public void collide(TreeSet<Planes> planeSet) {

		// disables in the plane is landing
		if (landing) {
			return;
		}

		Iterator<Planes> planeSetIter = planeSet.iterator();

		warning = false;
		collide = false;

		while (planeSetIter.hasNext()) {
			Planes nextPlane = planeSetIter.next();
			if (nextPlane == this) {
				continue;
			}
			float distance = Position.distance(this.pos, 
					nextPlane.getPosition());

			if (distance < 25 && !nextPlane.isLanding()) {
				collide = true;
			} else if (distance < 75 && !nextPlane.isLanding()) {
				warning = true;
			}
		}
	}