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).
Page 44 AC 43.13-1A 1972 *B-* WELD GAP $" SIZE OF ROSETTES = 14G. DRILL OUTSIDE
TUBES ONLY B C
SEA-SEE * B- -2A-→ IŁA L = MAXIMUM INSERT LENGTH SAW .08 C OFF OF T.E. AND WELD INSERT TUBE IS OF SAME STREAMLINE TUBING AS ORIGINAL.
A IS E B 8 IS MINOR AXIS LENGTH OF ORIGINAL STREAMLINE TUBE
C IS MAJOR AXIS LENGTH OF ORIGINAL STREAMLINE TUBE S. L. SIZE .382 _ 572 1.340 5.16 1¼ ,476 • 714 1.670 6.43 1/½ . 572 1858 2.005 7.72 1 ¾ .667 1.000 2.339 9.00 2 .763 1.144 2.670 10.30 2 '¼ .858 I.286 3.008 11.58 2 V/½ ,954 1.430 3.342 12.88 FIGURE 2.14.-Streamline tube splice using split insert (applicable to landing gears).
Par 79
kc 43.13-14 1972
c. Axle Assemblies. Representative types of repairable and nonrepairable landing gear axle assemblies are shown in figure 2.16. The types as shown in A, B, and C of this figure are formed from steel tubing and may be repaired by the applicable method shown in figures 2.5 thru 2.15 in this Advisory Circular. However, it will always be necessary to ascertain whether or not the members are heat treated.
The axle assembly as shown in figure
2.16(D) is, in general, of a nonrepairable type for the following reasons:
(1) The axle stub is usually made from a highly heat-treated nickel alloy steel and carefully machined to close tolerances. These stubs are usually replaceable and should be replaced if damaged.
(2) The oleo portion of the structure is generally heat-treated after welding and is perfectly machined to assure proper functioning of the shock absorber. These parts would be istorted by welding after machining.
J. BUILT-UP TUBULAR WING OR TAIL SURFACE ARS. Repair built-up tubular wing or tail surce spars by using any of the applicable plices and methods of repair shown in figures 5 through 2.15 provided the spars are not eat-treated. In the case of heat-treated spars, he entire spar assembly would have to be reeat-treated to the manufacturer's specificaons after completion of the repair. In genal, this will be found less practicable than placing the spar with one furnished by the anufacturer.
WING AND TAIL BRACE STRUTS. In general, 'ill be found advantageous to replace damwing-brace struts made either from ded or streamlined tubing with new mempurchased from the original manufac- However, there is no objection from an rthiness point of view to repairing such ers in a proper manner. An acceptable d, in case streamlined tubing is used, will nd in figure 2.18. Repair similar memnade of round tubes using a standard as shown in figures 2.5, 2.7, or 2.8.
a. Location of Splices. Steel brace struts may be spliced at any point along the length of the strut, provided the splice does not overlap part of an end fitting. The jury strut attachment is not considered an end fitting; therefore, a splice may be made at this point. The repair procedure and workmanship should be such as to minimize distortion due to welding and the necessity for subsequent straightening operations. Observe every repaired strut carefully during initial flights to ascertain that the vibration characteristics of the strut and attaching components are not adversely affected by the repair. A wide range of speed and enginepower combination must be covered during this check.
(1) Fit and Alignment. When making repairs to wing and tail surface brace members, pay particular attention to proper fit and alinement to avoid distortion.
82, REPAIRS TO WELDED PARTS. Repairs to welded assemblies may be made by:
a. Repiacing welded joints-cutting out the welded joint and replacing it with one properly gusseted, or
b. Replacing weld deposit-chipping out the metal deposited by the weld process and rewelding after properly reinforcing the joint by means of inserts or external gussets.
83. STAINLESS STEEL STRUCTURE. Repair structural components made from stainless steel, particularly the "18-8" variety (18 percent chromiun, 8 percent nickel), joined by spot welding in accordance with the instructions furnished by the manufacturer. Substitution of bolted or riveted connections for spot-welded joints are to be specifically approved by an authorized representative of the FAA.
a. Secondary Structural and Nonstructural Elements. Repair such elements as tip-bows or leading and trailing edge tip-strips of wing-andcontrol surfaces by soldering with a 50-50 lead-tin solder or a 60-40 alloy of these metals.
For best results use a flux of phosphoric acid (syrup). Since the purpose of flux is to attack the metal so that the soldering will be effec- Par 79
Page 48 AC 43.13-:
19:
tive, remove excess flux by washing the joint. welded seams in boat hulls, fuel tanks, etc., in Due to the high-heat conductivity of the stain- similar manner.
less steel, use a soldering iron large enough to do the work properly. Repair leaky spot- 84.~94. RESERVED.
Par 83