SD3-60 STRUCTURAL REPAIR MANUAL z SRM 18.0.0.0REPAIRS - GENERAL 1. General This section contains repair schemes for a variety of common structural damage that could occur to many components of the aircraft (ie these repairs are not restricted to any one ATA chapter). Any limitations for the application of these repairs will appear on the repair scheme. Advice on the supporting of the structure/aircraft during repair can be found in Refer to 51-50-00, pb1. 2. Standard Practices A. The cut edges of parts and of drilled holes must be finished to a smooth surface, as follows: (1) Deburr all holes, ensuring that only upset metal around the hole is removed, and that deburring does not damage the surface in any way. Material Thickness Edge Chamfer/Radius Less than 0.125" Min. - 0.005" Max. - 25% of Thickness Over 0.080" 0.015" + or - 0.010" Edge Corner Relief Table 1 (2) Remove sharp corners from edges by radiusing or chamfering the edges. Refer to Table 1. (a) Relieve edges of extrusions using fine cut files, metal scrapers or abrasive paper or cloth. Ensure edges are free from roughness or gouges. (b) Relieve edges of skin panels and skin repair parts using mill files for straight edges and fine cut files for curved edges. If using a fine cut file, use a light draw file technique followed by light sanding with a fine abrasive paper, emery cloth or Scotch Brite pads. (c) The edge finish for aluminium parts must be reasonably smooth and free from nicks or gouges. B. Protective Treatment of Metal parts Any repair process which breaks the surface of original structure requires a protective treatment. The treatment acts as a paint and corrosion inhibiter when applied prior to the installation of repair parts. unclad aluminium alloys or magnesium alloys, of the original structure require subsequent reprotection in cases where repair processes expose considerable area to possible corrosion. Locally made aluminium alloy repair components require pre-assembly surface treatment. This is to comprise of:- Page 1
z SD3-60 STRUCTURAL REPAIR MANUAL - chromic Acid Anodizing (or Alodine/Alocrom 1200, or equivalent). Refer to 51-24-00, pb1. - Epoxy priming. Refer to 51-23-00, pb1. Structural components whose surfaces have been damaged, but not beyond the limits of allowable damage, or whose surfaces have been damaged by corrosion, must be reprotected. NOTE: The following safety precautions should be observed when carrying out chemicallybased protective treatments and cleaning processes. (1) Respirators, goggles, rubber or neoprene gloves, boots and aprons should be worn when preparing chemical solutions and during application of the relevant process. Do not allow chemical powder or solution to contact the skin. if the skin should become contaminated, wash the affected area with clean water immediately. Obtain medical aid if skin irritation occurs. (2) If chemical solution contacts the eyes, wash with clean water followed by a wash with a boric acid solution. Obtain medical aid as soon as possible. 3. Temporary Repair of Adhesive Bonded Assemblies The main fuselage panels are adhesive bonded to corrugated reinforcing inner skins, and temporary repairs to these panels may be carried out to enable the aircraft to return to base for a detailed structural inspection and for replacement of damaged panels. Refer to 53-00-00, pb201. The standard repair schemes in Chapter 53-00-00 relative to fuselage panels can be adapted to suit as temporary repairs. If the rupture of the bonding material is only very local on secondary type structure the use of a suitable cold bonding adhesives is permitted for a temporary repair only. Consultation with Bombardier Aerospace, Aerospace Customer Support is recommended before proceeding with any major repairs. Trailing edges may be repaired on a temporary basis by using a cold bonding adhesive as shown. Refer to 51-72-00, Figure 6. Page 2
SD3-60 STRUCTURAL REPAIR MANUAL z 4. Typical Structural Repairs The following pages contain details of approved repairs of a general nature to the aircraft structure. CAUTION: THESE REPAIRS MAY AFFECT THE FATIGUE CRITICAL BASELINE STRUCTURE. REFER TO 51-00-01 FOR FURTHER INFORMATION ON FCBS AND PROCEDURES TO BE FOLLOWED, PRIOR TO INCORPORATING ANY OF THESE REPAIRS. A. List of approved repairs: - Typical Temporary Repair-Using High Tensile Bolts. Refer to Figure 1. - Typical Skin Patches. Refer to Figure 2. - Typical Repairs for Lightening Holes. Refer to Figure 3. - Typical Stringer Repairs. Refer to Figure 4. - Typical Cracked Stringer Repair. Refer to Figure 5. - Typical Flange and Web Repairs. Refer to Figure 6. - Typical Flange Repairs. Refer to Figure 7. Page 3 Feb 01/10
z SD3-60 STRUCTURAL REPAIR MANUAL Typical Temporary Repair - Using High Tensile Bolts Figure 1 Page 4
SD3-60 STRUCTURAL REPAIR MANUAL z Typical Skin Patches Figure 2 Page 5
z SD3-60 STRUCTURAL REPAIR MANUAL Typical Repairs for Lightning Holes Figure 3 Page 6
SD3-60 STRUCTURAL REPAIR MANUAL z Typical Stringer Repairs Figure 4 Page 7
z SD3-60 STRUCTURAL REPAIR MANUAL Typical Cracked Stringer Repair Figure 5 Page 8
SD3-60 STRUCTURAL REPAIR MANUAL z Typical Flange & Web Repairs Figure 6 Page 9
z SD3-60 STRUCTURAL REPAIR MANUAL Typical Flange Repairs Figure 7 Page 10