Explainer
Part 121 and Part 135 Operator Manuals
The Short Answer
One Required Manual, Several Books
The regulations do not list four manuals. 14 CFR 121.133 tells a Part 121 certificate holder to prepare and keep current a manual for flight, ground operations, and management personnel, and 135.21 does the same for Part 135. What operators call the general operations manual, the general maintenance manual, the training manual, and the hazmat manual are books that together hold that required content. The rules explicitly allow the split.
This is the company-level layer. The aircraft-level layer sits underneath it, and is covered in the flight operations library, AFM and quick reference handbook, and minimum equipment list pages. Safety management has its own document, described in the SMS manual explainer.
The Set
The Four Books Operators Keep
- General operations manual
- The manual the regulations actually require: 121.133 for air carriers and 135.21 for Part 135. It is the company-wide manual for flight, ground, and maintenance personnel. Operators often call it the general operations manual or the operations manual; the rule names no particular title.
- Maintenance manual
- Part of the same required manual. 121.135(b) lists maintenance, preventive maintenance, servicing, time limits, and airworthiness inspection items, and 135.23(o) calls for the approved aircraft inspection program where applicable. Operators commonly publish this as a separate general maintenance manual.
- Training manual
- For a Part 121 carrier the manual must include each training program curriculum required by 121.403. Part 135 operators that need a training program must have it approved by the FAA before they use it.
- Hazardous materials manual
- Procedures and information for people who accept, reject, handle, store, package, or load items for transport. They are required by 121.135(b)(25) and 135.23(p), and operators often publish them as their own manual.
Part 121
What 121.135 Puts Inside
Section 121.135(b) lists 26 items. They include general policies; crewmember and management duties; dispatch and operational control; en route and airport information drawn from the operations specifications; weight limits; emergency equipment and procedures; succession of command; weather procedures; each training program curriculum required by 121.403; instructions for maintenance, preventive maintenance, and servicing; time limitations for overhauls, inspections, and checks; refueling; airworthiness inspections; weight and balance; accident notification; and any other information or instructions relating to safety.
The manual must give personnel the information to do their jobs with a high degree of safety, be in a form that is easy to revise, and not conflict with a federal regulation or the certificate holder's operations specifications. A complete copy must be kept at the principal base of operations. The maintenance part may be printed or in another form acceptable to the Administrator.
Part 135
What 135.21 and 135.23 Add
Section 135.23 lists the contents as items (a) to (s). Among them are the management persons and who may exercise operational control; weight and balance procedures; copies of the operations specifications or extracted information; accident notification; procedures for confirming that airworthiness inspections were made and the aircraft was returned to service; reporting and clearing mechanical irregularities; release or continuation of flight with inoperative equipment; refueling; the pilot briefing; flight locating; emergency and evacuation procedures; the approved aircraft inspection program where applicable; and the hazmat procedures.
Two features differ from Part 121. A Part 135 operator that uses only one pilot is outside 135.21(a), and the FAA may authorize a deviation where a small operation does not need part of the manual. And the maintenance content is spread through the Part 135 list instead of sitting in one block of items.
Hazardous Materials
The Hazmat Procedures
Both manuals must carry procedures and information for each crewmember and each person who performs or directly supervises acceptance, rejection, handling, storage incidental to transport, packaging of company material, or loading. The text is sufficient only if it helps those people recognize packages that are marked or labeled as hazardous materials, or that show signs of undeclared ones. The required content is:
- How to reject packages that do not conform to the Hazardous Materials Regulations or that appear to contain undeclared hazardous materials.
- How to meet the incident and discrepancy reporting requirements in 49 CFR 171.15, 171.16, and 175.31.
- The operator's hazmat policy, including whether it is authorized to carry hazardous materials or prohibited from carrying them.
- If the operations specifications permit carriage: procedures for acceptance, handling, storage, loading, Notice to the Pilot in Command, and for aircraft parts and consumables that are regulated.
The manual is separate from the training. Under 121.1003 and 135.503 the hazmat training program must be approved by the FAA before it is implemented, and under 121.1005 and 135.505 a person may not do those job functions without completing the operator's FAA-approved initial or recurrent training within the past 24 months.
Access
Who Must Have a Copy
Under 121.137 the carrier furnishes the manual or its appropriate parts, and all changes and additions, to ground operations and maintenance personnel, crewmembers, and FAA representatives assigned to it. Each person who holds a copy keeps it up to date and has it accessible when performing assigned duties. Part 135 says the same in 135.21(d) through (f), and adds that the appropriate parts must be accessible at all times when flight, ground, and maintenance personnel are performing their duties. Supplemental operations under Part 121 get a matching rule in 121.139. In each case the information must be displayed clearly and be retrievable in the English language.
Since the 2023 rule (88 FR 34443), a paper manual shows the date of last revision on every page, and an electronic manual shows it in a way a person can immediately ascertain. The details for tablets and portals, including OpSpec A025, are in FAA rules for electronic manuals. Changes an operator makes to manufacturer maintenance data in its own maintenance manual are covered in operator maintenance manuals under 43.13(c).
Keeping It Current
What a Publications Team Sees
The practical trouble is rarely a missing manual. It is that one rule change touches several books, and each book has its own readers. A change to the hazmat policy lands in the operations book, the hazmat book, and the training curriculum; a change to the inspection program lands in the maintenance and operations books. Keeping one source for repeated content, a revision record for each book, and a clear owner for each part is what lets every copy-holder show a current page.
Shakewell writes and revises operator maintenance manuals, including general maintenance manuals.
FAQ
Questions We Hear
Is a general operations manual required?
A manual is required, and under 14 CFR 121.133 and 135.21 it serves flight, ground, and maintenance personnel. The rules do not use the name general operations manual. A Part 135 operator that uses only one pilot is outside 135.21(a), and the FAA may authorize a deviation for a small operation where part of the manual is not needed. Read the rule and your operations specifications for your own case.
Can the manual be split into several books?
Yes. 14 CFR 121.135(b) says the manual may be in two or more separate parts, as long as together they contain all the listed information and each part contains what is appropriate for its group of personnel. Part 135 has no equivalent sentence, but 135.21(d) refers to appropriate portions being furnished.
Who must receive a copy?
Under 121.137 the carrier furnishes the manual, or the appropriate parts, and every change to ground operations and maintenance personnel, crewmembers, and the FAA representatives assigned to it. Under 135.21(d) flight crewmembers and FAA representatives are furnished copies, and the manual must be made available to maintenance and ground personnel. Each person who is furnished a copy keeps it up to date.
Does the revision-date rule apply to every one of these manuals?
It applies to each manual required by 121.133 and to the Part 135 manual under 135.23. A paper manual shows the date of last revision on each page; an electronic one shows it where a person can immediately ascertain it. Our guide to FAA rules for electronic manuals covers how that works on a tablet.
Is the airplane flight manual part of this set?
It is a separate requirement. 121.141 requires a current approved airplane flight manual for each type of airplane, and lets the operator carry its own manual in place of it if the flight manual content is clearly identified. The AFM and quick reference handbook explainer covers that document.
Does this page give legal advice?
No. It summarizes the text of the rules as published in the eCFR. Which paragraphs apply to a certificate holder depends on its operations specifications and the FAA office that oversees it.
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Maintenance Manuals That Stay Current
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