This's a Skywalker Sound sound effect, probably designed by Gary Rydstrom as it debuted in Baby's Day Out (1994).
It is very similar to Sound Ideas, WHINE, CARTOON - SHELL SCREAMING WHINE DOWN and sounds like a shorter version of that whistle, but it is NOT to be confused with the MGM sound, as this is an original recording.
- Baby's Day Out (1994) (debut?) (Heard as Veeko falls from the construction building after launched over a construction elevator)
- A Bug's Life (1998)
- Hoodwinked! (2005) (Heard in a high pitch/low volume as the "Dynamite Express" falls into the river)
(Placeholder until a cleaner sample is found.)