you have talked about this a little bit at the end of last week and also today, that there have been a couple helicopter borne u.s. facilitated movements. one from a group that was very close to the airport and i know that was described as elsewhere in kabul. should we expect there to be more of those? that obviously seems like a tidy answer to it, from those of us looking from this distance, or is there something that's particularly dangerous about those helicopter airlifts that we don't understand that will continue to be quite limited? >> well, the commanders on the ground have the authorities they need to pursue opportunities to bring people in. and one of the means at their disposals, of course, is rotary aircraft helicopters, and we have done that on a couple occasions. i certainly wouldn't rule out we would do it again if it was the best way. that's what it comes down to, what is the best, most effective, and safest way to get americans and other siv applicants into the airport. so again, sometimes helicopters are had answer. sometimes not.