Definition
A surface defect in a transparent plastic, such as an aircraft windshield or window, in which a cloudy or hazy film appears on the surface. Bloom is caused by moisture or other contaminants being absorbed into the plastic, and it reduces visibility through the material.
Plain English
A foggy or cloudy haze that forms on the surface of a plastic windshield or window, making it harder to see through.
Context Anchor
Seen in aircraft finishing, paint inspection, fabric covering work, and maintenance write-ups about surface condition.
Derivation
From the older English use of 'bloom' to describe the soft, dusty film that forms on the skin of fruit such as grapes or plums. The aviation use borrows that image directly: a faint, hazy coating on an otherwise clear surface.
Why Pilots Care
A windshield with bloom can scatter light and reduce visibility, especially when flying into the sun or at night. Recognizing it helps a pilot decide whether the windshield needs cleaning, polishing, or replacement before flight.
Analogy
It is like a clear window fogging over. The surface is still there, but moisture has made it look cloudy instead of clear.
Intuition Check
Bloom does not mean a flower or growth here. It means a cloudy haze in a coating or finish.
Example Sentence 1
During preflight, the pilot noticed bloom on the left side of the windshield and asked maintenance to polish it before the next flight.
Example Sentence 2
During overhaul the inspector checked every bloom-prone area on the crankshaft for signs of overheating.