Definitions — Page 10, Lesson 10

We are starting the Definitions section of your Air Law manual. This is the glossary that underpins everything else in the course, so we will go through it methodically. I want you to get comfortable with the fact that in this industry, precision of language is a safety feature. A single letter can change the meaning of a regulation, so we treat these abbreviations with absolute respect. Let's begin with the first block. AMC stands for Acceptable Means of Compliance. This is a document published by a regulatory body that tells you a way to comply with a regulation, but it is not the only way. It is the standard method that the regulator has pre-approved. If you follow the AMC, you are presumed to be compliant. AME is the Aero Medical Examiner. This is the doctor who is specifically designated to conduct the medical examinations required for pilots and air traffic controllers. They are not just any physician; they are licensed by the aviation authority to assess your fitness to fly. AMO is the Approved Maintenance Organization. This is a company that has been certified to perform maintenance on aircraft. They hold an approval that allows them to release aircraft back into service after maintenance. AMOSS is the Airline Maintenance and Operation Support System. This is the integrated computer system that an airline uses to manage the logistics of keeping its aircraft maintained and its operations running. It tracks maintenance schedules, parts, and operational data. AMSL is Above Mean Sea Level. This is the altitude measured from the average level of the sea. When we say an aircraft is at 10,000 feet, we usually mean 10,000 feet AMSL, unless we specify otherwise. This is the standard reference for terrain clearance and flight levels. AMT is Approved Maintenance Training. This refers to the training courses that are approved by the authority for maintenance personnel. It ensures that engineers are trained to the correct standard. ANO is the Air Navigation Order. This is a legal document, in the UK context, that contains the regulations for the operation of aircraft. It is the primary law for aviation in that jurisdiction. A-NPA is the Advance Notice of Proposed Amendment. This is an early notification that a regulator is thinking about changing a rule. It is a consultation stage, giving the industry a chance to comment before a formal proposal is made. AOC is the Air Operator’s Certificate. This is the certificate that an airline must hold to operate commercial flights. It is the fundamental license for an airline. Without it, you cannot carry passengers or cargo for reward. A/P is simply Autopilot. That is the system that can control the aircraft's flight path without continuous manual input from the pilot. APO is the Approved Production Organization. This is a manufacturer that has been approved to build aircraft, engines, or propellers. They have a quality system that the authority has certified. APU is the Auxiliary Power Unit. This is a small turbine engine located in the tail of most airliners. It provides electrical power and pneumatic pressure when the main engines are off, for example, at the gate or during engine start. ARC is the Airworthiness Review Certificate. This is a certificate that confirms an aircraft remains airworthy after a review. It is part of the continuing airworthiness process, distinct from the initial Certificate of Airworthiness. ARP is the Aerodrome Reference Point. This is the designated geographical position of an aerodrome. It is used for navigation and for defining the aerodrome's location on charts. ARN is the ATS Route Network. This is the network of designated routes for air traffic services. These are the "highways in the sky" that aircraft follow under air traffic control. ASDA is the Accelerate-Stop Distance Available. This is the length of runway available for an aircraft to accelerate to a decision speed and then, if necessary, stop safely. It is a critical performance calculation for take-off. ASL is Above Sea Level. This is a more general term than AMSL, simply meaning the height above the sea. It is often used interchangeably, but AMSL is the more precise technical term. ASR is the Altimeter Setting Region. This is a defined area within which the same altimeter setting is used. This ensures that all aircraft in that region are measuring their altitude from the same reference, preventing collisions. ATAS is the Air Traffic Advisory Service. This is a service provided to aircraft in airspace where there is no full air traffic control, but where advice is given to help pilots avoid collisions. ATC is Air Traffic Control. This is the ground-based service that directs aircraft on the ground and in the air, issuing instructions to ensure safe separation. ATCC is the Air Traffic Control Centre. This is the large facility that controls aircraft in a wide area of airspace, typically en-route. ATCU is the Air Traffic Control Unit. This is a more general term for any unit that provides air traffic control, which could be a tower or an approach unit. ATCRU is the Air Traffic Control Radar Unit. This is a specific unit that uses radar to provide control. ATFM is Air Traffic Flow Management. This is the system that manages the flow of traffic to prevent overload of the ATC system. It is what causes ground delays when there is congestion. ATIS is the Automatic Terminal Information Service. This is a continuous broadcast of recorded information at an airport, such as weather, runway in use, and NOTAMs. Pilots listen to this before contacting the tower. ATM is Air Traffic Management. This is the overarching term that includes ATC, ATFM, and all the other services that manage air traffic. ATO is the Approved Training Organization. This is a training school that has been approved to provide pilot or maintenance training. Your own training provider would hold this approval. ATS is Air Traffic Service. This is the generic term for all the services provided to aircraft, including ATC, advisory services, and flight information. ATSU is the Air Traffic Service Unit. This is any unit that provides an ATS, such as a control tower or a centre. ATTCS is the Automatic Take-off Thrust Control System. This is a system that automatically reduces engine thrust during take-off if an engine fails, to maintain the required climb performance. ATZ is the Air Traffic Zone. This is a defined area of airspace around an aerodrome, designed to protect traffic in the circuit. AUW is All Up Weight. This is the total weight of the aircraft, including the aircraft itself, fuel, passengers, cargo, and everything else on board. AWD is the Airworthiness Division. This is the part of the regulatory authority that deals with airworthiness matters. AWO is All Weather Operations. This refers to operations that can be conducted in low visibility conditions, such as Category III approaches. AWY is Airway. This is a specific route in the ATS Route Network, usually defined by radio beacons. Now, moving to the next block. BEA is the Bureau d’Enquêtes Accidents. This is the French accident investigation bureau, and it is the French equivalent of the NTSB. It investigates aviation accidents in France. BR is the Basic Regulation. This is the foundational European regulation that establishes the European Aviation Safety Agency, or EASA, and sets out the framework for civil aviation safety in Europe. CAA is the Civil Aviation Authority. This is the national regulatory body for civil aviation in a country, such as the UK CAA. CAME is the Continuous Airworthiness Maintenance Exposition. This is a document that describes how an organization manages the continuing airworthiness of its aircraft. It is a key document for an AMO. CANP is the Civil Aviation Notification Procedure. This is the procedure for notifying the civil aviation authority of certain events or changes. CAS is Controlled Airspace. This is airspace within which air traffic control service is provided. Aircraft must have a clearance to enter it. CAT is Commercial Air Transport. This is the operation of an aircraft to carry passengers, cargo, or mail for remuneration or hire. This is what an AOC holder does. CDFA is the Constant Descent Final Approach. This is a technique for flying a final approach at a constant angle, rather than in steps, which improves safety and reduces noise. CF is Certification. This is the process by which an aircraft or component is approved as meeting the required standards. CJAA is the Central Joint Aviation Authorities. This was the central body of the former Joint Aviation Authorities, the predecessor to EASA. C of A is the Certificate of Airworthiness. This is the certificate that states an aircraft is airworthy and fit for flight. It is the fundamental document for an aircraft. COM is the (European) Commission. This is the executive body of the European Union, which proposes legislation. CRD is the Comment Response Document. This is a document published by a regulator that responds to comments received on a proposed rule, explaining what changes were made. CRI is the Certification Review Item. This is a specific item that is identified during the certification of an aircraft that requires special attention. CRS is the Certificate of Release to Service. This is the certificate that an engineer signs to state that maintenance has been completed correctly and the aircraft is safe to fly. CS is Certification Specification. These are the technical standards that an aircraft must meet to be certified. For example, CS-25 is for large aeroplanes. CSP is the Certification Standardization Panel. This is a panel that works to standardize certification practices across different authorities. That completes the first part of the definitions. We have covered the core organizational, operational, and airworthiness terms. Take a moment to let these settle, and we will move on to the next block when you are ready.