The third tutorial in the curriculum. Four of Airframe's artifact-verified elements are here, and riveting is the clearest hand skill in the certificate: it improves visibly with repetition and the coupon shows its own quality permanently.
The course work is done in the shop, at the structures and finishes bench, during the Airframe in-person course. Nothing for this unit is posted to you. If you can get sheet, rivets and a rivet gun, practicing at home beforehand is worthwhile and entirely optional; the sessions below work either way.
Read AF-A Procedures first. This tells you what your first attempts will actually look like.
You will need a second pair of hands, or a bucking bar holder. Bucking is a two-person job until it is not.
Session 1 — Drilling straight, before any rivets
Materials: scrap aluminum sheet, clecos, drills, deburring tool.
- Clamp two pieces together. Cleco every third hole as you drill.
- Drill ten holes. Deburr both sides of every one.
- Separate the sheets and look at the hole alignment.
- Now do ten more without clecoing and separate them again.
What you will see: the unclecoed set drifts. By hole ten the two sheets no longer line up, and no amount of care with the drill fixes it.
What you are learning: clecoing is not tidiness. It is what makes the holes in two sheets be the same holes.
Session 2 — Layout, and where the error goes
- Lay out a row of twelve rivets along a 300 mm edge, working from one end.
- Measure the edge distance of the last rivet.
- Lay out the same row working from the center outward.
- Measure again.
What you will see: the first method dumps all the accumulated error onto the last rivet, and it will often be out of edge-distance limits. The second shares it.
Expect to be surprised by how much error accumulates over twelve holes.
Session 3 — The first rivets
Materials: two pieces of scrap, drilled and clecoed, solid rivets, gun, bucking bar, sets.
- Check rivet length — grip plus about one and a half diameters. Lay one against the stack and look.
- Support the manufactured head with the set, square to the surface.
- Have your partner hold the bar square and firm against the shank.
- Drive in short bursts. Stop and look.
- Measure the shop head: about 1.5 diameters across, 0.5 high.
What will be wrong on your first attempts:
| What you will see | What it means |
|---|---|
| Shop head too small and tall | Under-driven. More bursts |
| Shop head flat and wide, sheet dented around it | Over-driven. Stop sooner |
| Shop head offset to one side | Bucking bar held at an angle |
| Rivet bent over inside the joint | Rivet too long, or bar not square |
| Smiley marks around the manufactured head | Rivet set at an angle, or set slipped |
| Sheets not pulled together | Not clecoed adjacent to the rivet, or rivet too short |
Expect the first ten to be scrap. Drill them out (Session 5) and do it again — that is two skills for the price of one.
Session 4 — Consistency, on separate days
Drive ten consecutive good rivets. Then leave it a day and do it again. Then leave three days and do it again.
Do not do it all in one sitting. The skill being built is the one still present in a month (the residential block specification, superseded 2026-09-18).
When you are ready: ten consecutive rivets with shop heads within limits, no smileys, sheets pulled tight, made on at least two different days.
Session 5 — Removing rivets without losing the hole
This is the session that protects real aircraft.
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Take a coupon of rivets you drove badly.
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Center-punch the head, supporting the sheet behind.
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Drill the head only, to head depth, with a drill matching the shank.
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Break the head off sideways with a pin punch.
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Drive the shank out, supporting behind.
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Measure the hole. Is it still round? Still original size?
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Now deliberately drill one straight through, the fast way. Measure that hole.
What you will see: the second hole is oversized, probably oval, possibly elongated into the sheet. On an aircraft that costs you the next rivet size up, which changes the pattern and may change whether the panel is repairable at all (AF-A Concepts §4).
Session 6 — Countersinking, and the knife edge
- Set a countersink stop and cut into scrap of the same thickness.
- Fit a rivet dry and run a fingernail across it. Adjust until flush.
- Now deliberately cut one too deep. Look at the sheet around the hole from the back.
What you will see: the metal thins to a knife edge. That hole is now a crack initiation site, and the sheet is scrap.
What you are learning: flush is a narrow target with a hard limit on one side. Slightly proud is a defect; slightly deep is a bigger one.
Session 7 — A patch (S6)
The integrative artifact. Everything above, in one piece.
- Design it: patch size, material and thickness, rivet size, pattern, edge distance.
- Lay it out, center outward.
- Drill and cleco, working the pattern.
- Countersink if the scheme calls for it.
- Deburr, clean, prime the faying surfaces (GEN-G Concepts §3).
- Rivet.
- Inspect every shop head.
What will be wrong: the pattern. Almost everyone's first patch has correct rivets in a layout that does not meet edge distance somewhere, usually at a corner.
What you make in the shop
| Element | Artifact |
|---|---|
S1 |
A coupon of ten solid rivets, sheets pulled tight |
S2 |
A coupon of blind rivets, stems within limits |
S12 |
A countersunk coupon with rivets fitted flush |
S6 |
One patch, to the supplied dimensions and pattern |
Keep the scrap too, with a note on what went wrong with each piece, and show it to the instructor. A student who can look at a smiley and say "set at an angle" has learned the unit; one who hands in four good coupons and cannot say why the fifth failed has learned a motion.
License
CC BY-SA 4.0 (Licensing).