Know How ATA Chapters Helps Repairing an Aircraft

Posted on January 24, 2019 Michael Jones Aviation Standards

ATA chapters are highly valuable to aircraft repair stations. Each code is designated to a specific part of the aircraft. These codes were originally made by the Air Transport Association (ATA) in 1956; they have seen been adopted by all major airlines and OEMs. The ATA chapters are designed with 3 sets of two-digit numbers, typically in an AB-CD-EF format. The first two digits are the most important.

Full ATA chapter codes for each part is created by the individual OEM, but they must follow the standard format and traditional number designation of the first two numbers. However, beyond that nothing else is specified by any authority except the OEM. For example, ATA chapter 29 is hydraulics. So, all ATA chapter codes starting with 29 must be hydraulic parts. The remaining four can be anything, which can cause confusion because there can be overlap in ATA chapter codes from one OEM. For example, Satair has 29-10-02 for a solenoid operated 3-way hydraulic directional control valve while Sitec Aerospace has 29-10-02 listed under a 2/2-way manual bleed valve.

ATA chapters are important because major airlines will designate certain ATA chapters to repair buyers. This process allows each repair buyer to become an expert and specialize with the chapter— knowing anything and everything for that chapter, which is important for building trust and having a go-to person for all those needs. This also solves the issue of accidentally buying the wrong part number, because each repair station will be very knowledgeable of the part and any possible overlaps, streamlining the entire process.
Some examples of what an ATA chapter may consist are:

ATA chapter 25: Equipment/Furnishings: Coffee makers, water heater, crew seats, dual cavity ovens
ATA chapter 26: Fire protection: Smoke detectors, fire harness
ATA chapter 28: Fuel: Pumps, Panels, fuel heaters, fuel shutoff valve
ATA chapter 32: Landing Gear: Actuators, control valves, sensors, brake manifolds.