Sources: FAA-H-8083-31B metallic structures chapters, and AC 43.13-1B for acceptable practice where nothing more specific applies. Both public domain. Pointers only.
Chapter and section verified against FAA-H-8083-31B and FAA-H-8083-30B, 2023 editions, on 28 August 2026. Page numbers are deliberately not cited: they move between printings. Checked by our handbook citation check against our index of the handbook's chapters and sections.
AC 43.13-1B is cited by chapter, section and paragraph. It is an advisory circular, not a handbook: its paragraph numbers — 11-85, 11-187 — are stable identifiers rather than page references, which is why they are cited and why our handbook citation check does not treat them as pages. Verified against the FAA's copy on 28 August 2026.
| Elements | The ACS asks for | In the source | Where in FAA-H-8083-31B | Where in FAA-H-8083-30B | Where in AC 43.13-1B | What it does not give you |
|---|---|---|---|---|---|---|
K1, K2 |
Inspection and testing of metal structures; sheet metal defect types | Defect types and detection | Ch. 4 — Inspection of Damage; Types of Damage & Defects; Classification of Damage; Assessment of Damage; Inspection of Riveted Joints | — | Ch. 4 — Section 1. Identification Of Metals; Section 2. Testing Of Metals | GEN-K Concepts §1 — which method finds which defect |
K3, K17, S3 |
Repair material selection; structure types | Alloys, tempers, structure classifications | Ch. 4 — Repair Material Selection; Sheet Metal Structure; Aluminum Alloys · Ch. 1 — Truss-Type; Monocoque Type; Semimonocoque Type; Major Structural Stresses | — | Ch. 4 — Section 1. Identification Of Metals; Section 4. Metal Repair Procedures | Temper is invisible. GEN-E Concepts §5 |
K4, K7, K8, S7, S11 |
Layout, forming and drilling; rivet layout; rivet removal and installation | Layout methods, edge distance, pitch, drilling and removal | Ch. 4 — Layout & Forming; Repair Parts Layout; Rivet Spacing & Edge Distance; Edge Distance; Hole Drilling; Installation of Rivets; Removal of Rivets | — | — | Why the pattern arithmetic is what it is. AF-A Concepts §2 |
K5 |
Rivet, hardware and fastener selection | Rivet types, codes, sizing rules | Ch. 4 — Rivet Selection; Solid Shank Rivet; Blind Rivets; Sheet Metal Fasteners | — | — | — |
K6 |
Heat treatment of aluminum | Tempers, solution treatment, aging | Not in this handbook | Ch. 7 — Heat-Treatment of Nonferrous Metals; Solution Heat-Treatment; Precipitation Heat-Treating; Annealing of Aluminum Alloys | — | — |
K9, R2, R3 |
Safety practices; PPE | Shop practice | Ch. 5 — Welding Safety Equipment; Safety Equipment | Ch. 1 — Shop Safety; Safety Around Machine Tools | — | — |
K10–K16, R4, R5 |
Welding — gases, storage, flame and inert-gas practice, shielding gases, steel tube repairs, weld repair procedures; compressed gas bottles; electric welding equipment | All of it | Ch. 5 — Gas Welding; Welding Gases; Gas Cylinders; Neutral Flame; Carburizing Flame; Oxidizing Flame; Gas Tungsten Arc Welding (GTAW); Gas Metal Arc Welding (GMAW); Characteristics of a Good Weld | — | Ch. 4 — Section 5. Welding And Brazing; Section 6. Welding And Brazing Safety | No skill element requires you to weld. AF-A Concepts §1 |
S5 |
Design a repair from a structural repair manual | — | — | — | — | The SRM is the object of the skill |
S14 |
Determine extent of damage and repairability | — | Ch. 4 — Assessment of Damage; Classification of Damage; Negligible Damage; Repairability of Sheet Metal Structure | — | — | The unit's central judgment. AF-A Concepts §5 |
R1 |
Selection of repair materials | Alloy and temper selection, and when substitution is permitted | Ch. 4 — Repair Material Selection | Ch. 7 — Substitution of Aircraft Metals; Standards and Specifications | Ch. 4 — Section 1. Identification Of Metals; Section 4. Metal Repair Procedures | Substitution is not yours to judge. The SRM or other approved data names the alloy and temper; matching by appearance is how a repair becomes unairworthy |
S4 |
Select and install special purpose fasteners | Fastener families, their uses and installation | Ch. 4 — Special Purpose Fasteners; Sheet Metal Fasteners; Reusable Sheet Metal Fasteners | — | — | Which fastener this repair calls for — that is the approved data |
S9, S10 |
Trim and form sheet metal to fit a prepared area; fabricate an aluminum part from a drawing | Layout, flat pattern development, bend allowance, hand forming | Ch. 4 — Layout & Forming; Layout or Flat Pattern Development; Forming Operations & Terms; Hand Forming; Bending | — | — | Reading the drawing — GEN-B Concepts §4 |
S13 |
Perform a repair on a damaged aluminum sheet | Damage classification, patching, stressed-skin repair | Ch. 4 — Skin Repair; Repair of Stressed Skin Structure; Damage Repairable by Patching; Assessment of Damage | — | Ch. 4 — Section 4. Metal Repair Procedures | Whether this repair is major — GEN-I Procedures Procedure 1 |
The operative sources
- The aircraft's structural repair manual. It defines what repairs are permitted, to what limits, with what materials and fasteners. A repair outside it needs approved data (GEN-I Concepts §3).
- AC 43.13-1B where the SRM is silent, and only within the limits the AC sets for itself. Its paragraph 1 restricts it to nonpressurized areas, and applies only when there are no manufacturer repair or maintenance instructions. It "generally pertains to minor repairs"; for a major repair it "may only be used as a basis for FAA approval". The common summary — that the AC is acceptable data and never approved data — is wrong. Paragraph 1 says the repair data "may also be used as approved data", with the chapter, page and paragraph entered in block 8 of FAA Form 337, when all three of these hold: the user has determined it is appropriate to the product being repaired; it is directly applicable to the repair being made; and it is not contrary to the manufacturer's data. Whether those three hold is a judgment to be made and recorded, not a box to assume.
- The drawing or SRM figure for material call-outs (GEN-B Procedures Procedure 5).
Rules of thumb, all subordinate to the SRM
| --- | --- | --- | --- |
|---|---|---|---|
| Rivet diameter | About three times the thickness of the thicker sheet | ||
| Rivet length | Grip length plus about one and a half diameters, for the shop head | ||
| Formed shop head | About 1.5 diameters across and 0.5 diameters high | ||
| Edge distance | Not less than two diameters from center to edge; about 2.5 typical | ||
| Pitch and transverse pitch | From the SRM or AC 43.13-1B |
These are starting points for checking your own work, not authority. The SRM governs.
License
CC BY-SA 4.0 (Licensing).