ATA Chapters & Subsystems Lookup (iSpec 2200 Master Index)

Search the complete iSpec 2200 and ATA 100 reference index instantly by chapter number, subsystem code, or system name.

iSpec 2200 MASTER LOOKUP

The absolute, unabridged reference index mapping standard 2-digit chapters and 3-element numeric subsystem component codes under true global A4A specifications.

How to Search the iSpec 2200 Index

This lookup database maps commercial aircraft documentation standards. The index filters in real time across the entire technical manual architecture using three input methods:

Chapter Code: Enter any standard 2-digit identifier (e.g., 21 for Air Conditioning, 32 for Landing Gear).
Subsystem Code: Enter specific system subdivisions with or without dashes (e.g., typing 27-50 or 2750 instantly isolates Trailing Edge Flaps).
System Keyword: Search by component or system name (e.g., Brakes, FADEC, APU, IMA).

Search Tip: The search engine strips punctuation automatically. You can type raw numbers like 7320 to immediately display the subsystem for Engine Fuel Controls and FADEC computers.

What is the iSpec 2200 / ATA 100 Standard?

The international aviation sector utilizes a standardized system categorization managed by Airlines for America (A4A), formerly known as the Air Transport Association (ATA). Originally introduced as ATA 100, the standard evolved into iSpec 2200 to govern digital technical documentation, structural maintenance data, and parts tracking globally.

Every commercial aircraft manufacturer—including Airbus, Boeing, Bombardier, and Embraer—organizes their Aircraft Maintenance Manuals (AMM), Illustrated Parts Catalogs (IPC), and Wiring Diagram Manuals (WDM) using this precise numbering system.

The 3-Element Numbering System Explained

When a technician views a maintenance task or logbook entry, the numbering format follows a strict 6-digit structural block broken down as XX-YY-ZZ:

Chapter (First Element – XX): Specifies the major airframe or powerplant system (e.g., 28 indicates the entire Fuel System layout).
Section (Second Element – YY): Identifies a specific sub-system distribution within that chapter (e.g., 28-40 isolates Fuel Quantity Indicating).
Subject (Third Element – ZZ): Pinpoints the precise line-replaceable unit (LRU), sub-component, or electrical probe being serviced (e.g., 28-40-01).

Maintenance Manual Architecture: Systems vs. Structures

A common point of confusion for technical records clerks and junior technicians is differentiating between an operational system and its physical structure. The iSpec standard handles them under entirely distinct chapters:

The System Chapter (ATA 21 to 49): Governs operational components, wiring, actuators, valving, and control software. For example, ATA 27-50-00 covers the Trailing Edge Flap Actuator Synchronizers and hydraulic control valves.
The Structure Chapter (ATA 51 to 57): Governs physical metal or composite geometries, spars, ribs, hinges, skins, and structural patches. For example, ATA 57-53-00 covers the physical trailing edge flap composite panels, roller tracks, and structural carriages.

Always ensure you are referencing the correct operational group depending on whether you are tracking a mechanical system failure or evaluating structural skin damage.

Core Operational Groups Matrix

The iSpec 2200 specification splits technical documentation into five major system groups to ensure logical categorization from nose to tail:

Technical Group Range	Documentation Category	Operational Focus
Chapters 05 – 18	Aircraft General	Ground handling boundaries, physical aircraft dimensions, safe leveling datums, jacking adapters, and mandatory letter-check maintenance intervals.
Chapters 20 – 50	Airframe Systems	Internal mechanical and electrical configurations including environmental packs, communication buses, main AC/DC power networks, landing gear mechanics, and hydraulic loops.
Chapters 51 – 57	Airframe Structure	Pure structural metallic and composite geometries, bulkhead frames, fuselage skin patches, window assemblies, and main wing box spar internals.
Chapters 61 – 67	Propeller / Rotor Systems	Dynamic mechanical propulsion architectures, propeller hub governors, helicopter main swashplate linkages, and tail rotor driveshaft bearings.
Chapters 71 – 84	Powerplant Systems	Core engine configurations covering turbine compressor blocks, ignition systems, FADEC integration, thrust reverser actuators, and turbocharging assemblies.

High-Volume Reference Chapters Quick Lookup

For rapid reference, these are the most frequently accessed ATA chapters handled by line maintenance crews, avionics technicians, and parts procurement brokers:

ATA 05: Time Limits & Scheduled Maintenance Checks (A, B, C, D Letter intervals)
ATA 12: Servicing (Fluid replenishment, oil tracking, system greasing constants)
ATA 21: Air Conditioning and Cabin Pressurization systems (Packs, ACM, Outflow valves)
ATA 24: Electrical Power (IDG, AC generators, DC networks, TRU rectifier units)
ATA 27: Flight Controls (Ailerons, rudders, elevators, flaps, and slat actuators)
ATA 29: Hydraulic Power (Engine driven pumps, RAT deployment, reservoirs)
ATA 32: Landing Gear (Brake assemblies, shock struts, retraction actuators, anti-skid systems)
ATA 34: Navigation hardware (Air data computers, weather radar, IRS laser rings, ILS receivers)
ATA 42: Integrated Modular Avionics (IMA computing blades and shared core network architecture)
ATA 52: Airframe Doors (Passenger cabin pressure doors, emergency exits, cargo hatch latches)
ATA 73: Engine Fuel & Control (FADEC units, fuel manifolds, spray nozzle lines)

Technical Maintenance Document Applications

Standardized system coding is mandatory for cross-department synchronization inside airlines, repair stations, and parts distributors.

Aircraft Maintenance Manuals (AMM): Every inspection task, removal guide, and installation method is categorized under its specific ATA code so mechanics can locate engineering steps instantly.
Minimum Equipment Lists (MEL): If an instrument or system becomes inoperative before a flight, dispatchers check the MEL under that system’s chapter to find out if the aircraft is legally grounded or safe to fly.
Component Maintenance Manuals (CMM): Off-wing components sent to specialized workshop repair facilities are tracked, invoiced, and audited using their parent iSpec code structure.
Reliability Tracking & Logbooks: Flight crew squawks and mechanical deferrals must reference the correct system identifier to flag recurring hardware issues during fleet data audits.

Industry Note: The Transition from iSpec 2200 to S1000D

While iSpec 2200 remains the operational standard for legacy fleets and active commercial transport airframes (such as the Boeing 737NG/MAX and Airbus A320 families), newer aircraft lines utilize the S1000D specification.

S1000D is an international XML standard that breaks technical content down into relational Data Modules (DM) rather than fixed page blocks or linear chapters. However, to maintain backward compatibility and logical grouping, the structural numbering system within S1000D Data Module Codes (DMCs) still largely maps directly to the historical 2-digit ATA chapter foundations outlined in this lookup directory.