Appendix E APPENDIX E. SUGGESTED STRUCTURAL DATA FOR PASSENGER-TO-CARGO
CONVERSION PROJECT An applicant should submit the following data to the Federal Aviation Administration (FAA) as structural substantiation in support of a passenger-to-cargo conversion project. This list is not all-inclusive, and each project should be individually evaluated to determine if additional data are necessary. The applicant and the approving authority representative should come to an agreement on the necessary data early in the program as part of the certification plan.
NOTE: Documents with an asterisk (*) are required by Title 14 of the Code of Federal Regulations (14 CFR).
E.1 Aircraft Flight Manual (AFM).* Identifies all operating limitations, including operating speeds and door operation, and contains allowable aircraft fuel and cargo loading directly or by reference. Any additional information necessary to safely operate the aircraft should also be provided.
E.2 Aircraft Loading Document.* Describes the types of cargo containers allowed, how the containers are restrained, and loading requirements when latches are missing or broken. This may be contained in the Weight and Balance (W&B) manual. Ensures compatibility of the cargo loading system (CLS) with the cargo conversion. These modifications have often been incorporated independent of each other. In addition, if the use of tiedown fittings is permitted, the tiedown strength and limitation data should be provided.
E.3 Assembly/Installation Drawings.* Details how all parts are assembled and identifies the number and types of fasteners used.
E.4 Cargo Restraint System. Designed for all critical ground, flight, and emergency landing loads. This includes seat tracks, pallet locks, side restraints, and roller trays. The 9G rigid barrier or cargo restraint net, if required, and its attachment, and the fuselage surrounding structure must be analyzed for critical payloads.
E.5 Certification Plan. Lists all steps necessary to complete FAA certification of the modification. At a minimum, the plan should discuss scope of the project, schedule, use of Designated Engineering Representatives (DER), data submittals, and conformity issues.
E.6 Compatibility Evaluation. The applicant evaluates each aircraft to be modified to ensure it is compatible with the Supplemental Type Certificate (STC) modification. The applicant also identifies and evaluates modifications, alterations, or the incorporation of other STCs that change the type design of the aircraft to be modified. The applicant notes and makes accommodations for differences and necessary drawing changes.
E.7 Compliance Checklist. Lists all applicable rules from the certification basis of the modification of the aircraft. Also identifies necessary compliance with outstanding Airworthiness Directives (AD) and the methods of compliance.
E.8 Configuration Deviations.* Lists all nonconformities with their engineering dispositions.
Appendix E
Page 2 E.9 Damage Tolerance Assessment (DTA).* Required for all 14 CFR part 25 post-Amendment-45-certified aircraft. The applicant should create a DTA for pre-Amendment-45 aircraft in support of a supplement to a standard that is required by an AD.
The DTA should evaluate whether an existing principal structural element has been changed or if one has been created by the modification. Fail-safe requirements should be addressed as necessary.
E.10 Decompression Analysis. The substantiation must show that the cargo compartment is designed to withstand the effects of a sudden release of pressure. Consider impact of solid 9G barrier in decompression scenarios (part 25, § 25.365(e); Civil Air Regulations (CAR) 4b.216(c)(4)).
E.11 Design Criteria. A list of design, analysis, and production methodologies, and requirements used in creating the modification.
E.12 Detail Drawings.* There should be a detail drawing for each part manufactured for use in the modification and some means of controlling the source of all vendor-supplied items.
E.13 Door Mechanical Systems. The applicant analyzes the door opening, latching, and locking mechanisms for most critical loads, which should include maximum hydraulic actuator output and possible jam conditions.
E.14 Door Surround Structure. The door surround structure must be analyzed for the redistributed loads resulting from the door cutout. This includes the fuselage skin, doublers, sills, headers, footers, surrounding frames, and longerons/stringers, latches, and their attachments. An analysis of the door and the door hinge should also be included.
E.15 External Loads Analysis.* Should include most critical aircraft weight distribution at both minimum and maximum weights and critical loading throughout the center of gravity (CG) range, including raised vertical CG, and must consider all points within the operating envelope (that is, gust and maneuver). External loads should also include the effects of loads on pallet locks, load impingement on main deck floors by lower deck, unrestrained cargo, and shift in unit load devices (ULD) or bulk load cargo CG locations consistent with pallet approvals and usage.
E.16 Final Documentation. Documentation showing that all structural margins are positive for the critical load case.
E.17 Floors. The floor beams, fuselage frames, and posts/struts should be analyzed for the most critical loading conditions.
E.18 Flutter Substantiation.* A cargo conversion can change the fuselage stiffness or change the mass distribution, which can have an effect on the aircraft’s flutter characteristics, particularly aft cargo doors.
E.19 Functional Check.* Performed to ensure proper operation of the main cargo door. The number of open-close cycles are to be decided upon with the aircraft certification office. The test
Appendix E could include determining the mean time between failure of components, validating the failure modes and effects analyses, and monitoring the wear of latches (§ 25.1301, CAR 4b.601).
E.20 Identification of Supplemental Type Certificate (STC) Team Members. Identify STC team members and DERs whose experience is commensurate with these kinds of projects (that is, external loads, systems safety assessment, finite element modeling, and validation).
E.21 Illustrated Parts Catalog. Catalog of all parts contained in the STC for procurement purposes.
E.22 Installation Instructions. Any installation instructions necessary other than what is listed in the installation drawings. Ensure that there are adequate instructions for the installation of cargo compartment liners and floor panels to minimize the use of a shop practice that may result in blind drilling of holes that could induce damage (double-drilled holes and short-edge margins) to floor beam caps and fuselage frames.
E.23 Instructions for Continuous Airworthiness (ICA). ICAs are a set of instructions as referenced in 14 CFR part 21, § 21.50, Instructions for continued airworthiness and manufacturer’s maintenance manuals having airworthiness limitations sections; and part 25, § 25.1529, Instructions for continued airworthiness, of the regulations that provide information on how to properly maintain a product in an Airworthy condition, including any inspections or other procedures, as necessary, to prevent catastrophic failure of the product. Without acceptable ICAs, a product cannot be maintained in an Airworthy condition. Order 8110.54 provides additional information on the scope of the ICA to be considered as a function of the original design and/or modifications to a transport aircraft.
E.24 Internal Loads Analysis.* Distribution of loads within the affected airframe structure.
Load distribution should be validated.
E.25 Maintenance Instructions.* Continued airworthiness requirements for the inspection program, which includes the frequency and extent of those inspections.
E.26 Maintenance Manual.* Instructions for continued airworthiness of the modifications.
E.27 Master Data List. Lists all process specifications and reports that substantiate the structural strength and damage tolerance of the modification, along with all test reports (that is, flutter, pressurization, finite element method (FEM) validation).
E.28 Master Drawing List.* Controls all drawings and process specifications that define design of the modification.
E.29 Methodology Description. Describes the methodology used to define (1) the barrier load distributions and intensities and distribute the barrier loads to the monocoque, and (2) the ULD load distributions and intensities and distribute the loads to the restraint system components and floor.
E.30 Pressure Test.* The structure must be designed to withstand (limit load) the maximum pressure relief valve setting combined with flight loads (§ 25.365(a), CAR 4b.216(c)(1)), and the
Appendix E
Page 4 maximum relief valve setting omitting other loads times a factor of 1.33 or 1.67, as appropriate (§ 25.365(d), CAR 4b.216(c)(3)). If the modification or conversion involves changes to the pressure barrier, such as a new door installation, it must be pressure tested per § 25.843 or CAR 4b.376.
E.31 Structural Repair Manual. Instructions for repair of the modifications.
E.32 Structural Substantiation.* Positive margins of safety should be shown for all modified structures. Assumptions used in any analysis or test must be consistent with how the loads are applied and the way the structure carries these loads. A margin of safety table should be published for each structural analysis.
E.33 Weight and Balance (W&B) Manual.* Describes aircraft fuel and payload distributions and CG restrictions. Defines applicable ULDs. Provides any other relevant information necessary for the safe operation of the aircraft.
Appendix F APPENDIX F. PASSENGER-TO-CARGO CONVERSIONS SUPPLEMENTAL TYPE
CERTIFICATE DATA PACKAGE FOR SYSTEMS AND EQUIPMENT F.1 An applicant should submit the following information to the Federal Aviation Administration (FAA).
F.1.1 Certification Plan. Helps determine the scope of the conversion project, that is, full passenger-to-cargo conversion, cargo door-only conversion, or smoke detection system-only conversion, and whether supernumeraries are included. A systems description document may have been included in the certification plan, system failure modes, and effects analyses. It is likely that safety analyses were not prepared; you may have to learn about the system based on drawings and diagrams.
F.1.2 Compliance Checklist. Helps determine methods to comply to all applicable Title 14 of the Code of Federal Regulations (14 CFR)/Civil Air Regulations (CAR).
F.1.3 Master Data List/Top Drawing List. Helps link the Supplemental Type Certificate (STC) drawings/reports down to detailed levels.
F.2 Based on, or lacking, the above data, the following areas should be reviewed for the conversions to determine that the modifications are safe:
F.2.1 Cargo Door. Should include:
F.2.1.1 Safety analyses (including any latch/lock/pin failures that could cause door to unlock);
F.2.1.2 Drawings;
F.2.1.3 Wiring qualification (flammability);
F.2.1.4 Wiring diagrams/schematics;
F.2.1.5 Electrical load analysis;
F.2.1.6 Hydraulic components qualification test;
F.2.1.7 System pressure proof/burst test;
F.2.1.8 Any conformity reports (parts, test article, installation);
F.2.1.9 Flammable fluid fire protection;
F.2.1.10 Aircraft Flight Manual (AFM) and limitations;
F.2.1.11 Cargo door opening, closing, and locking mechanisms, including vent door design with its associated power sources (electrical, hydraulics, mechanical), door opening retention system safety during cargo loading, and system isolation during flight; and
Appendix F
Page 2 F.2.1.12 Cargo door warning system and its redundancy features (door control panel and cockpit displays, sensors, placards).
F.2.2 Continued Airworthiness. Maintenance/overhaul manual, flightcrew operating manual, minimum equipment list (MEL), certification maintenance requirements (if required by safety analyses), and any other relevant information for all systems.
F.2.3 Crew Emergency Exit. Interior arrangement drawing and compliance inspection to determine crew accessibility under any cargo loading condition.
F.2.4 Critical Component. Drawings, reports, or issue papers addressing means of protection of critical controls, lines, and equipment in the cargo compartment.
F.2.5 Smoke Barrier. Should include:
F.2.5.1 Drawings/installation;
F.2.5.2 Smoke penetration test plan and report (may be included in the smoke detection system test report);
F.2.5.3 Flight test report; and F.2.5.4 Conformity reports (parts, test article, installation).
F.2.6 Smoke Detection System. Should include:
F.2.6.1 Installation drawings;
F.2.6.2 A test plan and report (including testing in MEL configuration);
F.2.6.3 Wiring qualification (flammability);
F.2.6.4 Wiring diagrams/schematics;
F.2.6.5 Electrical load analysis;
F.2.6.6 Technical Standard Order (TSO)-approved smoke detector (or other testing done for an STC);
F.2.6.7 System control panel qualification and installation;
F.2.6.8 Flight test report;
F.2.6.9 Conformity reports (parts, test article, installation);
F.2.6.10 Failure modes and effects analyses;
F.2.6.11 AFM and limitations; and
Appendix F Page 3 (and 4) F.2.6.12 Compliance inspection to determine cargo interference with fire protection features.
F.2.7 Title 14 CFR Part 121, § 121.583, Carriage of Persons without Compliance with the Passenger-Carrying Requirements of this Part. Data should include exemption approvals from the FAA and interior arrangement drawings. This includes all 14 CFR part 25 regulations applied for carriage of passengers such as emergency egress assist means and escape routes, emergency lighting, emergency exit access, seats, safety harness, oxygen equipment and supply, portable breathing equipment, safety equipment, markings and placards, and compliance inspection.
F.2.8 Ventilation System. The ventilation may have been modified to provide a means to shut off ventilation to the cargo compartment in case of a fire. Data should include:
F.2.8.1 Detailed design/drawings;
F.2.8.2 Wiring diagrams;
F.2.8.3 Electrical load analysis;
F.2.8.4 Safety analyses;
F.2.8.5 AFM and limitations; and F.2.8.6 Cockpit smoke evacuation procedures (may be required).
Appendix G Page 1 (and 2) APPENDIX G. DESIGN CRITERIA FOR OUTWARD OPENING DOORS The following is an excerpt from a Federal Aviation Administration (FAA) Memorandum to the Director of Airworthiness and Technical Standards of the Air Transportation Association of America ATA, dated March 20, 1992 that defined criteria for outward opening doors.
“(1) Indication System:
(a) The indication system must directly monitor the closed, latched, and locked positions.
(b) The indicator should be amber unless it concerns an outward opening door whose opening during takeoff could present an immediate hazard to the aircraft. In that case, the indicator must be red and located in plain view in front of the pilots. An aural warning is also advisable. A display on the master caution/warning system is also acceptable as an indicator. For the purpose of complying with this paragraph, an immediate hazard is defined as significant reduction in controllability, structural damage, or impact with other structures, engines, or controls.
(c) Loss of indication or a false indication of a closed, latched, and locked condition must be improbable.
(d) A warning indication must be provided at the door operator’s station that directly monitors the door latch and lock conditions, unless the operator has a visual indication that the door is fully closed and locked. For example, a vent door that monitors the door locks and can be seen from the operator’s station would meet this requirement.”
“(2) Means to Visually Inspect the Locking Mechanism: There must be a visual means of directly inspecting the locks. Where all locks are tied to a common lock shaft, a means of inspecting the locks at each end may be sufficient to meet this requirement provided no failure condition in the lock shaft would go undetected when viewing the end locks. Viewing latches may be used as an alternate to viewing locks on some installations where there are other compensating features.”
“(3) Means to Prevent Pressurization: All doors must have provisions to prevent initiation of pressurization of the aircraft to an unsafe level if the door is not fully closed, latched, and locked.”
“(4) Lock Strength: Locks must be designed to withstand the maximum output power of the actuators and maximum expected manual operating forces treated as a limit load. Under these conditions, the door must remain closed, latched, and locked.”
“(5) Power Availability: All power to the door must be removed in flight, and it must not be possible for the flightcrew to restore power to the door while in flight.”
Appendix H APPENDIX H. EXAMPLE PROPOSED TIEDOWN SCHEME FOR A SINGLE
SPECIAL CARGO ITEM Proposed tie-down locations for 6 straps
775.0 • FORWARD 1153.0 • FORWARD 1643.0 2012) 22) 23 24(25(20(27 28 29 30 31) 32 33 34) (35 36 37 3 (39 40 41) 42 13) 44) 4546(47 48 49 50) )(52 53) 54 55 56 57) 58) 59(60 61 62 2¼ 34! 84 94 1643) 10Д «I 114 124 ‹ 17Д 18Д 51 6555 19Д - 204 214 26 Д 27 Д Dallat I ca 28Д * 29 Д 30Д 35 Д 36 Д
10) 102 (03 109 145 (06 107 108 109 10) (1) 12) (13 14 115) 16) 17) 18 1 120) 12) 12) 123) (20 (25 20) 127 28 29 13) 3) 1) 33) 3) 35 139 137 138 39 10 11) 142
• Side Guides
• Pallet Locks Center Guides Roller Trays (moveable tie-down rings) • Center Floor (BBL +/-6.5) › Outboard Walkway
775.0 FORWARD 1153.0 + FORWARD 1643.0 )(19 (20) (21) (22) 30) (31) (32) ) (38)(39) (40 (4 64 19 20 21 22 23 24 26 27 ocks 36 37 38 39 40 g 1|42 43 44 45 Pallet ++
84)(85) 86) (87)( (90) (91) 99) (100) (10) • 102 103) 105 109 107 108 109) 110 11) (12 13 119) 115) 119 117 118 119 120) (122 (123) 124 NOTE: This example does not include the complete aircraft load.
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