Definition
A method of permanently joining metal parts by heating them to a temperature high enough to melt the edges, allowing the molten metal to flow together and fuse into a single piece as it cools. A filler rod of compatible metal is often added to build up the joint. Common aviation methods include oxyacetylene (gas) welding, electric arc welding, and tungsten inert gas (TIG) welding.
Plain English
Joining two pieces of metal by melting their edges so they flow together and become one solid piece when they cool.
Context Anchor
Seen in aircraft maintenance and repair, especially with steel tube structures, engine mounts, exhaust parts, brackets, and other metal components.
Derivation
From Old English 'weallan,' meaning 'to boil' or 'to well up' -- describing how molten metal rises and flows together at the joint. The image fits: the metal becomes liquid and merges before resolidifying as one piece.
Why Pilots Care
Many critical aircraft structures -- engine mounts, landing gear components, exhaust systems, steel-tube fuselages -- are welded assemblies. A poor weld is a structural failure waiting to happen, which is why aircraft welding requires certified technicians and approved procedures.
Intuition Check
Do not treat welding as just any way of sticking metal together. In welding, the metal pieces themselves are joined at the joint; soldering, brazing, bolts, and adhesives are different kinds of joining.
Example Sentence 1
The mechanic inspected the welding on the engine mount for cracks during the annual inspection.
Example Sentence 2
Welding repairs to the fuselage longerons required post-weld heat treatment.