AC 120-85A

Historical

Advisory circular · Air Cargo Operations

A newer version is currentThis is a historical version. AC 120-85B is the version in force, approved January 25, 2022.
Approved
June 25, 2015
Last reviewed
August 22, 2024
Cancels
AC120-85
Cancelled by
AC120-85B
Family
AC 120-85 · 3 versions
Revision
A
14 CFR parts
21, 25, 43, 45, 119, 121, 145, 234, 382

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 22, 2025.

Show pages 1–12

Par 2.2.2 Page 7

2.2.2.7.1 A method for calculating the weight of supernumeraries and their carry-on and checked baggage, such as actual weight or standard average weight. Refer to AC 120-27 for guidance on calculating weights;

2.2.2.7.2 Any special procedures or limitations when carrying supernumeraries aboard an aircraft. These limitations may be specified as part of the type design in the Type Certificate Data Sheet (TCDS) or a limitation in the 14 CFR part 25 exemption for the carriage of supernumeraries; and

2.2.2.7.3 Instructions for documenting the weight of supernumeraries, and for communicating the information to the pilot in command (PIC) or other authorized, trained, and qualified personnel for determining W&B.

Par 2.3.1 Page 8 SECTION 2.3. CLASSIFYING CARGO COMPARTMENT FOR FIRE

SUPPRESSION, CARGO LOADING SYSTEM COMPONENTS, INSTALLED NETS,

AND SMOKE BARRIERS

2.3.1 Classification of Cargo Compartments for Fire Suppression. Aircraft cargo compartments are designed to accept and restrain cargo in various ways. Cargo compartments are classified as class A, B, C, or E in 14 CFR parts 25 and 121, depending on accessibility and fire protection requirements. Some cargo compartments accept ULDs and some do not. In general:

2.3.1.1 Class A compartments are accessible by the flightcrew for firefighting, usually from the flight deck or areas adjacent to the flight deck.

2.3.1.2 Class B compartments are accessible by the flightcrew for firefighting.

2.3.1.3 Class C compartments are used on passenger aircraft for carrying baggage or other cargo. These compartments require a fire suppression and detection system controlled from the pilot or flight engineer station. The compartment is not accessible to the flightcrew during flight.

2.3.1.4 Class E compartments are on airplanes used only for the carriage of cargo.. These compartments are on both the main deck and lower lobe areas and, require fire detection systems.

2.3.2 Cargo Compartments Designed to Accept ULDs. These compartments are equipped with an aircraft CLS designed to restrain ULDs in the aircraft. CLSs also position ULDs, enabling them to move easily in and out of the aircraft. The CLS comprises various assemblies, such as restraint locks, side rails, and ball and roller conveyors. Some CLSs are powered, and some may be installed in main deck and/or lower deck compartments. When the flightcrew and/or other persons are seated on the same deck forward of the CLS, a smoke barrier is installed (as applicable) between the CLS and those persons.

2.3.3 Cargo Compartments Not Designed to Accept ULDs. These cargo compartments are called bulk compartments, and may have vertical or horizontal nets. Depending on its design and purpose, the net may restrain cargo from shifting vertically, longitudinally, and laterally within the compartment or from shifting onto the cargo door or cargo door area within the compartment.

Bulk compartments protect aircraft systems and structures against damage from shifting cargo for all flight and landing conditions.

NOTE: Care should be taken when loading bulk cargo in these compartments to ensure that it does not block fire detection sensors or fire suppression agent nozzles, if installed.

2.3.4 Substituting CLS Components. An operator may substitute aircraft CLS components under several different procedures, depending on the certification method for the components being substituted. Substitution also may involve replacing CLS components, or subcomponents of an aircraft cargo restraint assembly, with those of another design. If an operator substitutes a CLS component, the operator must have a procedure that addresses:

Par 2.3.4 Page 9

• The load-bearing components that the operator may substitute;

• The level of substitution, such as a complete assembly or parts of an assembly, the operator allows and the conditions that support each process; and

• The FAA-approved data used.

NOTE: CLS components are certificated under methods such as a Parts Manufacturer Approval (PMA), Technical Standard Order (TSO), Production Certificate (PC), TC, amended TC, STC, or under rules governing owner-produced parts.

2.3.5 Substituting PMA Products. An operator may substitute aircraft CLS components manufactured under a PMA. Installation data and any limitations may be found in the:

• The component maintenance manual (CMM);

• The manufacturer’s illustrated parts catalog or the air carrier’s supplemental manual;

• The operator’s instructions based on FAA-approved data, the aircraft manufacturer, or STC holder; and

• The manufacturer’s Service Bulletins (SB) or service letters.

2.3.6 Substituting TSO Products. An operator may substitute CLS components manufactured under a TSO if the operator has procedures to determine whether the unit is eligible for installation. An operator may substitute products approved under a TSO using information from:

• SBs;

• STCs;

• Aircraft manufacturer’s TC;

• CMMs; or

• Manufacturer’s illustrated parts catalogs.

2.3.7 Substituting PC, TC, Amended TC, AND STC Products. Parts can be approved through the PC, TC, amended TC, and STC processes. These processes include instructions for interchanging CLS components. An operator may substitute these components using the following source documentation for these processes:

• Type Certificate Data Sheet (TCDS);

• SBs, service letters, or equivalent FAA-approved data; and

• Manufacturer’s instructions for continued airworthiness (ICA).

2.3.8 Substituting Owner-Produced Parts. Title 14 CFR part 21 indicates an operator may manufacture parts for use on its own aircraft. In such cases, an operator must have processes to:

• Identify components manufactured for the aircraft CLS in its maintenance program;

• Ensure another operator or vendor does not sell or distribute the parts it manufactures;

Par 2.3.8 Page 10

• Show its owner-produced parts meet the equipment manufacturer CLS type design; and

• Maintain the continued airworthiness of the owner-produced part.

2.3.9 Addressing CLS Component Discrepancies. An operator may address aircraft CLS component discrepancies by replacing or repairing the applicable component. If the operator discovers systemic problems with the reliability of its components, the operator should report such problems to the component manufacturer. An operator’s CASS should track all cargo loading component discrepancies to measure the performance and effectiveness of the operator’s maintenance and inspection program.

2.3.10 Replacing a CLS Component. An operator may replace a CLS component with a new, rebuilt, overhauled, or repaired serviceable component. This component must meet requirements for installation on the particular aircraft.

2.3.11 Repairing a CLS Component.

2.3.11.1 Operator Responsibility. An operator may repair a component on the aircraft, or may have a vendor repair a component. Under certain circumstances, an accepted manual may allow minor repairs using FAA-accepted data. The repair vendor may be under the direct control of an operator, or may be a vendor the operator designates. The operator has primary responsibility for determining that:

2.3.11.1.1 The component meets applicable regulatory requirements, and

2.3.11.1.2 The repair vendor is authorized to repair the component.

2.3.11.2 Vendor Repair. CLS components repaired by a vendor should undergo a receiving inspection using operator procedures. The component should also have documentation to

(1) confirm each component is certified as serviceable, and (2) provide traceability to the data used for repair. The documentation should include:

2.3.11.2.1 Identity of the company that owns the component;

2.3.11.2.2 FAA repair station certificate number, if applicable, and vendor name;

2.3.11.2.3 Component part number;

2.3.11.2.4 Component serial number, if applicable;

2.3.11.2.5 Component nomenclature;

2.3.11.2.6 Component times and/or cycles, if applicable;

2.3.11.2.7 Quantity of components;

2.3.11.2.8 Specifications used for repair;

Par 2.3.11 Page 11

2.3.11.2.9 Certification statement of procedures used;

2.3.11.2.10Traceability documentation; and

2.3.11.2.11Signature of an authorized agent.

2.3.11.3 Retention of Repair Records. The operator must retain its repair records in accordance with its established procedures to comply with the requirements of § 121.380.

2.3.12 CLS Components in the Minimum Equipment List (MEL).

2.3.12.1 Dispatch Deviation Procedures. An operator must ensure the aircraft MEL contains adequate instructions, or references an appropriate manual, for dispatch deviation procedures that describes:

2.3.12.1.1 The total number of items installed and minimum number required for dispatch;

2.3.12.1.2 The loading limitations because of missing or defective equipment;

2.3.12.1.3 The references showing location of loading restrictions;

2.3.12.1.4 The appropriate category for repair; and

2.3.12.1.5 The instructions for ensuring MEL limitations are included in W&B computations and the load plan.

2.3.12.2 Procedures for Inoperative or Missing CLS Components. An operator should include procedures for inoperative or missing CLS components in the operator MEL. These procedures should include any requirements for:

2.3.12.2.1 Reconfiguration of the aircraft, if necessary;

2.3.12.2.2 Voiding of adjacent positions, if necessary;

2.3.12.2.3 Accounting for limitations;

2.3.12.2.4 Notification to the PIC and other appropriate personnel the operator deems necessary of the missing components;

2.3.12.2.5 Instructions for ensuring MEL limitations and/or restrictions are included in W&B computations and the load plan; and

2.3.12.2.6 Annotation in the aircraft maintenance logbook.

2.3.13 Installed Nets in the Maintenance Program. An operator maintenance program must contain procedures for maintenance and inspection of installed vertical and horizontal cargo compartment nets and 9G barrier nets.

Par 2.3.13 Page 12

2.3.13.1 The Program Should Encompass:

2.3.13.1.1 In-house or vendor repair procedures;

2.3.13.1.2 Receiving inspection procedures; and

2.3.13.1.3 Serviceability limitations.

2.3.13.2 Authorized Vendor List. The operator should include vendors on its authorized vendor list, and any required inspection item requirements.

2.3.14 Smoke Barriers.

2.3.14.1 Smoke Barrier Control Procedures. All smoke barriers act as a blockade between the cargo and crew, preventing smoke and flames from entering the passenger cabin and flight deck areas of the aircraft. They can be permanent or attachable and in a variety of forms, such as doors or curtains. An operator must have procedures to control the airworthiness and subsequent operational serviceability of smoke barriers. The operator should provide aircraft-specific training on the description, operation, function, and preflight of smoke barriers.

2.3.14.2 Inspection. Inspect the overall condition of the smoke barrier curtain, if installed, or cockpit door seal, barrier net assembly, or solid bulkhead. Ensure that the net (if used) has the proper rating for its intended G-loading. Inspections of the smoke barrier should include, at a minimum:

2.3.14.2.1 The smoke barrier curtain must be free of tears, holes, and cuts to prevent smoke from entering the forward cabin and flight deck;

2.3.14.2.2 The cockpit door seal, for condition and integrity;

2.3.14.2.3 The barrier net, for condition and security (i.e., check for frayed straps, hardware integrity, and proper markings);

2.3.14.2.4 Cargo compartment retention nets, for condition and security;

2.3.14.2.5 The solid bulkhead, for condition and security; and

2.3.14.2.6 The required placards (such as loading, fire suppression, and so forth) for condition, legibility, and security.

Par 2.4.1 Page 13 SECTION 2.4. UNIT LOAD DEVICES AND CARGO RESTRAINT DEVICES

2.4.1 Restraints. Aircraft cargo restraint methods come in two general categories: primary and supplemental. An operator has overall responsibility for ULDs and other cargo restraint devices and should have FAA-accepted procedures to control the operational serviceability of them, whether a primary or a supplemental restraint. When primary or supplemental restraint is attached directly to the aircraft structure, see Section 2.8, Transport of Special Cargo, for additional guidance.

2.4.2 Primary Restraint. This is the restraint of the cargo payload to the aircraft structure for regulatory load conditions (e.g., flight and emergency landing). This restraint secures cargo in the forward, aft, vertical, and lateral directions. Primary restraint is used to secure:

2.4.2.1 Cargo:

2.4.2.1.1 To a pallet using applicable net (net is the primary restraint);

2.4.2.1.2 Within a container (container is the primary restraint); or

2.4.2.1.3 To the aircraft structure (straps, ropes, etc. is the primary restraint).

2.4.2.2 ULD—to the aircraft structure using the CLS (e.g., locks and side rails).

2.4.2.3 WBM Provisions. Some airplane WBMs may provide additional tiedown to the aircraft structure to restrain ULDs if the following conditions exist:

2.4.2.3.1 The ULD weight limit is limited either by restraint configurations or by missing and/or inoperative restraints.

2.4.2.3.2 The ULD is loaded to a weight greater than allowable for the chosen loading position with all restraints operative, and a greater weight is allowed by the aircraft WBM with tiedown (e.g., the floor is more capable than the restraint system).

NOTE: See Section 2.8 for additional guidance.

2.4.3 Supplemental Restraint. Supplemental restraint is additional restraint that prevents shifting and is used to stabilize cargo to a pallet or container. When supplemental restraints are attached to the CLS or aircraft structure, it creates a parallel load path to the ULD, therefore classified as special cargo. See Section 2.8 for additional guidance. An exception would be stabilization straps in a certified bulk compartment.

2.4.4 ULDS and Other Cargo Restraint Devices.

2.4.4.1 ULD Definition. A ULD is a device for grouping, transferring, and restraining cargo for transit. It may consist of a cargo pallet and cargo net combination or a container as defined in the current editions of National Aerospace Standard (NAS) 3610, Cargo Unit Load Devices – Specification For; Aerospace Standards (AS) 36100, Air Cargo Unit Load Devices – Performance Requirements and Test Parameters; and TSO-C90, Cargo Pallets, Nets and

Par 2.4.4 Page 14 Containers (Unit Load Devices). These documents do not include a cargo pallet and cargo strap combination. When restraining a pallet and net ULD into the aircraft, the aircraft may be the weakest link in the certified load path. The term ULD includes the following equipment:

2.4.4.1.1 Pallets and nets.

2.4.4.1.2 Certified and non-certified aircraft containers.

2.4.4.2 Types of ULDs.

2.4.4.2.1 Background.

2.4.4.2.1.1 Certified ULDs are defined in aircraft WBMs and require no further analysis. However, non-certified ULDs and other payloads require further analysis to determine if the aircraft and restraint system is structurally adequate.

2.4.4.2.1.2 ULDs designs may exceed the structural capability of an aircraft. To preclude failures of the aircraft cargo restraint system the requirements of the aircraft WBM must be observed.

2.4.4.2.2 Certified ULD. A ULD meeting the requirements of TSO-C90; STC requirements, if applicable; or other FAA-approved certification standards. A certified ULD is structurally capable of restraining a load and/or protecting the aircraft systems and structure.

Only ULDs that are permitted by the aircraft WBM (TC or STC) are certified for use on that aircraft. To remain a certified ULD for an aircraft, the ULD must be restrained by the aircraft’s CLS, such as pallet locks and side guides. A certified pallet and a certified net can be combined and certified as a unit. The operator should have on file for all its certified ULDs an FAA approval letter, certificate, or other certifying document, such as a conformance certificate provided by the ULD equipment manufacturer.

2.4.4.2.3 Certified Cargo Pallet and Net (ULD). Most operator WBMs recognize a TSO cargo pallet and net combination as the primary restraint for unitized cargo. A cargo pallet net is the only restraint device that takes the shape of the cargo while restraining the load in all directions, so that the load is spread to the net fittings and pallet edge rails.

2.4.4.2.4 Non-Certified ULDs. A ULD that does not meet the TSO-C90 or PMA certification requirements, and/or is not listed in the aircraft WBM (TC or STC). Non-certified ULDs should meet a standard (see Appendix B, Guidance Material, for suggested standards).

The operator should have documentation stating its design criteria for manufacturing the noncertified ULD.

2.4.4.2.5 Active ULDs.

2.4.4.2.5.1 Active ULDs are ULDs with active temperature control systems for transporting temperature sensitive cargo. Unlike the typical ULD, active ULDs are capable of heating and/or refrigerating as required. These systems consist of a highly insulated container with a battery operated heating/cooling system integrated into the construction of the container.

Active ULDs are intended to be operating during flight. Active ULDs are battery powered in

Par 2.4.4 Page 15 flight and are only recharged while on the ground. The “active” components of these units typically consist of a vapor cycle refrigeration/heat pump type system that is powered by various types of large batteries, depending on the manufacturer.

2.4.4.2.5.2 Only Active ULDs approved under part 21, § 21.8(d) or § 21.305(d); a TC; or an STC may be used on U.S.-registered aircraft and marked with an “Active Unit Load Device” placard (see Appendix I, Active Unit Load Device Marking). Additionally, if an operator intends to deploy these containers in their fleet, they should have procedures in their manuals to ensure only containers that are properly prepared, and which meet the handling and airworthiness requirements of the manufacturer, are carried on an aircraft. To carry these devices, operators should incorporate or reference the pertinent parts of the device’s certification documents into its manual. These may include:

1. Required markings, placards, and labeling;

2. ICAs to include proposed limitations and restrictions necessary to safely carry the device on an aircraft; and

3. Operating instructions for the device.

NOTE: Hazmat procedures in Title 49 of the Code of Federal Regulations (49 CFR) may apply to the container’s contents.

NOTE: A recodification of part 21, effective April 2011, changed the reference § 21.305(d) to § 21.8(d).

2.4.4.2.6 Temperature-Controlled Shipping Containers. Temperature-controlled shipping containers are devices designed to maintain their contents within strict temperature controls. These devices may bear a TSO, STC; PMA, or be allowed by the TC. These units should be approved in the limitations section of the certification document for use with certain Net-Pallet combinations. To carry these devices, operators should incorporate or reference the pertinent parts of the device’s certification documents into its manual. These may include:

2.4.4.2.6.1 Required markings, placards, and labeling;

2.4.4.2.6.2 ICAs, to include proposed limitations and restrictions necessary to safely carry the device on an aircraft; and

2.4.4.2.6.3 Operating instructions for the device.

NOTE: Hazmat procedures in 49 CFR may apply to the container’s contents.

2.4.4.3 Other Restraint Devices.

2.4.4.3.1 Other Types of Cargo Restraint Devices. The operator may use cargo restraints such as straps, ropes, cables, and nets. These restraints must be approved per aircraft manufacturer W&B documentation or STC holder documentation. The operator’s manual should

Par 2.4.4 Page 16 address their use, serviceability limitations and a process to follow if failed restraints are identifed while in use. If the operator doesn’t use an authorized cargo pallet/net combination as the primary restraint, the operator’s manual should have policies and procedures to address this issue. For example, if a strap is used as the primary restraint, the cargo may be:

• Loaded in an aircraft compartment that meets the type design for compartment restraint, or

• Restrained by cargo straps or other authorized devices to the aircraft as described in the aircraft’s manual, an STC supplement, or a WBM.

2.4.4.3.2 Certified Straps. These devices should meet the requirements of TSO-C172, Cargo Restraint Strap Assemblies. In it, the FAA describes the minimum performance standards (MPS) by which cargo restraint strap assemblies are approved and identified with applicable TSO markings.

2.4.5 Determining ULD Compatibility. It is critical to safety of flight for the operator to have procedures confirming that ULDs on board an aircraft are compatible with the aircraft, regardless of who owns the ULD. Not all ULDs are authorized as compatible with all aircraft, so an operator should have procedures for:

2.4.5.1 Compatibility. Ensure certified and non-certified ULDs are compatible with the aircraft and do not present a hazard to the aircraft.

2.4.5.2 Standards. Ensure non-certified ULDs meet a standard (see Appendix B for suggested standards).

2.4.5.3 Communicate. Inform employees and vendors loading aircrafts converted from passenger to all-cargo by an STC that the aircraft could have different ULD requirements than other STC conversions or production aircraft configurations in the operator’s fleet.

2.4.5.4 Differences. Ensure personnel understand that compatibility, limits, or restrictions may exist between similar aircraft types with STC conversions, and that the aircraft may have been produced as a freighter by a TC holder. The following list details examples of the differences:

2.4.5.4.1 Aircraft weight limits;

2.4.5.4.2 Cargo zone index changes forward/aft body;

2.4.5.4.3 CG limits;

2.4.5.4.4 Forward and aft body structure loading limits;

2.4.5.4.5 Fuel index tables;

2.4.5.4.6 Individual compartment maximum loads;

2.4.5.4.7 Lateral cargo unbalances;

2.4.5 Page 17

2.4.5.4.8 Main deck door opening variances;

2.4.5.4.9 Maximum allowable loads limited by restraint;

2.4.5.4.10 Maximum allowable takeoff weight limits;

2.4.5.4.11 Maximum area load limits;

2.4.5.4.12 Maximum cargo zone load limits, including cumulative loads above and below deck;

2.4.5.4.13 Maximum cumulative loads aft to forward;

2.4.5.4.14 Maximum floor loading limits;

2.4.5.4.15 Maximum ramp weight limits;

2.4.5.4.16 Maximum ULD gross weight restrictions by aircraft position;

2.4.5.4.17 Missing inoperative cargo restraint limits;

2.4.5.4.18 Reduced over wing zone capabilities;

2.4.5.4.19 ULD height restrictions;

2.4.5.4.20 Asymmetrical load limits; and

2.4.5.4.21 Zero fuel weight restrictions.

2.4.5.5 ULD Contour and Dimensions. Compare the size of the main and lower deck compartment door openings with the contour and dimensions of ULDs to be loaded. An operator should take into consideration any height restriction within the aircraft cargo compartments.

2.4.5.6 Approved ULD Limitations. Ensure approved ULD limitations are maintained in the manual. An operator should base these limitations on data from applicable aircraft WBMs or STC supplemental WBMs. The limitations should identify which ULDs are compatible with specific aircrafts, and should also be easily accessible by all affected persons.

NOTE: The limitations section of the AFM or AFM supplement may include information from the aircraft WBM.

2.4.5.7 Authorized ULDs. Ensure its aircraft WBM or other appropriate manual states which ULDs may be carried aboard the aircraft on the main deck or lower lobes. In certain instances, particularly with an aircraft’s lower lobes, certain compartments may be certified to carry bulk or restrained cargo, or both. The WBM or other appropriate manual should identify the ULDs by the type authorized to be carried aboard the aircraft, considering the aircraft and CLS capabilities.

Par 2.4.7 Page 18

2.4.5.8 Use of Non-Certified ULDs. Ensure the operator does not use non-certified ULDs in any compartment of an all-cargo or combination aircraft, unless (1) the ULDs are authorized by aircraft manufacturer or WBM, or (2) tiedown instructions describe how to restrain the ULDs as bulk cargo.

2.4.5.9 Unauthorized Pallet and Net Combinations. Ensure employees and vendors don’t combine incompatible nets and pallets.

2.4.6 Responsibilities for the Maintenance and Repair of ULDs, Pallets, and Nets. ULDs, pallets, and nets must be maintained under an operator’s or vendor/supplier’s maintenance program that satisfies the ICAs of the ULD manufacturer. The operator should have a program to determine the serviceability of the ULD when it is intended to be placed on board the aircraft and ULD traceability through their authorized vendor list which is made available to the FAA.

2.4.7 Responsibilities of an Operator After Purchasing/Leasing a ULD.

2.4.7.1 Certified and Non-Certified ULDs.

2.4.7.1.1 Certified ULDs.

2.4.7.1.1.1 New Certified ULDs. When an operator purchases/leases new certified ULDs, it should perform a first article inspection (see Appendix C, Definitions Related To Air Cargo Operations) of the ULD to confirm its conformance to the type design, and is eligible for installation on the operator’s aircrafts. The equipment manufacturer must show conformity on subsequent deliveries of new ULD equipment.

2.4.7.1.1.2 Used Certified ULDs. When an operator purchases/leases used certified ULDs, it should perform a serviceability inspection, conducted by appropriately trained FAA-certificated personnel, if existing records don’t confirm the ULD’s serviceability. After completing the inspection, the operator issues a tag verifying the serviceability of the ULD before placing it into service. After an initial inspection, the operator should then maintain its own maintenance inspection and repair records for the ULD. If the ULD has appropriate records to verify its serviceability, the operator should perform a receiving inspection in accordance with its procedures.

2.4.7.1.2 Non-Certified ULDs. When purchasing or leasing a new or used non-certified ULDs, the operator should:

2.4.7.1.2.1 Obtain the manufacturer’s current CMMs and illustrated parts list, subsequent manual revisions, service letters, or SBs;

2.4.7.1.2.2 Verify that the manufacturer establishes clearly defined and tested serviceability limits in accordance with IATA, SAE, or ISO standards, or another standard acceptable to the FAA;

2.4.7.1.2.3 Provide a trained, qualified, and authorized person to perform a quality audit of a repair/overhaul facility where the ULDs are repaired/overhauled;