Definition
A thin layer of one metal bonded permanently to the surface of another metal to take advantage of properties of both. In aircraft construction, a thin coating of pure aluminum is rolled onto both sides of a high-strength aluminum alloy sheet to protect the corrosion-prone alloy core from oxidation and corrosion.
Plain English
A protective skin of pure aluminum bonded onto the outside of a stronger but more corrosion-prone aluminum alloy sheet. The strong alloy gives the sheet its strength; the pure aluminum on the surface keeps it from corroding.
Context Anchor
Seen in aircraft structures, sheet-metal repair, corrosion inspection, and descriptions of aluminum aircraft skin.
Derivation
From the Old English 'clathian,' meaning 'to clothe.' Cladding literally means putting a layer of clothing on the metal — a protective outer skin over the structural material underneath.
Why Pilots Care
Prevents hidden corrosion that can weaken airframe structures and lead to in-flight failures or expensive repairs.
Analogy
Cladding is like a protective coating on a tool handle: the inside gives it strength, and the outside helps protect it from damage. The key difference is that aircraft cladding is metal bonded to metal, not just paint on a surface.
Intuition Check
Do not think of cladding as paint or a removable cover. In aircraft metal, it is usually a thin protective metal layer bonded directly to the base metal.
Example Sentence 1
The mechanic warned the apprentice not to sand too aggressively, because cutting through the cladding would expose the alloy underneath to corrosion.
Example Sentence 2
Clad aluminum is the standard material chosen for most fuselage skins because the outer layer resists oxidation.