317197 AC 121922A CHAPTER 4. MRBR APPROVAL
36. MRBR APPROVAL PROCESS. The ISC Chairperson forwards the proposed MRBR to the manufacturer’s representative(s), and may invite the manufacturer to discuss the proposal. The manufacturer must present the proposed MRBR, as recommended or with revisions, to the FAA for approval as part of the Instructions for Continued Airworthiness. The manufacturer transmits the proposed MRBR to the MRB Chairperson for review and for approval and for submittal to AFS-300 for concurrence. Normally, the FAA approval process occurs within a time frame of no more than 90 days. Approval by other regulatory authorities will normally occur concurrently with that of the FAA. The manufacturer is responsible for publishing and distributing initial and revised MRBR’s and any supporting documents.
37. OTHER REGULATORY AUTHORITY APPROVAL OF THE MRBR. There may be a need to identify national regulatory differences that are not compatible, acceptable, or applicable to all regulatory authorities. When this condition exists, an appendix to the MRBR may be used to list these differences, with each being approved by the respective regulatory authority.
38. NON-APPROVAL PROCESS OF THE PROPOSED MRBR OR REVISION. The manufacturer shall coordinate non-approval of either the MRBR or revision with the MRB Chairperson, so that the ISC Chairperson may be notified in writing of such action. The non-approval letter shall include the specific reason(s) for the non-approval, and suggested guidance to make the MRBR proposal or revision approval.
39. MRBR OR REVISION IMPLEMENTATION. Air Carriers of the aircraft type should implement the MRBR, or revisions thereto, IAW established procedures. For air carriers of similar aircraft, and dependent on a particular air carrier’s qualifications and overall maintenance experience, adjustments to initial maintenance program intervals may be approved by the air carrier’s corresponding regulatory authority.
40. - 45. RESERVED.
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317197 AC 121122A CHAPTER 5. MRBR REVISIONS
46. ANNUAL REVIEW. Because the MRBR is intended to be an up-to-date document, the manufacturer, the ISC Chairperson, and the MRB Chairperson should conduct a joint review, at least annually, to determine the need for a revision. Results of these reviews should be documented by the MRB Chairperson for inclusion in the MRB historical file.
a. Proposed Changes. If needed, the manufacturer and the MRB will convene and evaluate any proposed changes. Proposed changes are submitted with supporting data to the MRB Chairperson. Approval or non-approval of the proposed changes is to be processed in the same manner as outlined for the initial MRBR approval/nonapproval.
b. Multiple Approvals. If an MRBR has been approved by more than one regulatory authority, then proposed changes will be evaluated by those approving authorities (as per letter of confirmation) before approval by the FAA. Published revisions to the MRBR shall then be reviewed by the corresponding regulatory authority for possible changes to an air carrier’s maintenance program.
47. - 55. RESERVED.
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317197 AC 121122A CHAPTER 6. RECOMMENDED MRBR FORMAT AND CONTENT
56. RECOMMENDATIONS. Each MRBR should be entitled “MRB Report,” and at a minimum, should contain the following, as appropriate:
a. A Revision Log.
b. A List of Effective Pages (including the revision status and corresponding dates).
c. A Title Page (containing the title of the MRBR and the report number, if any).
d. A Table of Contents.
et An Approval Page (containing the following statements):
(1) “This report outlines the initial minimum scheduled maintenance/inspection requirements to be used in the development of an approved continuous airworthiness maintenance program for the airframe, engines, systems, and components of the (aircraft make, model, and series).”
(2) “The requirements in the report have been developed using Maintenance Steering Group (MSG)- XX logic from the current MSG revision, or an alternative procedure as agreed upon by FAA, ISC, WG, .
etc.”
(3) “The Federal Aviation Administration (FAA) hereby approves that this report be used by U.S.- certificated air carriers of the (aircraft make, model, and series).”
Signed:
(Title of approving official) Date:
(Insert page for other regulatory authority approval, if applicable)
f. An ISC/MRB Personnel Listing (including ISC/MRB personnel, their organizational affiliation, and the capacity in which they serve).
g. The MRBR Preamble (The following information should be included in the Preamble of each MRBR):
(1) “This report outlines the initial minimum scheduled maintenance/inspection requirements to be used in the development of an approved continuous airworthiness maintenance program for the airframe, engines (on-wing engine only), systems, and components of (aircraft make, model, and series). These MRB requirements are a basis from which each air carrier develops its own continuous airworthiness maintenance program.”
(2) “The responsible FAA inspector shall ascertain that all of the applicable scheduled maintenance/ inspection requirements in this report are included in the air carrier’s initial continuous airworthiness maintenance program.”
h. Acronyms (All acronyms used in the MRBR should be defined. A listing of acronyms that should be contained in the MRBR are provided in Appendix 2).
i. Definitions (Definitions of technical terms should be included in the MRBR. The use of industry accepted definitions, such as those found in ATA MSG documents and World Airlines Technical Operations Glossary, should be used whenever possible).
j. Applicability (The MRBR must identify the specific aircraft make, model, and series, and the standard options. New options will be added to the MRBR summary sheets).
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AC 121122A 317197
k. Checks and Intervals (All tasks and their frequencies shall be identified in the MRBR. In certain cases, it may be necessary to establish and include task intervals less than that of an “A” check interval in the MRBR).
(1) Further guidance may also be provided in the MRBR regarding the means to escalate the initial minimum scheduled inspection/maintenance intervals to a level higher than that provided as initial intervals in the MRBR. This guidance will be unique to the aircraft.
(2) Escalation guidance should take into consideration the content of like checks and their repetitive intervals. A series or sequence of specified checks must be completed and the results found satisfactory before escalation of that type of check. Description, type of checks, and their intervals should be included in this section of the MRBR.
P. Maintenance program rules (The following rules should be contained in the MRBR):
(1) If there is an escalation procedure contained in the MRBR, the following rule applies: The individual check intervals listed in this report may be escalated following the completion of the required series or sequence of checks and the satisfactory review of check results and approval by the appropriate regulatory authority, or IAW the air carrier’s FAA-approved reliability program.
(2) Individual task intervals may be escalated based on satisfactory substantiation by the air carrier, and review and approval by its appropriate regulatory authority, or IAW the air carrier’s FAA-approved reliability program.
(3) Service Bulletins may be referenced by number in this report for clarifying the procedural aspects of this program; however, they shall not be used for escalation purposes.
(4) Task interval parameters expressed in the MRBR may be converted to an individual air carrier’s desired units, provided this conversion does not result in the air carrier exceeding the initial requirements of the MRBR.
(5) The use of nondestructive inspection (NDI) methods, such as “X-ray,” “ultrasonic,” “eddy current,’ ’ and ‘ ‘radio isotope,’ ’ which are approved by the manufacturer, can provide an alternative to the methods prescribed in this report. Each air carrier should notify its regulatory authority of the use of an acceptable alternative method.
(6) Within this report, the terms “check” and “inspection” are not intended to imply a level of skill required to accomplish a task.
(7) Life-limited parts must be retired IAW the limits established in the engine or aircraft Type Certificate Data Sheets (TCDS) or the Airworthiness Limitations section of the engine or aircraft manufacturer’s Instructions for Continued Airworthiness.
(8) After the accumulation of industry service experience, the ISC or MRB Chairpersons may request changes to the requirements of this MRBR.
m.
System/powerplant program rules (The following are recommended contents of the System Program Rules section of the MRBR):
(1) “MSG-3 (Specify the revision) logic was used to develop an on-wing scheduled maintenance program. With the exception of life-limited parts, this process does not normally include detailed off-wing shop maintenance procedures. Off-wing detailed procedures are controlled by individual air carriers and are derived from the air carrier’s reliability program or are IAW the manufacturer’s Instructions for Continued Airworthiness which are required by the Regulations.
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317197 AC 121922A
(2) Maintenance Significant Items.
(Insert MS1 list.)
(3) All MSI’s identified by the manufacturer have been subjected to the MSG.3 analysis. This process has resulted in the identification of maintenance tasks that are contained in this report. Those MSI’s for which a task was not generated during the analysis are identified as follows:”
(Insert MS1 listing for which no tasks were identified.)
n. Structural program rules (Structural inspection programs (SIP) are developed by the aircraft manufacturer to meet the inspection requirements for damage tolerance. The types of damage considered during program development are environmental deterioration (ED) (corrosion, stress corrosion), accidental, and fatigue. Some forms of ED are age related; therefore, inspections for this type of deterioration are controlled by calendar intervals. These calendar inspections, plus the requirements for detecting other types of ED, and accidental and fatigue damage (ID), are contained in the SIP. The following are recommended contents of the structural program rules section of the MRBR):
(1) “All aircraft in an air carrier’s or group of air carrier’s fleet shall be subject to the provisions of this report. These requirements include external and internal inspections, structural sampling and ageexploration programs, corrosion prevention and control programs, and additional supplemental structural inspections that may be required for fatigue-related items. A reliability program shall not be used to escalate the inspection interval, or delete the task, on any structural inspection item listed in the Airworthiness Limitations section. Initial check intervals for the SIP are expressed in calendar time, flight cycles, or flight hours.
No repeat inspection interval shall be escalated until at least one aircraft in an air carrier’s or group of air carrier’s fleet has been inspected within the initially defined interval listed in the MRBR.
(2) Structural inspection limitations listed in the aircraft manufacturer’s Airworthiness Limitations section will be referenced in the MRBR by document number.”
(Insert SSI sheets.)
o. Zonal program rules (The Zonal Inspection Program (ZIP) provides consolidation of a number of general visual inspection (GVI) tasks for each zone. A zonal inspection may include GVI tasks derived from MS1 and SSI. An MWSSI task that is in the ZIP must be cross-referenced, in the supporting documentation, as a zonal item; likewise, the zonal item must be cross referenced as an MWSSI task to ensure content and accountability. The following are recommended contents of the Zonal Program Rules section of the MRBR:)
(1) “The ZIP contains a series of GVI tasks. Detailed and special detailed inspections (DI) are not to be contained in the ZIP. Zonal inspection requirements apply only to zones.
(2) Access to zones should be easily accomplished and should not require the use of special tools.
Normally, the inspection aids to be used are a flashlight and/or inspection mirror. The entire visible contents of the zone must be inspected for obvious damage, security of installation, and general condition including corrosion and leaks.
(3) The following zones do not contain system installations but receive adequate surveillance from other maintenance or structural inspections tasks. Accordingly, these zones are not specified in the inspection requirements presented in the ZIP.”
(Insert listing of the zones not specified in the ZIP.)
(Insert zonal inspection sheets.)
p. Appendixes.
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AC 121122A 3l7D7
(1) Aircraft zones.
(2) National regulatory differences as mandated by other regulatory authorities. (Each shall be accepted by the respective authority.)
(3) Acronyms.
(4) Definitions.
(5) Other, as applicable.
57. - 65. RESERVED.
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3m97 AC 121922A Appendix 1 APPENDIX 1. POLICY AND PROCEDURES HANDBOOK (PPH) This appendix contains guidance to be used by the aircraft manufacturer, the ISC, and MRB Chairpersons during the development and review of the PPH. The following is an outline which contains items that should be included in the PPH.
I.
Recommended Contents A.
B .
C.
D.
E.
F.
G.
H.
I.
J.
K.
L.
M.
N.
0.
Introduction (identify MSG Baseline) Table of Contents Revision Control Organizational Outline (including the number and type of WG’s) and Duties and Responsibilities of Personnel
1. ISC
2.
Manufacturer(s)
3. WG Members
4. MRB Members and Advisors
5. Other Regulatory Authority Participants Technical and Maintenance Development Training for ISC and WG Members and FAA MRB Advisors) Program Timetables/Meeting Schedules Proposed Check Interval Parameters, if any, (for analysis and planning purposes) Analysis/Procedures to be Utilized (such as MSG-3) Forms that identify questions, actions, and transfers that may occur during WG activities Documentation of Meetings and General Administrative Procedures (The PPH should state that all formal meetings will be documented and that the minutes will be distributed by either the ISC Chairperson or a designee.)
Acronyms Definitions Appendixes MSG Document Other, as applicable
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317197 AC 121122A Appendix 2 APPENDIX 2. SUGGESTED ACRONYM LISTING FOR THE MRBR The following is a recommended listing of acronyms which may be contained in the acronym section of each MRBR.
AC Advisory Circular AD Accidental Damage AEG Aircraft Evaluation Group AEP Age Exploration Program ATA Air Transport Association of America CAM Canadian Airworthiness Manual CMR Certification Maintenance Requirement DI Detailed Inspection DTR Damage Tolerance Rating ED Environmental Deterioration FAA Federal Aviation Administration FAR Federal Aviation Regulations FD Fatigue Damage FMEA Failure Mode and Effects Analysis GVI General Visual Inspection ISC Industry Steering Committee JAA Joint Aviation Authorities JAR Joint Airworthiness Requirement MEA Maintenance Engineering Analysis MEL Minimum Equipment List MFG Manufacturer MMEL Master Minimum Equipment List MPP Maintenance Program Proposal MRB Maintenance Review Board MRBR Maintenance Review Board Report MRBPB Maintenance Review Board Policy Board MSC Maintenance Steering Committee MSG.1 Maintenance Steering Group - 1st Task Force MSG.2 Maintenance Steering Group - 2nd Task Force MSG.3 Maintenance Steering Group - 3rd Task Force MS1 Maintenance Significant Item MTBF Mean Time Between Failure MTBUR Mean Time Between Unscheduled Removal ND1 Nondestructive Inspection NDT Nondestructive Test PPH Policy and Procedures Handbook SD1 Special Detailed Inspection SID Supplemental Inspection Document SIP Structural Inspection Program SSI Structural Significant Item SSID Supplemental Structural Inspection Document TBD To Be Determined WG Working Group ZIP Zonal Inspection Program Page 1
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