Rev. 1977 AC 43.13-2A Chapter 12. LITTER, BERTH, AND CARGO TIEDOWN DEVICE INSTALLATIONS
241. GENERAL. This chapter provides data for and Repair") Commercially available litters or down device installations in airplanes and rotor- making acceptable litter, berth, and cargo tie- installation and load criteria. stretchers may be utilized provided they meet craft. Prior to proceeding with the alteration, determine the airworthiness standards applicable aphragm, or other means at the forward end of Provide a padded end board, canvas dito the contemplated alteration. Refer to the each litter or berth that will withstand the total proper volume of the FAA publication "Type Certificate Data Sheets and Specification" for the litters and berths installed parallel to the air- forward static test load. Safety belts used for certification basis of the aircraft involved. When airworthiness standards pertinent to the airplane craft's longitudinal axis are not required to with- stand forward loads as these loads are to be involved are not available, current airworthiness taken up by the padded end boards.
standards may be used. For example, FAR 23, Design litters or berths intended for adults for 25, 27, or 29, as applicable, may be used in place occupants weighing at least 170 Ibs. In those of CAR 4a, 4b, 6, or 7 or Bulletin 7a. instances where litters or berths are for children,
242. INSTALLATION CONSIDERATIONS. design the installation for the maximum intended weight. See paragraph 247 for placarding.
erated within the weight and center of gravity a. Assure that the altered aircraft can be op- tendants or other passengers that will be carried Provide approved seats for any cabin atranges. Refer to chapter 1, paragraph 9 of this when litters are installed.
handbook. b. Cargo tiedown devices may be assembled
b. Determine that there will be free access to from webbing, nets, rope, cables, fittings, or other all equipment and controls essential to the proper material which conforms to NAS, TSO, AN, operation of the aircraft, required emergency MIL-SPEC, or other acceptable standards. Use exits, and emergency equipment. snaps, hooks, clamps, buckles, or other acceptable
c. Use only materials that are at least flame- fasteners rather than relying upon knots for seresistant for covering of floors, litters, or berths. curing cargo. Install tensioning devices or other Refer to the applicable airworthiness standards means to provide a method of tightening and for the aircraft involved to determine the re- adjusting the restraint system to fit the cargoes quired flame-resistant qualities. For aircraft in to be carried.
Provide covers or guards where necessary to prevent damage to or jamming of the aircraft's equipment, structure, or control cables.
tion of cargo with respect to passengers, cargo 244. STRUCTURAL ATTACHMENT. Commercially compartment, or aisle width. available seat tracks, rails, or other types of
243. FABRICATION AND INSTALLATION. ment, provided they conform to an accepted anchor plates may be used for structural attachtubing, sheet metal, extrusions, canvas, webbing, a. Litters and berths may be fabricated from standard (see chapter 1, paragraph 6). This type of hardware permits a ready means of methods, techniques, and practices. visory Circular 43.13-1A "Acceptable Methods, or other suitable material, using acceptable (Ref. Ad- mounting a wide variety of quick-disconnect fittings for litters, berths, and cargo tiedown. Typical examples of such fittings and their at- Techniques, and Practices-Aircraft Inspection tachment are shown in figures 12.1 through 12.5.
Chap 12 89
AC 43.13-2A Rov. 1977
EXTRUDED TRACK ANCHOR PLATE Light duty Medium duty Heavy duty ces Extruded track and anchor plates are available in several different styles and load capacities and will accommodate a wide variety of quick attachment fittings.
SINGLE PIN TYPE SINGLE PIN TYPE
HOLD DOWN FITTINGS CARGO TIE DOWN FITTINGS Adjustable These types of fittings are suitable for litter or berth attachment to the extruded track and anchor plate styles shown above.
These types of fittings are suitable for cargo tie down attachment to the extruded track and anchor plate styles shown above.
DUAL PIN TYPE CARGO TIE FITTINGS 360° Rotation Low profile n These types of cargo tie down fittings are of greater capacity than the single pin types and are suitable for use with the extruded track style shown above.
FIGURE 12.1. Extruded track, anchor plates, and associated fittings.
90 Chap. 12
Rev. 1977 AC 43.13-2A
PAN FITTINGS SINGLE STUD FITTINGS Stud & Cargo ring Cargo ring only Stud only Round head Hex head
SINGLE STUD CARGO TIE DOWN FITTING
SINGLE STUD HOLD DOWN FITTINGS Lift to release These types of fittings are suitable for cargo tie down attachment to the single stud fittings or stud equipped pan fittings shown above.
STUD/RING These types of fittings are suitable for litter or berth attachment to the single stud fittings or stud equipped pan fittings shown above.
EYE BOLT These types of fittings are suitable for litter, berth, and/or cargo tie down attachment directly to the aircraft structure.
FIGURE 12.2. Miscellaneous litter, berth, and cargo tiedown fittings.
Chap 12 91
AC 43.13-2A Rev. 1977 A. Attachment method utilizing a honeycomb doubler.
Single Studs or Eye Bolts.
Pan Fittings.
B. Attachment methods utilizing reinforcing plates.
Stud/Rings.
1. Bed all inserts and spacers in a suitable potting compound.
2. Reinforcing plate.
3. Where fitting is subject to rotation, place washers on both sides and use a positive safety means.
4. (Alternate method in lieu of spacers) Undercut honeycomb, inject potting compound, and drill through when set.
5. Countersink if required for clearance or if desired for appearance.
6. Undercut all open edges of honeycomb 1/16" and seal with potting compound.
7. Honeycomb doubler.
8. Use epoxy or other suitable adhesive to attach doubler and reinforcing plates.
FIGURE 12.3. Typical attachment of fittings to honeycomb structures.
92 Chap 12
Rev. 1977 AC 43.13-2A
EXTRUDED TRACK, · > FLOOR BEAM (Reinforce cut out as neccessary to retain strength.)
UNDERFLOOR REINFORCEMENT
FLOOR BEAM DOUBLER/ATTACH ANGLE FIGURE 12.4. Installation of underfloor support for extruded track.
Chap 12 93
AC 43.13-2A Rev. 1977
THREE BAR TYPE SLIDE Rigging for easiest adjustment and moderate loads.
applicable When Rigging for maximum load whether slide is joggled or not.
TYPICAL NAS STRAP ASSEMBLY Available with various types of end hardware and up to 5000 capacity.
TENSIONING SLIDE Used to preload cargo tie down straps.
Handhold
CARGO BARRIER NET
CARGO TIE DOWN NET Commonly used to restrain bulky or composite cargo.
Chap 12 FIGURE 12.5. Typical cargo tiedown straps and cargo nets.
Rov. 1977 AC 43.13-2A office. The addresses of T.C. holders and FAA controlling regions are given in the FAA publication Type Certificate Data Sheets and Specifipacity. cations."
cial operations.
board configuration.
tested TO the criucal ultimate load factor. Refer to chapter 1 of this handbook for computation and testing procedures.
Chap 12 95
AC 43.13-2A When the cargo compartment is separated from the cockpit by a bulkhead that is capable of withstanding the inertia forces of emergency conditions a forward load factor of 4.5g. may be All other applications require the use of a 9g. forward load factor.
Each cargo tiedown fitting installation must be static tested under forward, side, and up load conditions. Individual fittings may be tested by applying a single pull of 12.6g. forward load at an angle of 18.5° up and 9.5° to the left or right, as applicable, of the aircraft longitudinal axis.
For example, assuming a 5,000 pound static pull (rating of a typical tiedown fitting) is applied as described and divided by the g. load factor we find the fitting installation will be capable of restraining a 397 pound load under emergency conditions.
9.5g. x 1.33 Apply 5,000 lb. pull 18.5° 9.5g. x 1.33 = 12.6g. 5,000 lb. - =397 1b.
9g. 12.6g.
1.5g.
9.18- 9.30 9g When a cargo-restraining net or cargo container with multiple attachments is used the static load requirements for each tiedown fitting may be divided equally between the fittings. For example, assume that the maximum cargo load to be carried is 1,800 pounds and 10 tiedown fittings are to be used, the static load requirement for each fitting is approximately 2,155 Ibs.
9g. x 1.33 x 1,800 10s.
=2154.6 Ibs.
10 fittings Placard individual tiedowns for the maximum weight to be secured.
247. OPERATING LIMITATIONS, LOADING IN- STRUCTIONS, AND PLACARDS. Prepare revisions or supplements to the aircraft's Flight Manual 96 Rev. 1977 or operating limitations, weight and balance records, and equipment list changes as necessitated by the installation of the litter, berth, or cargo tiedown systems.
NoTE.-Revisions or supplements to the approved portions of the aircraft's Flight Manual markings, placards, or other operating limitations require FAA engineering approval. Submit the requested changes and supporting data to the local FAA Flight Standards Office for review and processing.
Provide instructions covering the installation and use of the litter or cargo restraint systems.
For aircraft which require a Flight Manual, incorporate these instructions as a supplement.
On other aircraft, provide a placard which references the appropriate instruction. In the instructions, cover such items as removal and reinstallation of seats or other equipment exchanged for litters or cargo restraint systems, use of cargo nets, barrier nets, number and positioning of tiedown straps, maximum load for each compartment or tiedown area, permissible load per square foot, number of tiedown points allowable per foot of track, and maximum height of the load's center of gravity above the floor.
a. Cargo Area Placards. Install placards or other permanent markings to indicate the maximum allowable cargo load and weight per square foot limitation for each cargo area. Placard seat tracks as to number of tiedown points permissible per foot of track. Attach a permanent lable or other marking on each cargo net, barrier net, and at cargo tiedowns to indicate the maximum cargo weight that the net or attachment will restrain when installed according to the loading instructions.
b. Litter and Berth Placards. Install a placard or other permanent marking on each litter or berth indicating its permissible direction of installation (forward, aft, or side-facing), passenger weight limitation (if less than 170 lbs.), and whether or not the litter or berth may be occupied during takeoffs and landings.
248.-260. [RESERVED] Chap 12
Rev. 1977 AC 43.13-2A Chapter. 13. PENETRATION THROUGH PRESSURIZED STRUCTURE Section 1. ELECTRICAL WIRE BUNDLES AND COAXIAL CABLE FEED THROUGH PRESSURIZED STRUCTURE
261. GENERAL. This section describes typical methods for sealing openings where wires and coaxial cable are installed through pressurized structure.
a. Assure that the strength of the structure is maintained when installations require additional
b. The aircraft manufacturer's data may specify the size and location where additional openings are permitted and the reinforcement required to maintain the design strength of the affected
c. The manufacturer's data may also recommend the specific sealant to be used and provide instructions for the application.
Caution: Sealant and solvents may contain toxic and/or flammable components. Avoid inhalation of vapors and supply adequate ventilation. Wear appropriate respiratory protection while using these materials in con fined areas. Avoid contact with the skin and
262. CLEANING. Use a cleaning solvent and clean a larger area than required for the fair-lead or connector. Remove solvent by blasting with dry air and wiping with a clean soft cloth.
263. APPLICATION OF SEALANT. Seal electrical wire bundles and connectors where they pass through the opening in the pressurized structure.
a. Separate and coat each wire with sealant over the length which is to pass through the fairlead, fig. 13.1A. After coating each wire with sealant, pull the wire bundle into position in the fair-lead, fig. 13.1B. Assure that the fair-lead is located on the pressure side of the structure.
b. Apply sealant to the surface of the fair-lead which comes in contact with the pressurized structure. Use a spatula or brush and spread sealant on the entire surface approximately ⅓2-inch in thickness. Attach the fair-lead to the pressurized structure, sealant, sealant should extrude around the mounting flange (see fig. 13.1C).
c. Wrap the fair-lead with at least three turns of masking tape as shown in fig. 13.1D.
Puncture the masking tape over the injection hole in the fair-lead assembly and inject sealant with a sealing gun. Apply sealant over each fairlead fastener as shown in fig. 13.1E.
d. Complete all of the aforementioned steps during the application time of the sealant. Allow sealant to cure, remove masking tape and excess sealant which extruded from the fair-lead mounting flange.
e. Figures 13.2 and 13.3 illustrate a different type fair-lead and wire bundle connector. The procedure for sealant application is the same as previously described.
f. Figure 13.4 illustrates various coaxial connectors frequently used for installation through structure. Fair-leads are not recommended for installation of coaxial cable. Sealant application is the same as previously described.
264.-290. [RESERVED] Chap 13 97
Rev. 1977 AC 43.13-2A
- EXTRUDING
SEALANT
WIRE BUNDLE,
SEALANT
WIRE BUNDLE
SEALANT
EXTRUDING
SEALANT FIGURE 13.2 Fair-lead feed through.
— EXTRUDING
SEALANT FIGURE 13.3 Typical connector.
Chap 13 99
Rev. 1977 AC 43.13-2A Appendix 1 CROSS REFERENCE TABLE OF PARAGRAPH NUMBER CHANGES FROM AC 43.13-2 DATED 1965 Former Paragraph Revised Paragraph Former Paragraph Revised Paragraph 1 1 57 68 2 2 58 69 70 [Reserved] 74 75 76-78 [Reserved] 79 80 13-20 [Reserved] [Reserved] 66 81 67-70 [Reserved] 82-85 [Reserved] 71 76 [Reserved] 77-80 [Reserved] 92-95 [Reserved] 29-35 [Reserved] 105 106 [Reserved] [Reserved] 107-110 [Reserved] 111 112 94 113 95 114 96-100 [Reserved] 115-120 [Reserved] 47-50 [Reserved] 57-60 [Reserved] 101 121 102 122 61 103 123 124-125 [Reserved] 101 126 105 127 [Reserved] 106 128 107 129 108 130