What type of machine-sewed seams are commonly used in aircraft covering?

The most commonly used machine-sewed seams in aircraft covering are plain overlap seams and folded fell seams. Plain overlap seams are straightforward constructions that simply overlap two pieces of fabric and sew them together. This type of seam provides a strong bond, which is essential for the durability and integrity of aircraft coverings subjected to various stresses and environmental conditions.

Folded fell seams are also particularly favored in aircraft applications because they provide additional strength and a neat finish. This type of seam is made by folding over the edge of the fabric and sewing it down, which can also help to minimize fraying and protect the edges from wear and tear. Both of these seams offer the necessary structural support and finish that is crucial for the safety and performance of aircraft, especially in the demanding environments they operate in.

Other seam types listed, while they may have applications in various textile uses, do not typically serve as the main types for aircraft coverings.