[dimarik]

Например, в словаре.

 
private const _tweens:Dictionary = new Dictionary();
 
// или в массиве
//private const _tweens:Array = new Array();
 
private function nextTween():void {
    const tween:Tween = new Tween();
    this._tweens[tween] = true;
    //this._tweens.push(tween);
    tween.addEventListener(TweenEvent.MOTION_FINISH, this.handler_tweenComplete, false, int.MAX_VALUE);
    tween.start();
}
 
private function handler_tweenComplete(event:Event):void {
    const tween:Tween = event.target as Tween;
    delete this._tweens[tween];
    //this._tweens.splice(this._tweens.indexOf(tween), 1);
}