2-13. OPERATOR MAINTENANCE/INSPECTION PROGRAM REQUIREMENTS.
a. Procedures for Development Personnel. Operators must have procedures in their maintenance/inspection program/manual that include all information from the fuel system airworthiness limitations. The operator’s maintenance/inspection program/manual shall state that personnel who edit maintenance manuals, job/task cards, and Engineering Orders (EO) must include the entire text of the airworthiness limitations, including the AMM standard wiring practice manual (SWPM) text that is required to be followed. (Merely referencing the AMM, SWPM, etc. is not acceptable.)
b. CDCCL Incorporation. Operators must ensure that the CDCCL “critical design features” are incorporated into the maintenance/inspection program/manual and are adhered to as written. Any proposed operator changes must be approved by the FAA Oversight Office. The CDCCL “critical design feature” identified above is just one of many that are included in the airworthiness limitations for the airplane. The CDCCLs “critical design features” must be included on the operators’ EOs and job/task cards.
c. Airplanes with FRM or IMM Installed. Operators who take delivery of “New Production Airplanes” (§ 121.1117(b)) either manufactured on or prior to December 27, 2010, or manufactured after December 27, 2010 that have either FRM or IMM installed must have FAA Oversight Office-approved airworthiness limitations (CDCCLs, inspections, or other procedures) from the ICA incorporated into their maintenance/inspection program/manual prior to putting the airplane into service.
d. Retrofitted Airplane Fleets. Operators who retrofit their fleet must incorporate the FAA Oversight Office-approved airworthiness limitations (CDCCLs, inspections, or other procedures) from the ICA into their maintenance/inspection program/manual prior to putting the airplane back into service.
e. Procedures to Maintain Placards. Operators must have procedures in their maintenance/inspection program/manual to maintain placards that have information about critical design features on the airplane as required by the airworthiness limitations.
f. Airworthiness Limitations with Approved CDCCLs. Airworthiness limitations that include FAA Oversight Office-approved CDCCLs, inspections, and other procedures are part of the airplane type design and therefore any changes must be approved by the FAA Oversight Office. Operators must have procedures in their maintenance/inspection program/manual that address any changes to airworthiness limitations. The procedures must include notification and be acceptable to the PI.
2-14. MAINTENANCE PROGRAM REVISIONS AFTER ALTERATIONS.
a. Before Return to Service (RTS). Section 121.1117(h), and similar provisions in parts 125 and 129 state-in-part, after the maintenance/inspection program is revised before returning an airplane to service after any alteration for which airworthiness limitations are required, the operator must revise the maintenance/inspection program for the airplane to include those airworthiness limitations prior to putting the airplane back in service.
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b. Incorporate TC Holder-Developed Revisions. The operator must incorporate the TC holder-developed Maintenance Review Board Report (MRBR) or maintenance implementation document revisions or other FAA Oversight Office approved fuel tank system airworthiness limitations (CDCCLs, inspections, and other procedures) into its maintenance or inspection program. The PI will approve the operator’s incorporation on OpSpec/LOA D097 Aging Aircraft Programs when the operator’s first FTFR compliant “New Production Airplane” is complete (ICA incorporated) or the first “Retrofit Airplane” is complete, whichever occurs first.
c. Free Text Area. The free text area of the OpSpec/LOA D097 must be utilized:
(1) To identify and record the document(s) (by document number, revision number, and date) used as the source of the FAA Oversight Office-approved FTFR airworthiness limitations.
(2) If this information is contained in the operator’s manual system, a reference to that location in their manual system must be recorded in the free text area.
(3) The operator must ensure that it has procedures in its manual that track any changes and approvals made to the FAA Oversight Office-approved FTFR ICA and airworthiness limitations.
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Appendix 1 APPENDIX 1. ACRONYMS A4A Airlines for America AC Advisory Circular ACO Aircraft Certification Office AEG Aircraft Evaluation Group AFS Flight Standards Service AL Airworthiness Limitation ALI Airworthiness Limitation Item ALS Airworthiness Limitation Section AMM Aircraft Maintenance Manual APU Auxiliary Power Unit ASI Aviation Safety Inspector CDCCL Critical Design Configuration Control Limitation CWT Center Wing Fuel Tank DAH Design Approval Holder FAA Federal Aviation Administration FIMM Flammability Impact Mitigation Means FQIS Fuel Quantity Indicator System FRM Flammability Reduction Means FTFR Fuel Tank Flammability Reduction FTS Fuel Tank Safety IMM Ignition Mitigation Means MRBR Maintenance Review Board Report MSG-3 Maintenance Steering Group – 3rd Task Force MSI Maintenance Significant Items NGS Nitrogen Gas System NTSB National Transportation Safety Board OpSpec Operations Specification PI Principal Inspector (This may include any or all of the affected Airworthiness or Operations) RGL Regulatory and Guidance Library SFAR Special Federal Aviation Regulations STC Supplemental Type Certificate SWPM Standard Wiring Practice Manual TC Type Certificate TCDS Type Certificate Data Sheet Page 1
Appendix 1 TSO Technical Standard Order
Appendix 2 APPENDIX 2. DEFINITIONS
a. Actual Gate Time. The time that the airplane is parked at a gate for servicing and passenger egress and ingress.
b. Aircraft Evaluation Group (AEG). The FAA Flight Standards Service (AFS) representatives who know the operational and maintenance aspects of the certification project and are responsible for determining the operational acceptability and continuing airworthiness requirements of newly certified or modified aircraft, engines, and propellers intended to be operated under the provisions of the Code of Federal Regulations (CFR). This function includes providing the FAA Oversight Office support in the review and approval of the initial and subsequent changes to the type design.
c. Aircraft Maintenance Manual (AMM). A manual developed by the manufacturer of a particular airplane that contains information necessary for the continued airworthiness of that airplane.
d. Airport Ambient Temperature. The official National Weather Service (NWS) temperature at the airport.
e. Airworthiness Limitations. In terms of this AC, mandatory maintenance of the fuel system that can include critical design configuration control limitation (CDCCL), inspections, or other procedures determined necessary to ensure that unsafe conditions do not occur and are not introduced into the fuel system as a result of maintenance actions, repairs, or alterations throughout the operational life of the airplane.
f. Applicant. In the context of this AC, an applicant is a person applying for design approval.
g. Available. In this AC, “available” relates to the requirement to use ground-conditioned air. In this regard it means a ground-conditioned air hookup is installed, and is operational at the gate. (Mobile ground-conditioned air carts are not required to be used.)
h. Center Wing Fuel Tank (CWT). A fuel tank located in the center of an airplane’s wing box. These tanks are typically located within the fuselage contour but may extend outside the fuselage contour into the wing.
i. Continued Airworthiness. Certified aircraft, engines, propellers, and appliances are safe to operate for the intended purpose; they are maintained safely throughout their service life;
the product meets its type design and is in a condition for safe operation.
j. Critical Design Configuration Control Limitations (CDCCL). An AL that preserves a critical feature of the airplane needed for the flammability reduction means (FRM) or ignition mitigation means (IMM) to perform their intended function and prevent the occurrence of an unsafe condition. The purpose of the CDCCL is to provide instructions to ensure these critical features are present throughout the life of the airplane, e.g., when alterations, repairs, or maintenance actions occur.
Appendix 2
k. Design Approval Holder (DAH). The holder of any design approval, including TC, amended TC, Supplemental Type Certificate (STC), amended STC, parts manufacturer approval, Technical Standard Order (TSO) authorization, letter of TSO design approval, and field approvals. In particular contexts, the term DAH may also refer to applicants for design approvals.
l. FAA Oversight Office. The Aircraft Certification Office (ACO) or office of the Transport Airplane Directorate having oversight responsibility for the relevant TC or STC, as determined by the Administrator. (See Appendix 3, FAA Oversight Offices for listing of appropriate offices.)
m. Field Approval. A design approval of a major repair or major alteration of an individual aircraft, aircraft engine, propeller, or appliance by an aviation safety inspector (ASI).
This is documented by completing and signing Block 3 of FAA Form 337, Major Repair & Alteration (Airframe, Powerplant, Propeller, or Appliance). We approve these major repairs or alterations by either examining data only or by physically inspecting, demonstrating, or testing the product.
n. Flammability Impact Mitigation Means (FIMM). Modifications developed by DAH for auxiliary fuel tanks that are required by Title 14 of the Code of Federal Regulations (14 CFR) part 26 to have an FRM or IMM installed. FIMM are only needed when the DAH or operator has determined that an auxiliary fuel tank installed by STC or field approval could have an adverse impact on the performance of an FRM or IMM.
o. Flammability Reduction Means (FRM). Any system or feature intended and designed to reduce the flammability exposure of a fuel tank either by affecting oxygen levels or by affecting fuel vapor concentration levels.
p. Flammable (With Respect to a Fluid or Gas). Susceptible to igniting readily or to exploding (14 CFR part 1). A non-flammable ullage is one where the fuel-air vapor is too lean or too rich to burn or is inert as defined below. For this AC, a fuel tank vapor space is considered flammable when the bulk average fuel temperature within the tank is within the flammable range for the fuel type being used. For any fuel tank that is subdivided into sections by baffles or compartments, the tank is considered flammable when the bulk average fuel temperature within any section of the tank is within the flammable range for the fuel type being used.
q. Flight Standards Service (AFS) Offices. FAA headquarters (HQ) offices responsible for developing guidance and policy applicable to transport category airplanes for AEG personnel and AFS field personnel (Airworthiness and Operations ASIs) in the conduct of their responsibilities.
r. Fuel Types. The Aircraft Flight Manual (AFM) lists the approved for use fuels for a given airplane type. Each fuel type has its own properties; those directly related to flammability are flash point and distillation characteristics. Property differences can occur in different batches of a given fuel type because of variations in the properties of the source crude oil and the refining process used to produce the fuel. The most widely used fuel types are JET-A/JET-A1, (with Page 2
Appendix 2 older airplanes approved for use of JET-B (JP-4)), per American Society for Testing and Materials (ASTM) Specification D1655-11b, Standard Specification for Aviation Turbine Fuels.
s. Hazardous Atmosphere. An atmosphere that may expose maintenance personnel, passengers, or flightcrew to the risk of death, incapacitation, impairment of ability to self-rescue (escape unaided from a confined space), injury, or acute illness.
t. Ignition Energy. The minimum amount of energy required to ignite fuel vapors.
u. Ignition Mitigation Means (IMM). A system or feature intended and designed to prevent overpressure of a fuel tank following ignition of fuel or vapor in the tank.
v. Inert. When the bulk average oxygen concentration within each compartment of the fuel tank is 12 percent or less from sea level up to 10,000 feet altitude, then linearly increasing from 12 percent at 10,000 feet to 14.5 percent at 40,000 feet altitude, and extrapolated linearly above that altitude.
w. Inerting. A process where a noncombustible gas is introduced into the ullage of a fuel tank so that the ullage becomes non-flammable.
x. Instructions for Continued Airworthiness (ICA). Documentation that sets forth instructions and requirements for maintenance that is essential to the continued airworthiness of an aircraft, engine, or propeller.
y. Main Fuel Tank. Title 14 CFR part 25, § 25.981(b)(3)(iii) defines the main fuel tank as: “…a fuel tank that feeds fuel directly into one or more engines and holds required fuel reserves continually throughout each flight.” The functions of the main tanks are immediately available and operate without immediate supervision by the flightcrew in the event of failure or inadvertent depletion of fuel in an auxiliary tank. Generally, main tanks are those dedicated to the feed of the engines during engine feed isolation.
z. Maintenance Instructions. Recommended periods for cleaning, inspection, adjustment, testing, lubrication, degree of inspection, applicable wear tolerances, and recommended work necessary for each part of the airplane and its engine auxiliary power units (APU), propellers, accessories, instruments, and equipment to provide for continued airworthiness of the airplane. Recommended overhaul periods and necessary cross-references to the ALS of the maintenance manual are also included (see 14 CFR part 25, appendix H, § 25.3(b); and the current edition of appendix A of AC 26-1, Part 26, Continued Airworthiness and Safety Improvements, for additional information.)
aa. Maintenance Review Board Report (MRBR). Document intended for use by air carriers. It contains the initial minimum scheduled maintenance and inspection requirements for a particular transport category aircraft and on-wing engine program. Air carriers use the MRBR and its associated requirements to develop maintenance programs. (See the current edition of AC 121-22, Maintenance Review Board Report Maintenance Type Board, and OEM/TCH Inspection Program Procedures, for additional information.)
Appendix 2 bb. Maintenance Significant Item (MSI).
(1) Under Maintenance Steering Group – 3rd Task Force (MSG-3), items identified by the design approval holder whose failure could cause one of the following effects:
• It could affect safety on the ground or in flight,
• It could be undetectable during operations,
• It could have a significant impact on operations, or
• It could have a significant economic impact.
(2) In terms of development of maintenance and inspection instructions, MSIs include systems, subsystems, modules, components, accessories, units, and parts.
cc. Maintenance Steering Group – 3rd Task Force (MSG-3). A voluntary structured process developed by the industry and maintained by Airlines for America (A4A) to make decisions used to develop maintenance and inspection tasks and intervals for an airplane.
dd. Maintenance Working Group (MWG). A working group of maintenance specialists from participating operators, the prime manufacturer, and the regulatory authority whose function is to develop airplane maintenance programs.
ee. Maximum Payload Capacity. Is defined in 14 CFR part 119.
ff. Normally Emptied. Defined in § 26.31(b) as: “…a fuel tank other than a Main Fuel Tank.” Main Fuel Tank is defined in § 25.981(b), and expanded above.
gg. Operational. With regard to ground-conditioned air, means the ground air source is functional and has the capacity to provide air to the airplane.
hh. Operator. Person who uses, causes, or authorizes another to use aircraft for air navigation, including piloting the aircraft.
ii. Transport Category Airplanes. For the purposes of this AC, the group consists of turbine-powered transport category airplanes, provided that the TC for the airplane was issued after January 1, 1958, and that the airplane has either a maximum TC’d passenger capacity of 30 or more, or a maximum payload capacity of 7,500 pounds or more, resulting from the original certification of the airplane.
Appendix 3 APPENDIX 3. FAA OVERSIGHT OFFICES Airplane Manufacturer FAA Oversight Office ATR – GIE Avions de Transport Régional Transport Airplane Directorate, International Branch, ANM-116 Airbus Transport Airplane Directorate, International Branch, ANM-116 BAE Transport Airplane Directorate, International Branch, ANM-116 Boeing—Seattle Area Seattle Aircraft Certification Office (ANM– 100S) and/or Boeing Aviation Safety Oversight Office (ANM–100B) Bombardier New York Aircraft Certification Office EADS CASA Transport Airplane Directorate, International Branch, ANM-116 deHavilland New York Aircraft Certification Office Dornier Transport Airplane Directorate, International Branch, ANM-116 Embraer Transport Airplane Directorate, International Branch, ANM-116 Fokker Transport Airplane Directorate, International Branch, ANM-116 Lockheed Martin Atlanta Aircraft Certification Office Boeing—Long Beach (McDonnell-Douglas) Los Angeles Certification Office (ANM–100L and/or Boeing Aviation Safety Oversight Office (ANM–100B) SAAB Transport Airplane Directorate, International Branch, ANM-116
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