Service bulletins or service instructions are two of several types of publications issued by airframe, engine, and component manufacturers. The bulletins may include: purpose for issuing the publication; name of the applicable airframe, engine, or component; detailed instructions for service, adjustment, modification or inspection, and source of parts, if required; and estimated number of man-hours required to accomplish the job.

The manufacturer’s aircraft maintenance manual contains complete instructions for maintenance of all systems and components installed in the aircraft. It contains information for the mechanic who normally works on components, assemblies, and systems while they are installed in the aircraft, but not for the overhaul mechanic. A typical aircraft maintenance manual contains:

The manufacturer’s overhaul manual contains brief descriptive information and detailed step-by-step instructions covering work normally performed on a unit that has been removed from the aircraft. Simple, inexpensive items, such as switches and relays where overhaul is uneconomical, are not covered in the overhaul manual.

The structural repair manual contains the manufacturer’s information and specific instructions for repairing primary and secondary structures. Typical skin, frame, rib, and stringer repairs are covered in this manual. Also, included are material and fastener substitutions and special repair techniques.

The illustrated parts catalog presents component breakdowns of structure and equipment in disassembly sequence. Also, included are exploded views or cutaway illustrations for all parts and equipment manufactured by the aircraft manufacturer.

The wiring diagram manual is a collection of diagrams, drawings, and lists that define the wiring and hook up of associated equipment installed on airplanes. The data is organized in accordance with the Air Transport Association ATA iSPec 2200 specification.

The Code of Federal Regulations (CFRs) were established by law to provide for the safe and orderly conduct of flight operations and to prescribe airmen privileges and limitations. A knowledge of the CFRs is necessary during the performance of maintenance, since all work done on aircraft must comply with CFR provisions.

A primary safety function of the FAA is to require correction of unsafe conditions found in an aircraft, aircraft engine, propeller, or appliance when such conditions exist and are likely to exist or develop in other products of the same design. The unsafe condition may exist because of a design defect, maintenance, or other causes. Title 14 of the CFR part 39, Airworthiness Directives, defines the authority and responsibility of the administrator for requiring the necessary corrective action. The ADs are published to notify aircraft owners and other interested persons of unsafe conditions and to prescribe the conditions that the product may continue to be operated. Furthermore, these are federal aviation regulations and must be complied with unless specific exemption is granted.

There are two categories of ADs:

Also, ADs may be a one-time compliance item or a recurring item that requires future inspection on an hourly basis (accrued flight time since last compliance) or a calendar time basis.