What is aircraft sheet metal?
The aluminum alloys used in the construction of aircraft are very strong and relatively light in weight. Sheet metal construction is used on a large majority of aircraft in one form or another. Often tube and fabric airplanes will have aluminum cowlings, fairings, etc.
What is basic principle of sheet metal repair?
Remove all dirt, grease, and paint from the damaged and surrounding areas to determine the exact condition of each rivet, bolt, and weld. Inspect skin for wrinkles throughout a large area. Check the operation of all movable parts in the area. Determine if repair would be the best procedure.
What does a aircraft sheet metal mechanic do?
A sheet metal mechanic who works in aviation deals with all of the sheet metal found on the plane. This may involve removing the metal, bending it, cutting it, and reinstalling it. They can also work in various fabricating plants, factories and construction.
How do you repair cracked sheet metal?
To repair the crack, after you stop drill it, rivet a small sheet metal patch of the same type and thickness metal over the crack to restore the area’s strength and to keep vibration from acting on it further (see Figure 1). If you have a crack in a 0.032-inch aluminum skin, stop drill both ends of the crack.
What are the different metals used in sheet metal construction in aircraft?
Metal aircraft utilize aluminum alloy, magnesium, titanium, stainless steel, aluminum alloy bonded sandwich (honeycomb), glass fiber, advanced composite materials, and other exotic materials.
What are the types of damage and defects in sheet metal?
Pitting—sharp, localized breakdown (small, deep cavity) of metal surface, usually with defined edges. Scratch—slight tear or break in metal surface from light, momentary contact by foreign material. Score—deeper (than scratch) tear or break in metal surface from contact under pressure.
What is the minimum edge distance for aircraft rivet?
The minimum edge distance for universal rivets is 2 times the diameter of the rivet; the minimum edge distance for countersunk rivets is 2 1⁄2 times the diameter of the rivet. If rivets are placed too close to the edge of the sheet, the sheet may crack or pull away from the rivets.
How do you become an aircraft sheet metal mechanic?
To become an aircraft sheet mechanic, you need at least a high school diploma or equivalent and some mechanic training. Many aspiring aircraft sheet mechanics complete a certificate program in welding or metalworking at a vocational school or community college.
What are the duties of a sheet metal worker?
Duties
- Building and installing products such as eaves-troughs, air and heat ducts, roof decking and sheet metal buildings.
- Laying out, measuring and marking sheet metal.
- Working with computerized equipment to cut, bend or straighten sheet metal.
- Welding sheet metal parts.
- Polishing seams, joints and rough surfaces.
What is a flush patch?
Flush Patch. A flush patch is a filler patch that is flush to the skin when applied it is supported by and riveted to a reinforcement plate which is, in turn, riveted to the inside of the skin. Figure 4-177 shows a typical flush patch repair.
What causes weld cracking?
The major cause of a crack is when internal stresses exceed the strength of the weld metal, the base metal, or both. And once a focal point for these stresses—that is, a stress riser—develops and accumulates, a crack can propagate.
What are the uses of aluminum sheet metal in aircraft?
Generally, sheet metal made of aluminum alloys is used in airframe sections that serve as both the structure and outer aircraft covering, with the metal parts joined with rivets or other types of fasteners.
What materials are used in aircraft construction?
As discussed in Chapter 3, Aircraft Fabric Covering, sheet metal aircraft construction dominates modern aviation. Generally, sheet metal made of aluminum alloys is used in airframe sections that serve as both the structure and outer aircraft covering, with the metal parts joined with rivets or other types of fasteners.
What causes damage to metal aircraft structures?
4-2 Damage to metal aircraft structures is often caused by corrosion, erosion, normal stress, and accidents and mishaps. Sometimes aircraft structure modifications require extensive structural rework.
How to make structural repairs on an aircraft?
To make a structural repair, the aircraft technician needs a good working knowledge of sheet metal forming methods and techniques. In general, forming means changing the shape by bending and forming solid metal. In the case of aluminum, this is usually done at room temperature.