical and pneumatic energy the aircraft needs to power its vital circuits when its main engines are shut down on the ground. If necessary, it can also be used in flight.

Associated Kit
The set of parts needed to carry out an aircraft modification.

ATEC (automatic test equipment computerized)
An automated test bench for avionics components. ATEC test benches are equipped with powerful computers running dedicated algorithms.

Aviation Authority
The official body formed by a country to oversee airlines (DGAC in France, FAA in the United States, EASA
 in Europe).

Aviation Certification
Authorizations delivered by a country’s aviation authorities. Certification is mandatory for any company wishing to offer aircraft maintenance services.

Bay
A location for an aircraft inside a hangar where maintenance work can be carried out. A hangar may, for example, be said to comprise six narrow-body bays or three wide-body bays.

BRNAV (basic radio navigation)
A system used to improve route accuracy for an aircraft’s lateral navigation.

Cabin
The term designating the area for crew and passengers on an aircraft. The term covers seating, galleys, rest-rooms and the IFE. Passenger comfort and pleasure during a flight depends largely on the quality of cabin fittings.

Close loop
In the component repair context, the repairing entity returns the part repaired to the customer, ie, the part with the same part (PN) and serial (SN) numbers.

Components
The elements that comprise the hydraulic, mechanical, electrical and electronic circuits that are essential to aircraft operation.

Engineering
Any activities designed to apply a maintenance schedule and to ascertain that the aircraft in a fleet are operating satisfactorily.

Engines
Systems used to power an aircraft. On civilian transport aircraft in the Air France fleet, these are jet engines.

Flight-hour package
A component or an engine is lent to a customer, which sends in its own component or engine for overhaul and/or repair. Once the repairs have been carried out, the exchange is reversed. This is a case-by-case service.

Galley
The area where all food is stored and prepared for in-flight catering. Its main components are foodstuff storage carts, tableware, ovens and refrigerators.

GPWS (ground proximity warning system)
An onboard warning system and decision-making aid linked to the aircraft’s position in relation to the ground.

Groupement de Surveillance Générale de l'Aviation Civile (GSAC)
A body empowered by the DGAC French civil aviation authority to oversee aircraft maintenance companies and bodies.

Heavy maintenance
Covers the airframe and selected aircraft components.
There are three types of check: the “C” or heavy check, the IL (intermediate layover) check, and the D-check.
The IL overhaul takes place between the C and D checks.
The D-check is the most detailed, and takes place every six to ten years, depending on aircraft type.

HFDL (high frequency data link)
A system used for long-distance microwave communications.

IFE (In Flight Entertainment)
Electronic systems for passengers. Includes video and audio equipment and telephone links. The most recent cabin layouts often include interactive components in their IFEs.

Inertial Navigation Unit
A computer that tells the aircraft where it is in relation to the Earth’s surface in three dimensions, with no external radio or satellite assistance.

Inspections
Technical checks carried out on aircraft, engines or aircraft components to ascertain their state. They are carried out according to a specific method and may be repetitive.
NB: a specific method means a visual check, non-destructive testing of the eddy current or FPI type, endoscopies, gamma-ray inspection, etc.

Light maintenance
Concerns the whole of the aircraft. There are three categories and the check cycles are calculated according to different modes (A, B or C checks).
- the A check is calculated in flight hours
- the C check is calculated in calendar months (eg, 18 months)

Line maintenance
There are three types of line maintenance. It is carried out at stations or at the maintenance base and concerns the entire aircraft.
- transit check after each flight,
- daily check (D), every 24 hours,
- weekly check (W).

LRU (Line Replaceable Unit)
A component that can be changed without the need for heavy industrial tools. Components of this type include aircraft black boxes or inertial navigation units.

Maintenance Manual
A manual specific to each aircraft type that describes the inspection and maintenance operations needed to maintain the capacity of an aircraft to be operated by an airline.

Maintenance Schedule
The set of operations defined by the manufacturer. The manufacturer specifies what should be inspected, how it should be done, and how often.

Maintenance Organization Exposition (MOE)
A written undertaking made by EgyptAir M&E  Industries to the aviation authorities to carry out aircraft maintenance under their supervision.

Nacelle
The structure that contains the engine and thrust reverser. On most Airbus and Boeing aircraft models, the nacelle is slung under the wing.

OEM (Original Equipment Manufacturer)
The suppliers of components mounted on aircraft. They manufacture aircraft parts but do not build the aircraft themselves.

Picking
The act of collecting a part in a warehouse following the issue of an exit note by the information system.

PMA (Parts Manufacturer Approved)
Suppliers approved by OEMs to manufacture and sell basic components such as turbine blades or hydraulic tubing.

PN (Part Number)
A number defining the identity of a component. Two components with the same PN are interchangeable.

POOL
The inventory of components used to supply spare parts to an aircraft fleet. Under a “pool” contract, the customer can obtain spare parts from the pool, ie, a component with the same Part Number (PN) but with a different Serial Number (SN).

RVSM (reduce vertical separation minimum)
A system used to improve air traffic route safety with respect to an aircraft’s movements in the vertical plane.

SATCOM
Satellite telecommunications.

Service Bulletin
A document issued by an OEM for the users of a component recommending modifications prior to technical enhancements.

Servo-control
A hydraulic actuator used to move a component that requires the application of considerable power, such as an undercarriage assembly, flaps or flight controls.

SITA
A ground/ground communication system using a network protocol

SN (Serial Number)
A number used for an individual component belonging to a family of Part Numbers (PN). The SN is a unique number and can be used for individual monitoring of all parts mounted on an aircraft.

TAT (Turn Around Time)
The time needed to carry out maintenance on a component, and engine or a complete aircraft.

TCAS
Traffic Alert Collision Avoidance System

Technical Inspections
The examination of an aircraft, a component or an aircraft circuit to check compliance with a standard established by an aviation authority.

Thrust Reversers
A system housed in the nacelles that helps to brake the aircraft during the first landing phase, just after touchdown. It reverses the thrust of the jet engines, directing the airstream forward to cause the aircraft to decelerate.

Under-Carriage
Used by an aircraft when taxiing and taking off. The undercarriage is also used to brake the aircraft on landing. In conjunction with the tyres, it also acts as a shock absorber and provides runway adherence.