Helicopter SFX — WuxiaScrub
Source: https://opengameart.org/content/helicopter-sfx
Original: https://opengameart.org/sites/default/files/heli_0.ogg
License: CC0 1.0 — https://creativecommons.org/publicdomain/zero/1.0/
Derived rotor loop: mono conversion, six-second segment, seam blend and level normalization.
