ever, the best method to use on such materials as stainless steels, magnesium, and aluminum alloys because of base metal oxidization, distortion, and loss of ductility.
NoTE: When oxyacetylene is used, all flux must be removed, as it may cause corrosion.
b. Accurately Identify the Type of Material to be Repaired. Reference to chapter 7 may provide this information. If positive identification is not possible, contact the aircraft manufacturer or subject the item to a metallurgical laboratory analysis. Before any welding is attempted, carefully consider the weldability of the alloy since all alloys are not readily weldable. The following steels are readily weldable: plain carbon of the 1000 series, nickel steel of the SAE 2800 series, chrome-nickel alloys of the SAE 8100 series, chrome-molybdenum steels of the SAF 4100 series, and low nickel-chromemolybdenum steel of the SAL 8600 series.
c. Preparation for Welding. Hold elements to be welded in a welding jig or fixture which is sufficiently rigid to prevent misalinement due to expansion and contraction of the heated material and which positively and accurately position the pieces to be welded.
d. Cleaning Prior to Welding. Clean parts to be welded with a wire brush or other suitable methods. When cleaning with a wire brush, do not use a brush of dissimilar metal; for example, brass or bronze on steel. The small deposit left by a brass or bronze brush will materially weaken the weld and may cause cracking or subsequent failure of the weld. In case members were metallized, the surface metal may be removed by careful sandblasting followed by a light buffing with emery cloth.
•. Condition of Complete Weld. Make sure that:
(1) The finished weld has a smooth seam and is uniform in thickness;
(2) The weld metal is tapered smoothly into the base metal;
(3) No oxide has formed on the base metal at a distance of more than 1/2 inch from the weld;
Par 60 AC 43.13-1 197
(4) The weld shows no signs of blowholes porosity, or projecting globules;
(5) The base metal shows no signs of pit ting, burning, cracking, or distortion;
(6) The depth of penetration insures fusion of base metal and filler rod; and
(7) Welding scale is removed by wire brush ing or sandblasting.
f. Practices to Guard Against. Do not file weldi in an effort to make a smooth-appearing job, a such treatment causes a loss of strength. D not fill welds with solder, brazing metal, ol any other filler. When it is necessary to rewel a joint which was previously welded, remov all old weld material before rewelding. Avoic welding over a weld because reheating may cause the material to lose its strength and be come brittle. Never weld a joint which hai been previously brazed.
g. Torch Size (Oxyacetylene Welding). The sizi of the torch tip depends upon the thickness of the material to be welded. Commonly user sizes proved satisfactory by experience are:
Thickness of steel Diameter of Drill size (in Inches) hole in tip
0.015 to 0.031 0.026 71
0.031 to 0.065 .031 68
0.065 to 0.125 .037 63
0.125 to 0.188 .042 58
0.188 to 0.250 .055 Б4
0.250 to 0.875 .067 51
h. Welding Rods and Electrodes. Use weldin rods and electrodes that are compatible wit the materials to be welded. Welding rods anc electrodes for various applications have special properties suitable for the application intended. Figure 2.8 shows the allowable strength for the weld metal. Figure 2.2 lists specifications for corresponding metals, ar the applicable specification will identify t use of A.C. or D.C., straight or reverse polal
1. Rosette Welds. Rosette welds are generali employed to fuse an inner reinforcing tube (liner) with the outer member. Where a ro sette weld is used, drill the hole, in the outside tube only, of a sufficient size to insure fusion o Chap
FIGURE 2.2.-Specifications guide for welding metals.
Material To Electrie Tungaten Inert Metal Inert Shield Be Welded Welding Gas (TIG) Ga• (HIG) Carbon ARC Acetviene Medium & High MIL-1-22200/1 MIL-E-29765/1B MIL-E-23765/1B MIL-R-908A Tensile Steel. MIL-9018 Class Class NONE Class 1 Stress Relieved MIL-E-705-2 MIL-E-705-4 High Carbon Steel MIL-E-7018 MIL-E-23765/1B MIL-D-23765/1B MIL-R-CUS1-A MIL-R-908A MIL-E-22200 Class Class Class 1 MIL-E-705-2 MIL-E-705-6 Low and Medium MIL-E-15599-C: MIL-E-23765/1B MIL-E-23765/1B MIL-R-CUSI-A Carbon Steel Class Class MIL-R-5632 MIL-E-705-2 MIL-E-705-6 Class 1 Aluminum and MIL-E-15997A QQR-566 QQR-566 QQR-566° QQR-566 * Aluminum Alloy MIL-E-16053-K' MIL-E-16053-K' Stainless Alloys MIL-E-6844 MIL-R-5031B' MIL-R-5031B* MIL-R-5081B* MIL-R-5081B* M-L-E-22200• Copper and Nickel NONE QQR-571A * MIL-E-21659* QQR-571A * QQR-571A • Alloys Magnesium NONE MIL-R-6944 MIL-W-18326 NONE MIL-R-6944 Alloys Specify Alloy Specify Alloy Specify Alloy Hard Surface MIL-E-19141 MIL-E-19141 MIL-E-19141 MIL-E-19141 MIL-19141 Filler (Refer to A.W.S (Refer to A.W.S (Refer to A.W.S. (Refer to A.W.S. (Refer to A.W.S.
A5.18 or ASTM-A899) А5.18 or А5.18 ог Аб.13 ог Аб.18 от ASTM-A399) ASTM-A399) ASTM-A899) ASTM-A899) ' Specify MIL Type 6010, 6011, 6012, 6013, 6020, 6024, 6027-Same as A.W.S. Number for type. A.W.S. American Welding Society * Specify Aluminum Alloy by Aluminum Assoc. Number e.g.: Type 1100, 5083, etc. ASTM American Society for Testing Materials
• Specify Alloy by A.IS.I. Number e.g.: 304, 316, 842, etc. A.I.S.I.. American Iron and Steel Institute (SAE).
* Specify type per A.W.S. A5.6-66 or ASTM B-225-66.
Page 32 AC 43.13-14 197" FIGURE 2.3.-Strengths of welded joints.
Materle! Heat treatment Welding rod Ultimate Ultimate subsequent to or electrode atress 11 tenaile welding shear × 1000 atresa X 1000 Carbon and MIL-R-5632, Class I 82 51 Alloy steels None MIL-E-15599, Classes E-6010 & E-6013 32 61 Alloy steels None MIL-R-5632, Class 2 48 72 Alloy steels Stress relieved MIL-E-6848, Class 10018 50 85 MIL-E-18088, Class E-10015 & E-10016 Alloy steels Stress relieved MIL-E-18038, Class 60 100 E-12015 & E-12016 the inner tube. A hole diameter of approximately one-fourth the tube diameter of the outer tube serves adequately for this purpose.
In cases of tight-fitting sleeves or inner liners, the rosettes may be omitted.
I. Heat-Treated Members. Certain structural parts may be heat-treated and therefore could require special handling. In general, the more responsive an alloy steel is to heat treatment, the less suitable it is for welding because of its tendency to become brittle and lose its ductility in the welded area. Weld the members which depend on heat treatment for their original physical properties, using a welding rod suitable for producing heat-treated values comparable to those of the original members (see paragraph 68h). After welding, reheat-treat such members to the manufacturer's specifica-
69. STEEL PARTS NOT TO BE WELDED.
a. Brace Wires and Cables. Do not weld airplane parts whose proper function depends upon strength properties developed by coldworking. Among parts in this classification are streamlined wires and cables.
b. Brazed and Soldered Parts. Do not weld brazed or soldered parts as the brazing mixture or solder will penetrate the hot steel and weaken it.
c. Alloy Steel Parts. Do not weld alloy steel parts such as aircraft bolts, turnbuckle ends, etc., which have been heat-treated to improve their mechanical properties.
Par 68
70. REPAIR OF TUBULAR MEMBERS.
a. Inspection. Prior to repairing tubular members, carefully examine the structure surrounding any visible damage to insure that n secondary damage remains undetected. Second.
ary damage may be produced in some structur remote from the location of the primary dam age by the transmission of the damaging loa along the tube. Damage of this nature usuall occurs where the most abrupt change in dire tion of load travel is experienced. If this dam.
age remains undetected, subsequent norma loads may cause failure of the part.
b. Location and Alinement of Welds. Unles otherwise noted, welded steel tubing may spliced or repaired at any joint along the leng of the tube. Pay particular attention to th proper fit and alinement to avoid distortion.
6. Members Dented at a Cluster. Repair der at a steel-tube cluster-joint by welding a sp cially formed steel patch plate over the dented area and surrounding tubes, as shown in figure
2.4. To prepare the patch plate, cut a section of steel sheet of the same material and thickne as the heaviest tube damaged. Trim the re forcement plate so that the fingers extend o the tubes a minimum of 1.5 times the resp tive tube diameter as shown in the figu Remove all the existing finish on the damag cluster-joint area to be covered by the reinfor ment plate. The reinforcement plate may formed before any welding is attempted, or may be cut and tack-welded to one or more the tubes in the cluster-joint, then heated ar Chap
AC 43.13-1A Page 33 1972 LONGERON DENTED AT A STATION.
Lite 706
THICKNESS OF PATCH-PLATE
SAME AS LONGERON
THICKNESS, PATCH-PLATE BEFORE FORMING AND WELDING.
PATCH-PLATE FORMED AND WELDED TO TUBES.
FIOURE 2.4.-Members dented at a cluater.
Chap 2 Par 70
Page 34 AC 43.13-1 197 DENTED OR BENT TUBE.
CRACKED TUBE
REINFORCEMENT TUBE SPLIT NOTE:
LOCALLY DENTED OR
TINES MEMBERORSHOULD 15811 IN CLAMP.
REINFORCEMENT LEAST THE SAME GAUGE AS TUBE BEING REPAIRED.
WELD
AS ALTERNATIVE TO SPLIT
A TWO PIECE REIN- FORCEMENT ‚MAY
FORMED FROM STEEL
SHEET OF THE SAME MAT-
ERIAL AND AT LEAST THE
SAME GAUGE AS AGED TUBE FOUR ENDS AND THE DAM- ROSETTE WELDS AS SHOWN.
FIGURE 2.0.-Members dented in a bay--repairs by welded sleeve.
Par 70 Chap
AC 43.13-1A 1972 formed around the joint to produce a smooth contour. Apply sufficient heat to the plate while forming so that there is generally a gap of no more than 1/16 inch from the contour of the joint to the plate. In this operation avoid unnecessary heating, and exercise care to prevent damage at the point of the angle formed by any two adjacent fingers of the plate. After the plate is formed and tack-welded to the clusterjoint, weld all the plate edges to the clusterjoint.
d. Members Dented in a Bay. Repair dented, bent, cracked, or otherwise damaged tubular members by using a split-sleeve reinforcement;
carefully straighten the damaged member; and in the case of cracks, drill No. 40 (0.098) stopholes at the ends of the crack.
71. REPAIR BY WELDED SLEEVE. This repair is outlined in figure 2.5. Select a length of steel tube sleeve having an inside diameter approximately equal to the outside diameter of the damaged tube and of the same material, and at least the same wall thickness. Diagonally cut Ithe sleeve reinforcement at a 30° angle on both ends so that the minimum distance of the sleeve from the edge of the crack or dent is not less than 11/2 times the diameter of the damaged tube. Cut through the entire length of the reinforcement sleeve, and separate the halfections of the sleeve. Clamp the two sleeve sections to the proper positions on the affected reas of the original tube. Weld the reinforce- Page 35 ment sleeve along the length of the two sides, and weld both ends of the sleeve to the damaged tube as shown in the figure. The filling of dents or cracks with welding rod in lieu of reinforcing the member is not acceptable.
72. REPAIR BY BOLTED SLEEVE, Do not use bolted sleeve repairs on welded steel tube structure unless specifically authorized by the manufacturer or the FAA. The tube area removed by the boltholes in this types of repair may prove critical.
73. WELDED-PATCH REPAIR. Dents or holes in tubing may be repaired by a welded patch of the same material and one gauge thicker, as shown in figure 2.6 provided:
a. Dented Tubing.
(1) Dents are not deeper than 1/10 of tube diameter, do not involve more than 1/4 of the tube circumference, and are not longer than tube diameter.
(2) Dents are free from cracks, abrasions, and sharp corners.
(3) The dented tubing can be substantially reformed without cracking before application of the patch.
b. Punctured Tubing. Holes are not longer than tube diameter and involve not more than 1/4 of tube circumference.
* TUBE CIRCUM. -NOT GREATER THAN "A" (MAX.)
• 2A -
- DAMAGE FIGURE 2.6.-Welded patch repair.
Chap 2 Far 70
AC 43.13-14 1971 ALLOW 1/8" GAP BETWEEN ORIGINAL AND ROSETTE WELD REPLAGEMENT TUBES FOR WELDING.
INSIDE
ORIGINAL TUBE ISLEEVE TUBE
- UZA
REPLACEMENT TUBE
ROSETTE WELD FORVIPELVISAP
INSIDE SLEEVE TUBE
ORIGINAL TUBE FIGURE 2.7.-Splicing by inner sleeve method.
74. SPLICING TUBING BY INNER SLEEVE METHOD.
If the damage to a structural tube is such that a partial replacement of the tube is necessary, the inner sleeve splice shown in figure 2.7 is recommended, especially where a smooth tube surface is desired. Make a diagonal cut when removing the damaged portion of the tube and remove the burr from the edges of the cut by filing or similar means. Diagonally cut a replacement steel tube of the same material and diameter, and at least the same wall thickness, to match the length of the removed portion of the damaged tube. At each end of the replacement tube allow a 1/8-inch gap from the diago- Par 74 nal cuts to the stubs of the original tube. Select a length of steel tubing of the same material, and at least the same wall thickness, and of an outside diameter, equal to the inside diameter of the damaged tube. Fit this innersleeve tube material snugly within the original tube, wit a maximum diameter difference of 1/16 inc From this inner-sleeve tube material cut 2 se tions of tubing, each of such a length that th ends of the inner sleeve will be a minimum dis tance of 1 1/2-tube diameters from the neares end of the diagonal cut.
If the inner sleeve fits very tightly in the replacement tube, chill the sleeve with dry ice or Chap 3
I€ 43.13-1A Page 37 972 ,30° SLEEVE
ROSETTE WELDS MAY - WELD
BE OMITTED WHEN SLEEVES FIT TIGHTLY.
- REPLAGEMENT TUBE
ORIGINAL TUBE
FISH-MOUTH SLEEVE
- UZA
ROSETTE WELDS MAY WELD
BE OMITTED WHEN SLEEVES FIT TIGHTLY.
LREPLACEMENT TUBE
ORIGINAL TUBE
FOUR ROSETTE - WELD HERE FIRST WELDS
ORIGINAL TUBE -1/8" GAP
FOR WELDING ALTERNATIVE SPLIT SLEEVE SPLICE ~
IF OUTSIDE DIAMETER OF ORIGINAL TUBE IS LESS THAN I INCH, SPLIT SLEEVE MAY BE MADE FROM STEEL TUBE OR SHEET STEEL. USE SAME
MATERIAL OF AT LEAST THE SAME GAUGE, FOR ORIGINAL TUBE DIAMETERS OF 1 INCH AND OVER, USE SHEET STEEL ONLY.
FIGURE 2.8.-Splicing by outer sleeve method-replacement by welded outside sleeve.
Par 74
in cold water. If this is insufficient, polish down the diameter of the sleeve with emery cloth. Weld the inner sleeve to the tube stubs through the 1/8-inch gap, forming a weld bead over the gap.
75. SPLICING TUBING BY OUTER SLEEVE METHOD.
If partial replacement of a tube is necessary, make the outer sleeve splice using a replacement tube of the same diameter. Since the outer sleeve splice requires the greatest amount of welding, it should be used only when the other splicing methods are not suitable. Information on the replacement by use of the welded outside sleeve method is given in figures 2.8 and 2.9.
Remove the damaged section of a tube utilizing a 90° cut. Cut a replacement steel tube of the same material, diameter, and at least the same wall thickness to match the length of the removed portion of the damaged tube. This replacement tube must bear against the stubs of the original tube with a total tolerance not to AC 43.13- 19 exceed 1/82 inch. The outer sleeve tube mat rial selected must be of the same material an at least the same wall thickness as the origin tube. The clearance between inside diameter c the sleeve and the outside diameter of the orig inal tube may not exceed 1/16 inch. From thi outer sleeve tube material, cut diagonally (o fishmouth) 2 sections of tubing, each of suc length that the nearest end of the outer sleev is a minimum distance of 1 1/2-tube diameter from the end of the cut on the original tube Use a fishmouth sleeve wherever possible. Re move the burr from the edges of the sleeves replacement tube, and the original tube stubs Slip the two sleeves over the replacement tube aline the replacement tube with the origina tube stubs, and slip the sleeves out over thi center of each joint. Adjust the sleeves to sui the area and to provide maximum reinforce ment. Tackweld the two sleeves to the replace ment tube in two places before welding. Apply a uniform weld around both ends of one of the reinforcement sleeves and allow the weld t cool; then, weld around both ends of the r < ORIGINAL TUBE
SLEEVE SLEEVE
TUBE TUBE
ROSETTE ORIGINAL TUBE WELD WELD ORIGINAL TUBE 1/2 A SLEEVE Ve" GAF ALLOW REPLACEMENT TUBE SLEEVE TUBE
TUBE BETWEEN SLEEVES
FOR WELDING, FIGURE 2.9.-Tube replacement at a station by welded outer sleeves.
Far 74
АС 43.73-1А Page 41 1972
WELD SPACER APPROXIMATELY "A" LONG WELDED ON
INSIDE TUBE
•ЗА~ (А) (B) GENERAL NOTE:-
ALL ROSETTE WELDS (C) TO BE & DIAMETER OF THE ORIGINAL TUBES.
GAP 1" (D) FIGURE 2.11.-Repairs at built-in fuselage fittings.
Par 79
Page 42 АС 43.13-1А 1972 GAP I" 30 WELD mh ABC
FORM INSIDE TUBE TO FIT. AT LEAST - 3C - AT LEAST
A - SLOT WIDTH (ORIGINAL TUBE) 8 - OUTSIDE DIAMETER (INSERT TUBE)
C - STREAMLINE TUBE LENGTH OF MAJOR AXIS S.L. SIZE D 9/16 1.340" • 496" 1- 4 11/16 1.670 • 619 1-2 2.005 . 743 1- 4 2.339 .867 2 2,670 991 2-¼ 3.008 1.115 г- ½ ı- ₴ 3.342 1.239
ROUND INSERT TUBE (B) SHOULD BE AT LEAST OF SAME
MATERIAL AND ONE GAUGE THICKER THAN ORIGINAL STREAMLINE TUBE (C).
FIGURE 2.12.-Streamline tube splice using round tube (applicable to landing gears).
Par 79
1972 AC 43.13-TA
OPEN OUT OPEN OUT TO FIT ORIGIN ORIGINAL TUBE AND WELD.
OUTSIDE SLEEVE MAY BE OF SAME SL. TUBING AS ORIGINAL OR USE AT LEAST S.L. TUBING OF AT LEAST THE C- SAME GAUGE.
AT LEAST WELD
A - MINIMUM LENGTH OF SLEEVE 9- STREAMLINE TUBE LENGTH OF MINOR AXIS
- STREAMLINE TUBE LENGTH Of MAJOR AXIS S. L. SIZE
7.324" .572" 1.340" 1-¼ 9.128 .714 1.670 1-½ 10.960 .858 2.005 1- ¾ 12.784 1.000 2.339 2 14.594 1.144 2.670 2-4% 16.442 1.286 3.008 2 - ½ 18.268 1.430 3.342 FIGURE 2.13.—Streamline tube splice using split aleeve (applicable to wing and tail surface brace struts and other members).