SKYWALKER, EXPLOSION - MEDIUM SET-OFF WITH WHISTLE

This's a Skywalker Sound sound effect.

TV Series

 * Star Wars: Clone Wars (Heard once in CHAPTER 12 and CHAPTER 17)
 * Star Wars: Rebels (Heard once briefly in "Fighter Flight")
 * The Young Indiana Jones Chronicles (Heard a few times in "Trenches of Hell")

Movies

 * Backdraft (1991)
 * Con Air (1997)
 * Mars Attacks! (1996)
 * Star Wars: Episode VII - The Forces Awakens (2015)
 * Terminator 2: Judgment Day (1991)
 * Titan A.E. (2000)
 * Willow (1988) (debut?)
 * Young Indiana Jones and the Trenches of Hell (1997)

Trailers

 * Star Wars: Rebels - Season One (2014) (Trailers) (Heard briefly in an excerpt from "Fighter Flight")

Commercials

 * Star Wars .Com (2000) (featured on the Star Wars Trilogy 2000 VHS tapes)

Audio Samples
None so far, but Titan A.E. (see image) and Star Wars: Clone Wars (2003) have some good sources for reference of this particular sound.