meshkati, last question. what more can congress do to encourage both the faa and manufacturers like boeing to take direct responsibility for the safety of aircraft and our aviation system? >> i believe that the congress and this committee needs to keep the, essentially, the pressure on to make sure that the waivers are not granted on safety-related issues, for example. that would be a good thing, because they -- right now there are a handful of waivers on the max that directly affect safety. but you need to keep the spotlight on this, because -- and during our interviews we heard often the sentiment expressed, yeah, this is happening now, but as soon as everybody moves on to something else, we're going to go back to the way things were. and that can't happen. as you say, it's too expensive, and the cost in human lives is just way too high. >> thank you, senator. that is also related to an earlier question by senator cantwell. i think what congress can do, that's related to sms. there's a document signed by th