8501. here is what we know. right before this crash, the pilot contacted air traffic control and requested a change en route to avoid a storm. the controllers let him change course but not his altitude because reportedly there were other planes in the area. after that they lost communication entirely. combined pilot and co-pilot of 8501 have flown more than 80,000 hours. nbc news aviation analyst john cox joins us the ceo of safety operating systems. thanks for joining us today. >> my pleasure. good to be here. >> let's start with a very basic question people often wonder about, whether they're passengers or following a story like this. walk us through what the pilot is doing and what's going through their mind as they enter that emergency scenario those last few moments we know about that i just described. >> well we don't really know yet what occurred. we know this much. we know that the monsoon season