To get that "jet plane" sound (if that isn't your flanger's normal sound), you'll need a flanger with a feedback (somtimes labled resonance) control, like a Boss BF-2, a MXR Flange, or one of those new Ibanez ones. Just set the depth knob to about 1:30- 2:00, turn the level ( or "regen") to 3:00 or higher, set the speed to what you want, then mess with the feedback knob 'till you're satisfied.
As for the Van-Halen "Eruption" sound, that's an MXR Phase 90, not a flange.